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9 daysMerge tag 'hyperv-next-signed-20260621' of ↵Linus Torvalds2-3/+6
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv updates from Wei Liu: - Use wakeup mailbox to boot APs in Hyper-V VTL2 TDX guests (Yunhong Jiang, Ricardo Neri) - Move the Hyper-V IOMMU to its own subdirectory (Mukesh Rathor) - Cosmetic changes to mshv and balloon driver (Junrui Luo, Markus Elfring) * tag 'hyperv-next-signed-20260621' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: mshv: add bounds check on vp_index in mshv_intercept_isr() hv_balloon: Simplify data output in hv_balloon_debug_show() x86/hyperv: Cosmetic changes in irqdomain.c for readability iommu/hyperv: Create hyperv subdirectory under drivers/iommu x86/hyperv/vtl: Use the wakeup mailbox to boot secondary CPUs x86/hyperv/vtl: Mark the wakeup mailbox page as private x86/acpi: Add a helper to get the address of the wakeup mailbox x86/hyperv/vtl: Setup the 64-bit trampoline for TDX guests x86/realmode: Make the location of the trampoline configurable x86/hyperv/vtl: Set real_mode_header in hv_vtl_init_platform() x86/dt: Parse the Wakeup Mailbox for Intel processors dt-bindings: reserved-memory: Wakeup Mailbox for Intel processors x86/acpi: Add functions to setup and access the wakeup mailbox x86/topology: Add missing struct declaration and attribute dependency
2026-06-15Merge tag 'x86-msr-2026-06-14' of ↵Linus Torvalds1-2/+2
gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip Pull x86/msr updates from Ingo Molnar: - Large series to reorganize the rdmsr/wrmsr APIs to remove 32-bit variants and convert to 64-bit variants (Juergen Gross) - Fix W=1 warning (HyeongJun An) * tag 'x86-msr-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: x86/msr: Remove wrmsrl() x86/msr: Switch wrmsrl() users to wrmsrq() x86/msr: Remove rdmsrl() x86/msr: Switch rdmsrl() users to rdmsrq() x86/msr: Remove wrmsr_safe_on_cpu() x86/msr: Switch wrmsr_safe_on_cpu() users to wrmsrq_safe_on_cpu() x86/msr: Remove rdmsr_safe_on_cpu() x86/msr: Switch rdmsr_safe_on_cpu() users to rdmsrq_safe_on_cpu() x86/msr: Don't use rdmsr_safe_on_cpu() in rdmsrq_safe_on_cpu() x86/msr: Remove wrmsr_on_cpu() x86/msr: Switch wrmsr_on_cpu() users to wrmsrq_on_cpu() x86/msr: Remove rdmsr_on_cpu() x86/msr: Switch rdmsr_on_cpu() users to rdmsrq_on_cpu() x86/msr: Remove rdmsrl_on_cpu() x86/msr: Switch rdmsrl_on_cpu() user to rdmsrq_on_cpu() x86/process: Convert rdmsr() to rdmsrq() in arch_post_acpi_subsys_init() to address W=1 warning
2026-06-15Merge tag 'driver-core-7.2-rc1' of ↵Linus Torvalds1-33/+10
gitolite.kernel.org:pub/scm/linux/kernel/git/driver-core/driver-core Pull driver core updates from Danilo Krummrich: "Deferred probe: - Fix race where deferred probe timeout work could be permanently canceled by using mod_delayed_work() - Fix missing jiffies conversion in deferred_probe_extend_timeout() - Guard timeout extension with delayed_work_pending() to prevent premature firing - Use system_percpu_wq instead of the deprecated system_wq - Update deferred_probe_timeout documentation device: - Replace direct struct device bitfield access (can_match, dma_iommu, dma_skip_sync, dma_ops_bypass, state_synced, dma_coherent, of_node_reused, offline, offline_disabled) with flag-based accessors using bit operations - Reject devices with unregistered buses - Delete unused DEVICE_ATTR_PREALLOC() - Add low-level device attribute macros with const show/store callbacks, allowing device attributes to reside in read-only memory - Move core device attributes to read-only memory - Constify group array pointers in driver_add_groups() / driver_remove_groups(), struct bus_type, and struct device_driver device property: - Fix fwnode reference leak in fwnode_graph_get_endpoint_by_id() - Initialize all fields of fwnode_handle in fwnode_init() - Provide swnode_get()/swnode_put() wrappers around kobject_get/put() - Allow passing struct software_node_ref_args pointers directly to PROPERTY_ENTRY_REF() driver_override: - Migrate amba, cdx, vmbus, and rpmsg to the generic driver_override infrastructure, fixing a UAF from unsynchronized access to driver_override in bus match() callbacks - Remove the now-unused driver_set_override() firmware loader: - Fix recursive lock deadlock in device_cache_fw_images() when async work falls back to synchronous execution - Fix device reference leak in firmware_upload_register() platform: - Pass KBUILD_MODNAME through the platform driver registration macro to create module symlinks in sysfs for built-in drivers; move module_kset initialization to a pure_initcall and tegra cbb registration to core_initcall to ensure correct ordering - Pass THIS_MODULE implicitly through a coresight_init_driver() macro sysfs: - Upgrade OOB write detection in sysfs_kf_seq_show() from printk to WARN - Add return value clamping to sysfs_kf_read() Rust: - ACPI: Fix missing match data for PRP0001 by exporting acpi_of_match_device() - Auxiliary: Replace drvdata() with dedicated registration data on auxiliary_device. drvdata() exposed the driver's bus device private data beyond the driver's own scope, creating ordering constraints and forcing the data to outlive all registrations that access it. Registration data is instead scoped structurally to the Registration object, making lifecycle ordering enforced by construction rather than convention. - Rust-native device driver lifetimes (HRT): Allow Rust device drivers to carry a lifetime parameter on their bus device private data, tied to the device binding scope -- the interval during which a bus device is bound to a driver. Device resources like pci::Bar<'a> and IoMem<'a> can be stored directly in the driver's bus device private data with a lifetime bounded by the binding scope, so the compiler enforces at build time that they do not outlive the binding. This removes Devres indirection from every access site and eliminates try_access() failure paths in destructors. Bus driver traits use a Generic Associated Type (GAT) Data<'bound> to introduce the lifetime on the private data, rather than parameterizing the Driver trait itself. Auxiliary registration data, where the lifetime is not introduced by a trait callback but must be threaded through Registration, uses the ForLt trait (a type-level abstraction for types generic over a lifetime). Misc: - Fix DT overlayed devices not probing by reverting the broken treewide overlay fix and re-running fw_devlink consumer pickup when an overlay is applied to a bound device - Use root_device_register() for faux bus root device; add sanity check for failed bus init - Fix dev_has_sync_state() data race with READ_ONCE() and move it to base.h - Avoid spurious device_links warning when removing a device while its supplier is unbinding - Switch ISA bus to dynamic root device - Fix suspicious RCU usage in kernfs_put() - Remove devcoredump exit callback - Constify devfreq_event_class" * tag 'driver-core-7.2-rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/driver-core/driver-core: (81 commits) software node: allow passing reference args to PROPERTY_ENTRY_REF() driver core: platform: set mod_name in driver registration coresight: pass THIS_MODULE implicitly through a macro kernel: param: initialize module_kset in a pure_initcall soc/tegra: cbb: Move driver registration from pure_initcall to core_initcall firmware_loader: Fix recursive lock in device_cache_fw_images() driver core: Use system_percpu_wq instead of system_wq driver core: remove driver_set_override() rpmsg: use generic driver_override infrastructure Drivers: hv: vmbus: use generic driver_override infrastructure cdx: use generic driver_override infrastructure amba: use generic driver_override infrastructure rust: devres: add 'static bound to Devres<T> samples: rust: rust_driver_auxiliary: showcase lifetime-bound registration data rust: auxiliary: generalize Registration over ForLt rust: types: add `ForLt` trait for higher-ranked lifetime support gpu: nova-core: separate driver type from driver data samples: rust: rust_driver_pci: use HRT lifetime for Bar rust: io: make IoMem and ExclusiveIoMem lifetime-parameterized rust: pci: make Bar lifetime-parameterized ...
2026-06-08x86/msr: Switch wrmsrl() users to wrmsrq()Juergen Gross1-1/+1
wrmsrl() is a deprecated synonym for wrmsrq(). Switch its users to wrmsrq(). Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Sean Christopherson <seanjc@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Dexuan Cui <decui@microsoft.com> Cc: Long Li <longli@microsoft.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Link: https://patch.msgid.link/20260608082809.3492719-4-jgross@suse.com
2026-06-08x86/msr: Switch rdmsrl() users to rdmsrq()Juergen Gross1-1/+1
rdmsrl() is a deprecated synonym for rdmsrq(). Switch its users to rdmsrq(). Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Dexuan Cui <decui@microsoft.com> Cc: Long Li <longli@microsoft.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Link: https://patch.msgid.link/20260608082809.3492719-2-jgross@suse.com
2026-06-07mshv: add bounds check on vp_index in mshv_intercept_isr()Junrui Luo1-0/+5
mshv_intercept_isr() extracts vp_index from the hypervisor message payload and uses it directly to index into pt_vp_array without validation. handle_bitset_message() and handle_pair_message() already validate vp_index against MSHV_MAX_VPS before array access. Add the same MSHV_MAX_VPS bounds check for consistency with the other message handlers. Fixes: 621191d709b1 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs") Reported-by: Yuhao Jiang <danisjiang@gmail.com> Signed-off-by: Junrui Luo <moonafterrain@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-06-07hv_balloon: Simplify data output in hv_balloon_debug_show()Markus Elfring1-3/+1
Move the specification for a line break from a seq_puts() call to a seq_printf() call. The source code was transformed by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Reviewed-by: Sahil Chandna <sahilchandna@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-05-30Drivers: hv: vmbus: use generic driver_override infrastructureDanilo Krummrich1-33/+10
When a driver is probed through __driver_attach(), the bus' match() callback is called without the device lock held, thus accessing the driver_override field without a lock, which can cause a UAF. Fix this by using the driver-core driver_override infrastructure taking care of proper locking internally. Note that calling match() from __driver_attach() without the device lock held is intentional. [1] Tested-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/driver-core/DGRGTIRHA62X.3RY09D9SOK77P@kernel.org/ [1] Reported-by: Gui-Dong Han <hanguidong02@gmail.com> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220789 Fixes: d765edbb301c ("vmbus: add driver_override support") Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://patch.msgid.link/20260505133935.3772495-4-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-05-27mshv: support 1G hugepages by passing them as 2M-aligned chunksAnirudh Rayabharam (Microsoft)1-16/+13
The hypervisor's map GPA hypercall coalesces contiguous 2M-aligned chunks into 1G mappings when alignment permits, so the driver can support 1G hugepages by feeding them in as 2M chunks. Note that this is the only way to make 1G mappings; there is no way to directly map a 1G hugepage using the hypercall. Always emit a 2M (PMD_ORDER) stride for the huge-page case. The hypercall has no 1G stride, so 1G folios are processed as a sequence of 2M chunks. Folios whose order is less than PMD_ORDER (e.g. mTHP) fall back to single-page stride; mapping them as 2M would fail in the hypervisor anyway. Assisted-by: Copilot-CLI:claude-opus-4.7 Signed-off-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Acked-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-05-27Drivers: hv: vmbus: Improve the logic of reserving fb_mmio on Gen2 VMsDexuan Cui1-3/+26
If vmbus_reserve_fb() in the kdump/kexec kernel fails to properly reserve the framebuffer MMIO range (which is below 4GB) due to a Gen2 VM's screen.lfb_base being zero [1], there is an MMIO conflict between the drivers hyperv-drm and pci-hyperv: when the driver pci-hyperv's hv_allocate_config_window() calls vmbus_allocate_mmio() to get an MMIO range, typically it gets a 32-bit MMIO range that overlaps with the framebuffer MMIO range, and later hv_pci_enter_d0() fails with an error message "PCI Pass-through VSP failed D0 Entry with status" since the host thinks that PCI devices must not use MMIO space that the host has assigned to the framebuffer. This is especially an issue if pci-hyperv is built-in and hyperv-drm is built as a module. Consequently, the kdump/kexec kernel fails to detect PCI devices via pci-hyperv, and may fail to mount the root file system, which may reside in a NVMe disk. The issue described here has existed for SR-IOV VF NICs since day one of the pci-hyperv driver, and has been worked around on x64 when possible. With the recent introduction of ARM64 VMs that boot from NVMe, there is no workaround, so we need a formal fix. On Gen2 VMs, if the screen.lfb_base is 0 in the kdump/kexec kernel [1], fall back to the low MMIO base, which should be equal to the framebuffer MMIO base [2] (the statement is true according to my testing on x64 Windows Server 2016, and on x64 and ARM64 Windows Server 2025 and on Azure. I checked with the Hyper-V team and they said the statement should continue to be true for Gen2 VMs). In the first kernel, screen.lfb_base is not 0; if the user specifies a very high resolution, it's not enough to only reserve 8MB: let's always reserve half of the space below 4GB, but cap the reservation to 128MB, which is the required framebuffer size of the highest resolution 7680*4320 supported by Hyper-V. While at it, fix the comparison "end > VTPM_BASE_ADDRESS" by changing the > to >=. Here the 'end' is an inclusive end (typically, it's 0xFFFF_FFFF for the low MMIO range). Note: vmbus_reserve_fb() now also reserves an MMIO range at the beginning of the low MMIO range on CVMs, which have no framebuffers (the 'screen.lfb_base' in vmbus_reserve_fb() is 0 for CVMs), just in case the host might treat the beginning of the low MMIO range specially [3]. BTW, the OpenHCL kernel is not affected by the change, because that kernel boots with DeviceTree rather than ACPI (so vmbus_reserve_fb() won't run there), and there is no framebuffer device for that kernel. Note: normally Gen1 VMs don't have the MMIO conflict issue because the framebuffer MMIO range (which is hardcoded to base=4GB-128MB and size=64MB for Gen1 VMs by the host) is always reported via the legacy PCI graphics device's BAR, so the kdump/kexec kernel can reserve the 64MB MMIO range; however, if the VM is configured to use a very high resolution and the required framebuffer size exceeds 64MB (AFAIK, in practice, this isn't a typical configuration by users), the hyperv-drm driver may need to allocate an MMIO range above 4GB and change the framebuffer MMIO location to the allocated MMIO range -- in this case, there can still be issues [4] which can't be easily fixed: any possible affected Gen1 users would have to use a resolution whose framebuffer size is <= 64MB, or switch to Gen2 VMs. [1] https://lore.kernel.org/all/SA1PR21MB692176C1BC53BFC9EAE5CF8EBF51A@SA1PR21MB6921.namprd21.prod.outlook.com/ [2] https://lore.kernel.org/all/SA1PR21MB69218F955B62DFF62E3E88D2BF222@SA1PR21MB6921.namprd21.prod.outlook.com/ [3] https://lore.kernel.org/all/SN6PR02MB415726B17D5A6027CD1717E8D4342@SN6PR02MB4157.namprd02.prod.outlook.com/ [4] https://lore.kernel.org/all/SA1PR21MB69213486F821CA5A2C793C81BF342@SA1PR21MB6921.namprd21.prod.outlook.com/ Fixes: 4daace0d8ce8 ("PCI: hv: Add paravirtual PCI front-end for Microsoft Hyper-V VMs") CC: stable@vger.kernel.org Reviewed-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Krister Johansen <kjlx@templeofstupid.com> Tested-by: Matthew Ruffell <matthew.ruffell@canonical.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-05-27mshv: use kmalloc_array in mshv_root_scheduler_initCan Peng1-1/+1
Replace kmalloc() with kmalloc_array() to prevent potential overflow, as recommended in Documentation/process/deprecated.rst. No functional change. Signed-off-by: Can Peng <pengcan@kylinos.cn> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-05-27mshv: Add conditional VMBus dependencyMichael Kelley1-0/+1
When the VMBus driver is not part of the kernel (CONFIG_HYPERV_VMBUS=n), the MSHV root driver fails to link: ERROR: modpost: "hv_vmbus_exists" [drivers/hv/mshv_root.ko] undefined! Fix this while meeting these requirements: * It must be possible to include the MSHV root driver without the VMBus driver. In such case, the MSHV root driver can be built-in to the kernel image, or it can be built as a separate module. * If both the MSHV root driver and the VMBus driver are present, the MSHV root driver and VMBus driver can both be built-in, or they can both be separate modules. Or the MSHV root driver can be a module while the VMBus driver can be built-in, but the reverse is disallowed. Regardless of the build choices, the VMBus driver must be loaded before the MSHV driver in order for the SynIC to be managed properly (see comments in the MSHV SynIC code). The fix has two parts: * Add a Kconfig entry for MSHV_ROOT to depend on HYPERV_VMBUS if HYPERV_VMBUS is present. The entry disallows MSHV_ROOT being built-in when HYPERV_VMBUS is a module, but without requiring that HYPERV_VMBUS be built. * Add a stub implementation of hv_vmbus_exists() for when the VMBus driver is not present so that the MSHV root driver has no module dependency on VMBus. When the VMBus driver *is* present, the module dependency ensures that the VMBus driver loads first when both are built as modules. Existing code ensures that the VMBus driver loads first if it is built-in. The VMBus driver uses subsys_initcall(), which is initcall level 4. The MSHV root driver uses module_init(), which becomes device_init() when built-in, and device_init() is initcall level 6. Reported-by: Arnd Bergmann <arnd@arndb.de> Closes: https://lore.kernel.org/all/20260520074044.923728-1-arnd@kernel.org/ Signed-off-by: Michael Kelley <mhklinux@outlook.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Jork Loeser <jloeser@linux.microsoft.com> Reviewed-by: Hardik Garg <hargar@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-05-13Drivers: hv: vmbus: Provide option to skip VMBus unload on panicMichael Kelley3-8/+19
Currently, VMBus code initiates a VMBus unload in the panic path so that if a kdump kernel is loaded, it can start fresh in setting up its own VMBus connection. However, a driver for the VMBus virtual frame buffer may need to flush dirty portions of the frame buffer back to the Hyper-V host so that panic information is visible in the graphics console. To support such flushing, provide exported functions for the frame buffer driver to specify that the VMBus unload should not be done by the VMBus driver, and to initiate the VMBus unload itself. Together these allow a frame buffer driver to delay the VMBus unload until after it has completed the flush. Ideally, the VMBus driver could use its own panic-path callback to do the unload after all frame buffer drivers have finished. But DRM frame buffer drivers use the kmsg dump callback, and there are no callbacks after that in the panic path. Hence this somewhat messy approach to properly sequencing the frame buffer flush and the VMBus unload. Fixes: 3671f3777758 ("drm/hyperv: Add support for drm_panic") Signed-off-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Long Li <longli@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-29mshv: unmap debugfs stats pages on kexecJork Loeser2-1/+7
On L1VH, debugfs stats pages are overlay pages: the kernel allocates them and registers the GPAs with the hypervisor via HVCALL_MAP_STATS_PAGE2. These overlay mappings persist in the hypervisor across kexec. If the kexec'd kernel reuses those physical pages, the hypervisor's overlay semantics cause a machine check exception. Fix this by calling mshv_debugfs_exit() from the reboot notifier, which issues HVCALL_UNMAP_STATS_PAGE for each mapped stats page before kexec. This releases the overlay bindings so the physical pages can be safely reused. Guard mshv_debugfs_exit() against being called when init failed. Signed-off-by: Jork Loeser <jloeser@linux.microsoft.com> Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-29mshv: clean up SynIC state on kexec for L1VHJork Loeser1-3/+0
The reboot notifier that tears down the SynIC cpuhp state guards the cleanup with hv_root_partition(), so on L1VH (where hv_root_partition() is false) SINT0, SINT5, and SIRBP are never cleaned up before kexec. The kexec'd kernel then inherits stale unmasked SINTs and an enabled SIRBP pointing to freed memory. Remove the hv_root_partition() guard so the cleanup runs for all parent partitions. Signed-off-by: Jork Loeser <jloeser@linux.microsoft.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-29mshv: limit SynIC management to MSHV-owned resourcesJork Loeser2-50/+103
The SynIC is shared between VMBus and MSHV. VMBus owns the message page (SIMP), event flags page (SIEFP), global enable (SCONTROL), and SINT2. MSHV adds SINT0, SINT5, and the event ring page (SIRBP). Currently mshv_synic_cpu_init() redundantly enables SIMP, SIEFP, and SCONTROL that VMBus already configured, and mshv_synic_cpu_exit() disables all of them. This is wrong because MSHV can be torn down while VMBus is still active. In particular, a kexec reboot notifier tears down MSHV first. Disabling SCONTROL, SIMP, and SIEFP out from under VMBus causes its later cleanup to write SynIC MSRs while SynIC is disabled, which the hypervisor does not tolerate. Restrict MSHV to managing only the resources it owns: - SINT0, SINT5: mask on cleanup, unmask on init - SIRBP: enable/disable as before - SIMP, SIEFP, SCONTROL: leave to VMBus when it is active (L1VH and nested root partition); on a non-nested root partition VMBus does not run, so MSHV must enable/disable them While here, fix the SIEFP and SIRBP memremap() and virt_to_phys() calls to use HV_HYP_PAGE_SHIFT/HV_HYP_PAGE_SIZE instead of PAGE_SHIFT/PAGE_SIZE. The hypervisor always uses 4K pages for SynIC register GPAs regardless of the kernel page size, so using PAGE_SHIFT produces wrong addresses on ARM64 with 64K pages. Note that initialization order matters - VMBUS first, MSHV second, and the reverse on de-init. Ideally, we would want a dedicated SYNIC driver that replaces the cross-dependencies with a clear API and dynamic tracking. Such refactor should go into its own dedicated series, outside of this kexec fix series. Signed-off-by: Jork Loeser <jloeser@linux.microsoft.com> Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-29hv: utils: replace deprecated strcpy with strscpy in kvp_registerThorsten Blum1-4/+2
strcpy() has been deprecated [1] because it performs no bounds checking on the destination buffer, which can lead to buffer overflows. While the current code works correctly, replace strcpy() with the safer strscpy() to follow secure coding best practices. Use ->body.kvp_register.version directly as the destination buffer and remove the local variable. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strcpy Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-29hv: utils: handle and propagate errors in kvp_registerThorsten Blum1-12/+13
Make kvp_register() return an error code instead of silently ignoring failures, and propagate the error from kvp_handle_handshake() instead of returning success. This propagates both kzalloc_obj() and hvutil_transport_send() failures to kvp_handle_handshake() and thus to kvp_on_msg(). Fixes: 245ba56a52a3 ("Staging: hv: Implement key/value pair (KVP)") Cc: stable@vger.kernel.org Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Reviewed-by: Long Li <longli@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-24Merge tag 'drm-fixes-2026-04-24' of https://gitlab.freedesktop.org/drm/kernelLinus Torvalds1-1/+1
Pull more drm fixes from Dave Airlie: "These are the regular fixes that have built up over last couple of weeks, all pretty minor and spread all over. atomic: - raise the vblank timeout to avoid it on virtual drivers - fix colorop duplication bridge: - stm_lvds: state check fix - dw-mipi-dsi: bridge reference leak fix panel: - visionx-rm69299: init fix dma-fence: - fix sparse warning dma-buf: - UAF fix panthor: - mapping fix arcgpu: - device_node reference leak fix nouveau: - memory leak in error path fix - overflow in reloc path for old hw fix hv: - Kconfig fix v3d: - infinite loop fix" * tag 'drm-fixes-2026-04-24' of https://gitlab.freedesktop.org/drm/kernel: drm/nouveau: fix u32 overflow in pushbuf reloc bounds check MAINTAINERS: split hisilicon maintenance and add Yongbang Shi for hibmc-drm matainers drm/v3d: Reject empty multisync extension to prevent infinite loop drm/panel: visionox-rm69299: Make use of prepare_prev_first drm/drm_atomic: duplicate colorop states if plane color pipeline in use drm/nouveau: fix nvkm_device leak on aperture removal failure hv: Select CONFIG_SYSFB only for CONFIG_HYPERV_VMBUS dma-fence: Silence sparse warning in dma_fence_describe drm/bridge: dw-mipi-dsi: Fix bridge leak when host attach fails drm/arcpgu: fix device node leak drm/panthor: Fix outdated function documentation drm/panthor: Extend VM locked region for remap case to be a superset dma-buf: fix UAF in dma_buf_put() tracepoint drm/bridge: stm_lvds: Do not fail atomic_check on disabled connector drm/atomic: Increase timeout in drm_atomic_helper_wait_for_vblanks()
2026-04-24Merge tag 'drm-misc-fixes-2026-04-23' of ↵Dave Airlie1-1/+1
https://gitlab.freedesktop.org/drm/misc/kernel into drm-fixes This week in drm-misc-fixes, we have: - A patch to raise the vblank timeout to avoid it on virtual drivers - a state check fix for stm_lvds - a use-after-free fix for dma-buf - a mapping fix for panthor - a device_node reference leak fix for arcgpu - a bridge reference leak fix for dw-mipi-dsi - a sparse warning fix for dma-fence - a kconfig fix for hv - a memory leak fix for nouveau - a fix to duplicate colorop when duplicating states - a panel initialisation order fix for visionox-rm69299 - a fix to prevent an infinite loop for v3d - an overflow fix for nouveau Signed-off-by: Dave Airlie <airlied@redhat.com> From: Maxime Ripard <mripard@redhat.com> Link: https://patch.msgid.link/20260423-realistic-eager-reindeer-4dacf7@houat
2026-04-22Merge tag 'hyperv-next-signed-20260421' of ↵Linus Torvalds13-45/+741
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull Hyper-V updates from Wei Liu: - Fix cross-compilation for hv tools (Aditya Garg) - Fix vmemmap_shift exceeding MAX_FOLIO_ORDER in mshv_vtl (Naman Jain) - Limit channel interrupt scan to relid high water mark (Michael Kelley) - Export hv_vmbus_exists() and use it in pci-hyperv (Dexuan Cui) - Fix cleanup and shutdown issues for MSHV (Jork Loeser) - Introduce more tracing support for MSHV (Stanislav Kinsburskii) * tag 'hyperv-next-signed-20260421' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: x86/hyperv: Skip LP/VP creation on kexec x86/hyperv: move stimer cleanup to hv_machine_shutdown() Drivers: hv: vmbus: fix hyperv_cpuhp_online variable shadowing mshv: Add tracepoint for GPA intercept handling mshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER tools: hv: Fix cross-compilation Drivers: hv: vmbus: Export hv_vmbus_exists() and use it in pci-hyperv mshv: Introduce tracing support Drivers: hv: vmbus: Limit channel interrupt scan to relid high water mark
2026-04-22x86/hyperv: Skip LP/VP creation on kexecJork Loeser1-0/+47
After a kexec the logical processors and virtual processors already exist in the hypervisor because they were created by the previous kernel. Attempting to add them again causes either a BUG_ON or corrupted VP state leading to MCEs in the new kernel. Add hv_lp_exists() to probe whether an LP is already present by calling HVCALL_GET_LOGICAL_PROCESSOR_RUN_TIME. When it succeeds the LP exists and we skip the add-LP and create-VP loops entirely. Also add hv_call_notify_all_processors_started() which informs the hypervisor that all processors are online. This is required after adding LPs (fresh boot) and is a no-op on kexec since we skip that path. Co-developed-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com> Signed-off-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com> Co-developed-by: Stanislav Kinsburskii <stanislav.kinsburskii@gmail.com> Signed-off-by: Stanislav Kinsburskii <stanislav.kinsburskii@gmail.com> Co-developed-by: Mukesh Rathor <mrathor@linux.microsoft.com> Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com> Signed-off-by: Jork Loeser <jloeser@linux.microsoft.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-22x86/hyperv: move stimer cleanup to hv_machine_shutdown()Jork Loeser1-1/+0
Move hv_stimer_global_cleanup() from vmbus's hv_kexec_handler() to hv_machine_shutdown() in the platform code. This ensures stimer cleanup happens before the vmbus unload, which is required for root partition kexec to work correctly. Co-developed-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com> Signed-off-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com> Signed-off-by: Jork Loeser <jloeser@linux.microsoft.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-22Drivers: hv: vmbus: fix hyperv_cpuhp_online variable shadowingJork Loeser1-1/+0
vmbus_alloc_synic_and_connect() declares a local 'int hyperv_cpuhp_online' that shadows the file-scope global of the same name. The cpuhp state returned by cpuhp_setup_state() is stored in the local, leaving the global at 0 (CPUHP_OFFLINE). When hv_kexec_handler() or hv_machine_shutdown() later call cpuhp_remove_state(hyperv_cpuhp_online) they pass 0, which hits the BUG_ON in __cpuhp_remove_state_cpuslocked(). Remove the local declaration so the cpuhp state is stored in the file-scope global where hv_kexec_handler() and hv_machine_shutdown() expect it. Fixes: 2647c96649ba ("Drivers: hv: Support establishing the confidential VMBus connection") Signed-off-by: Jork Loeser <jloeser@linux.microsoft.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-22mshv: Add tracepoint for GPA intercept handlingStanislav Kinsburskii2-2/+33
Provide visibility into GPA intercept operations for debugging and performance analysis of Microsoft Hypervisor guest memory management. Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-15Merge tag 'mm-stable-2026-04-13-21-45' of ↵Linus Torvalds3-15/+22
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - "maple_tree: Replace big node with maple copy" (Liam Howlett) Mainly prepararatory work for ongoing development but it does reduce stack usage and is an improvement. - "mm, swap: swap table phase III: remove swap_map" (Kairui Song) Offers memory savings by removing the static swap_map. It also yields some CPU savings and implements several cleanups. - "mm: memfd_luo: preserve file seals" (Pratyush Yadav) File seal preservation to LUO's memfd code - "mm: zswap: add per-memcg stat for incompressible pages" (Jiayuan Chen) Additional userspace stats reportng to zswap - "arch, mm: consolidate empty_zero_page" (Mike Rapoport) Some cleanups for our handling of ZERO_PAGE() and zero_pfn - "mm/kmemleak: Improve scan_should_stop() implementation" (Zhongqiu Han) A robustness improvement and some cleanups in the kmemleak code - "Improve khugepaged scan logic" (Vernon Yang) Improve khugepaged scan logic and reduce CPU consumption by prioritizing scanning tasks that access memory frequently - "Make KHO Stateless" (Jason Miu) Simplify Kexec Handover by transitioning KHO from an xarray-based metadata tracking system with serialization to a radix tree data structure that can be passed directly to the next kernel - "mm: vmscan: add PID and cgroup ID to vmscan tracepoints" (Thomas Ballasi and Steven Rostedt) Enhance vmscan's tracepointing - "mm: arch/shstk: Common shadow stack mapping helper and VM_NOHUGEPAGE" (Catalin Marinas) Cleanup for the shadow stack code: remove per-arch code in favour of a generic implementation - "Fix KASAN support for KHO restored vmalloc regions" (Pasha Tatashin) Fix a WARN() which can be emitted the KHO restores a vmalloc area - "mm: Remove stray references to pagevec" (Tal Zussman) Several cleanups, mainly udpating references to "struct pagevec", which became folio_batch three years ago - "mm: Eliminate fake head pages from vmemmap optimization" (Kiryl Shutsemau) Simplify the HugeTLB vmemmap optimization (HVO) by changing how tail pages encode their relationship to the head page - "mm/damon/core: improve DAMOS quota efficiency for core layer filters" (SeongJae Park) Improve two problematic behaviors of DAMOS that makes it less efficient when core layer filters are used - "mm/damon: strictly respect min_nr_regions" (SeongJae Park) Improve DAMON usability by extending the treatment of the min_nr_regions user-settable parameter - "mm/page_alloc: pcp locking cleanup" (Vlastimil Babka) The proper fix for a previously hotfixed SMP=n issue. Code simplifications and cleanups ensued - "mm: cleanups around unmapping / zapping" (David Hildenbrand) A bunch of cleanups around unmapping and zapping. Mostly simplifications, code movements, documentation and renaming of zapping functions - "support batched checking of the young flag for MGLRU" (Baolin Wang) Batched checking of the young flag for MGLRU. It's part cleanups; one benchmark shows large performance benefits for arm64 - "memcg: obj stock and slab stat caching cleanups" (Johannes Weiner) memcg cleanup and robustness improvements - "Allow order zero pages in page reporting" (Yuvraj Sakshith) Enhance free page reporting - it is presently and undesirably order-0 pages when reporting free memory. - "mm: vma flag tweaks" (Lorenzo Stoakes) Cleanup work following from the recent conversion of the VMA flags to a bitmap - "mm/damon: add optional debugging-purpose sanity checks" (SeongJae Park) Add some more developer-facing debug checks into DAMON core - "mm/damon: test and document power-of-2 min_region_sz requirement" (SeongJae Park) An additional DAMON kunit test and makes some adjustments to the addr_unit parameter handling - "mm/damon/core: make passed_sample_intervals comparisons overflow-safe" (SeongJae Park) Fix a hard-to-hit time overflow issue in DAMON core - "mm/damon: improve/fixup/update ratio calculation, test and documentation" (SeongJae Park) A batch of misc/minor improvements and fixups for DAMON - "mm: move vma_(kernel|mmu)_pagesize() out of hugetlb.c" (David Hildenbrand) Fix a possible issue with dax-device when CONFIG_HUGETLB=n. Some code movement was required. - "zram: recompression cleanups and tweaks" (Sergey Senozhatsky) A somewhat random mix of fixups, recompression cleanups and improvements in the zram code - "mm/damon: support multiple goal-based quota tuning algorithms" (SeongJae Park) Extend DAMOS quotas goal auto-tuning to support multiple tuning algorithms that users can select - "mm: thp: reduce unnecessary start_stop_khugepaged()" (Breno Leitao) Fix the khugpaged sysfs handling so we no longer spam the logs with reams of junk when starting/stopping khugepaged - "mm: improve map count checks" (Lorenzo Stoakes) Provide some cleanups and slight fixes in the mremap, mmap and vma code - "mm/damon: support addr_unit on default monitoring targets for modules" (SeongJae Park) Extend the use of DAMON core's addr_unit tunable - "mm: khugepaged cleanups and mTHP prerequisites" (Nico Pache) Cleanups to khugepaged and is a base for Nico's planned khugepaged mTHP support - "mm: memory hot(un)plug and SPARSEMEM cleanups" (David Hildenbrand) Code movement and cleanups in the memhotplug and sparsemem code - "mm: remove CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE and cleanup CONFIG_MIGRATION" (David Hildenbrand) Rationalize some memhotplug Kconfig support - "change young flag check functions to return bool" (Baolin Wang) Cleanups to change all young flag check functions to return bool - "mm/damon/sysfs: fix memory leak and NULL dereference issues" (Josh Law and SeongJae Park) Fix a few potential DAMON bugs - "mm/vma: convert vm_flags_t to vma_flags_t in vma code" (Lorenzo Stoakes) Convert a lot of the existing use of the legacy vm_flags_t data type to the new vma_flags_t type which replaces it. Mainly in the vma code. - "mm: expand mmap_prepare functionality and usage" (Lorenzo Stoakes) Expand the mmap_prepare functionality, which is intended to replace the deprecated f_op->mmap hook which has been the source of bugs and security issues for some time. Cleanups, documentation, extension of mmap_prepare into filesystem drivers - "mm/huge_memory: refactor zap_huge_pmd()" (Lorenzo Stoakes) Simplify and clean up zap_huge_pmd(). Additional cleanups around vm_normal_folio_pmd() and the softleaf functionality are performed. * tag 'mm-stable-2026-04-13-21-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits) mm: fix deferred split queue races during migration mm/khugepaged: fix issue with tracking lock mm/huge_memory: add and use has_deposited_pgtable() mm/huge_memory: add and use normal_or_softleaf_folio_pmd() mm: add softleaf_is_valid_pmd_entry(), pmd_to_softleaf_folio() mm/huge_memory: separate out the folio part of zap_huge_pmd() mm/huge_memory: use mm instead of tlb->mm mm/huge_memory: remove unnecessary sanity checks mm/huge_memory: deduplicate zap deposited table call mm/huge_memory: remove unnecessary VM_BUG_ON_PAGE() mm/huge_memory: add a common exit path to zap_huge_pmd() mm/huge_memory: handle buggy PMD entry in zap_huge_pmd() mm/huge_memory: have zap_huge_pmd return a boolean, add kdoc mm/huge: avoid big else branch in zap_huge_pmd() mm/huge_memory: simplify vma_is_specal_huge() mm: on remap assert that input range within the proposed VMA mm: add mmap_action_map_kernel_pages[_full]() uio: replace deprecated mmap hook with mmap_prepare in uio_info drivers: hv: vmbus: replace deprecated mmap hook with mmap_prepare mm: allow handling of stacked mmap_prepare hooks in more drivers ...
2026-04-15hv: Select CONFIG_SYSFB only for CONFIG_HYPERV_VMBUSThomas Zimmermann1-1/+1
Hyperv's sysfb access only exists in the VMBUS support. Therefore only select CONFIG_SYSFB for CONFIG_HYPERV_VMBUS. Avoids sysfb code on systems that don't need it. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Fixes: 96959283a58d ("Drivers: hv: Always select CONFIG_SYSFB for Hyper-V guests") Cc: Michael Kelley <mhklinux@outlook.com> Cc: Saurabh Sengar <ssengar@linux.microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Long Li <longli@microsoft.com> Cc: linux-hyperv@vger.kernel.org Cc: <stable@vger.kernel.org> # v6.16+ Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com> Link: https://patch.msgid.link/20260402092305.208728-2-tzimmermann@suse.de
2026-04-14Merge tag 'irq-core-2026-04-12' of ↵Linus Torvalds2-6/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core irq updates from Thomas Gleixner: - Invoke add_interrupt_randomness() in handle_percpu_devid_irq() and cleanup the workaround in the Hyper-V driver, which would now invoke it twice on ARM64. Removing it from the driver requires to add it to the x86 system vector entry point - Remove the pointles cpu_read_lock() around reading CPU possible mask, which is read only after init - Add documentation for the interaction between device tree bindings and the interrupt type defines in irq.h - Delete stale defines in the matrix allocator and the equivalent in loongarch * tag 'irq-core-2026-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Drivers: hv: Move add_interrupt_randomness() to hypervisor callback sysvec genirq/chip: Invoke add_interrupt_randomness() in handle_percpu_devid_irq() genirq/affinity: Remove cpus_read_lock() while reading cpu_possible_mask genirq/matrix, LoongArch: Delete IRQ_MATRIX_BITS leftovers genirq: Document interaction between <linux/irq.h> and DT binding defines
2026-04-14mshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDERNaman Jain1-3/+9
When registering VTL0 memory via MSHV_ADD_VTL0_MEMORY, the kernel computes pgmap->vmemmap_shift as the number of trailing zeros in the OR of start_pfn and last_pfn, intending to use the largest compound page order both endpoints are aligned to. However, this value is not clamped to MAX_FOLIO_ORDER, so a sufficiently aligned range (e.g. physical range [0x800000000000, 0x800080000000), corresponding to start_pfn=0x800000000 with 35 trailing zeros) can produce a shift larger than what memremap_pages() accepts, triggering a WARN and returning -EINVAL: WARNING: ... memremap_pages+0x512/0x650 requested folio size unsupported The MAX_FOLIO_ORDER check was added by commit 646b67d57589 ("mm/memremap: reject unreasonable folio/compound page sizes in memremap_pages()"). Fix this by clamping vmemmap_shift to MAX_FOLIO_ORDER so we always request the largest order the kernel supports, in those cases, rather than an out-of-range value. Also fix the error path to propagate the actual error code from devm_memremap_pages() instead of hard-coding -EFAULT, which was masking the real -EINVAL return. Fixes: 7bfe3b8ea6e3 ("Drivers: hv: Introduce mshv_vtl driver") Cc: stable@vger.kernel.org Signed-off-by: Naman Jain <namjain@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-14Drivers: hv: vmbus: Export hv_vmbus_exists() and use it in pci-hypervDexuan Cui1-12/+8
With commit f84b21da3624 ("PCI: hv: Don't load the driver for baremetal root partition"), the bare metal Linux root partition won't use the pci-hyperv driver, but when a Linux VM runs on the Linux root partition, pci-hyperv's module_init function init_hv_pci_drv() can still run, e.g. in the case of CONFIG_PCI_HYPERV=y, even if the VMBus driver is not used in such a VM (i.e. the hv_vmbus driver's init function returns -ENODEV due to vmbus_root_device being NULL). In such a Linux VM, init_hv_pci_drv() runs with a side effect: the 3 hvpci_block_ops callbacks are set to functions that depend on hv_vmbus. Later, when the MLX driver in such a VM invokes the callbacks, e.g. in drivers/net/ethernet/mellanox/mlx5/core/lib/hv.c: mlx5_hv_register_invalidate(), hvpci_block_ops.reg_blk_invalidate() is hv_register_block_invalidate() rather than a NULL function pointer, and hv_register_block_invalidate() assumes that it can find a struct hv_pcibus_device from pdev->bus->sysdata, which is false in such a VM. Consequently, hv_register_block_invalidate() -> get_pcichild_wslot() -> spin_lock_irqsave() may hang since it can be accessing an invalid spinlock pointer. Fix the issue by exporting hv_vmbus_exists() and using it in pci-hyperv: hv_root_partition() is true and hv_nested is false ==> hv_vmbus_exists() is false. hv_root_partition() is true and hv_nested is true ==> hv_vmbus_exists() is true. hv_root_partition() is false ==> hv_vmbus_exists() is true. While at it, rename vmbus_exists() to hv_vmbus_exists() to follow the convention that all public functions have the hv_ prefix; also change the return value's type from int to bool to make the code more readable; also move the two pr_info() calls. Reported-by: Mukesh Rathor <mrathor@linux.microsoft.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-14mshv: Introduce tracing supportStanislav Kinsburskii8-15/+629
Introduces various trace events and use them in the corresponding places in the driver. Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-14Drivers: hv: vmbus: Limit channel interrupt scan to relid high water markMichael Kelley3-11/+15
When checking for VMBus channel interrupts, current code always scans the full SynIC receive interrupt bit array to get the relid of the interrupting channels. The array has HV_EVENT_FLAGS_COUNT (2048) bits. But VMs rarely have more than 100 channels, and the relid is typically a small integer that is densely assigned by the Hyper-V host. It's wasteful to scan 2048 bits when it is highly unlikely that anything will be found past bit 100. The waste is double with Confidential VMBus because there are two receive interrupt arrays that must be scanned: one for the hypervisor SynIC and one for the paravisor SynIC. Improve the scanning by tracking the largest relid that has been offered by the Hyper-V host. Then when checking for VMBus channel interrupts, only scan up to this high water mark. When channels are rescinded, it's not worth the complexity to recalculate the high water mark. Hyper-V tends to reuse the rescinded relids for any new channels that are subsequently added, and the performance benefit of exactly tracking the high water mark would be minimal. Signed-off-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Roman Kisel <vdso@mailbox.org> Reviewed-by: Roman Kisel <vdso@mailbox.org> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-05drivers: hv: vmbus: replace deprecated mmap hook with mmap_prepareLorenzo Stoakes (Oracle)2-14/+21
The f_op->mmap interface is deprecated, so update the vmbus driver to use its successor, mmap_prepare. This updates all callbacks which referenced the function pointer hv_mmap_ring_buffer to instead reference hv_mmap_prepare_ring_buffer, utilising the newly introduced compat_set_desc_from_vma() and __compat_vma_mmap() to be able to implement this change. The UIO HV generic driver is the only user of hv_create_ring_sysfs(), which is the only function which references vmbus_channel->mmap_prepare_ring_buffer which, in turn, is the only external interface to hv_mmap_prepare_ring_buffer. This patch therefore updates this caller to use mmap_prepare instead, which also previously used vm_iomap_memory(), so this change replaces it with its mmap_prepare equivalent, mmap_action_simple_ioremap(). [akpm@linux-foundation.org: restore struct vmbus_channel comment, per Michael Kelley] Link: https://lkml.kernel.org/r/05467cb62267d750e5c770147517d4df0246cda6.1774045440.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bodo Stroesser <bostroesser@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Clemens Ladisch <clemens@ladisch.de> Cc: David Hildenbrand <david@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Long Li <longli@microsoft.com> Cc: Marc Dionne <marc.dionne@auristor.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Richard Weinberger <richard@nod.at> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vignesh Raghavendra <vigneshr@ti.com> Cc: Wei Liu <wei.liu@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-05hv_balloon: set unspecified page reporting orderYuvraj Sakshith1-1/+1
Explicitly mention page reporting order to be set to default value using PAGE_REPORTING_ORDER_UNSPECIFIED fallback value. Link: https://lkml.kernel.org/r/20260303113032.3008371-4-yuvraj.sakshith@oss.qualcomm.com Signed-off-by: Yuvraj Sakshith <yuvraj.sakshith@oss.qualcomm.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Eugenio Pérez <eperezma@redhat.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Long Li <longli@microsoft.com> Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Liu <wei.liu@kernel.org> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-04Drivers: hv: Move add_interrupt_randomness() to hypervisor callback sysvecMichael Kelley2-6/+0
The Hyper-V ISRs, for normal guests and when running in the hypervisor root patition, are calling add_interrupt_randomness() as a primary source of entropy. The call is currently in the ISRs as a common place to handle both x86/x64 and arm64. On x86/x64, hypervisor interrupts come through a custom sysvec entry, and do not go through a generic interrupt handler. On arm64, hypervisor interrupts come through an emulated GICv3. GICv3 uses the generic handler handle_percpu_devid_irq(), which does not do add_interrupt_randomness() -- unlike its counterpart handle_percpu_irq(). But handle_percpu_devid_irq() is now updated to do the add_interrupt_randomness(). So add_interrupt_randomness() is now needed only in Hyper-V's x86/x64 custom sysvec path. Move add_interrupt_randomness() from the Hyper-V ISRs into the Hyper-V x86/x64 custom sysvec path, matching the existing STIMER0 sysvec path. With this change, add_interrupt_randomness() is no longer called from any device drivers, which is appropriate. Signed-off-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Acked-by: Wei Liu <wei.liu@kernel.org> Link: https://patch.msgid.link/20260402202400.1707-3-mhklkml@zohomail.com
2026-04-04mshv: Fix infinite fault loop on permission-denied GPA interceptsStanislav Kinsburskii1-3/+12
Prevent infinite fault loops when guests access memory regions without proper permissions. Currently, mshv_handle_gpa_intercept() attempts to remap pages for all faults on movable memory regions, regardless of whether the access type is permitted. When a guest writes to a read-only region, the remap succeeds but the region remains read-only, causing immediate re-fault and spinning the vCPU indefinitely. Validate intercept access type against region permissions before attempting remaps. Reject writes to non-writable regions and executes to non-executable regions early, returning false to let the VMM handle the intercept appropriately. This also closes a potential DoS vector where malicious guests could intentionally trigger these fault loops to consume host resources. Fixes: b9a66cd5ccbb ("mshv: Add support for movable memory regions") Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-03-18mshv: Fix error handling in mshv_region_pinStanislav Kinsburskii1-2/+4
The current error handling has two issues: First, pin_user_pages_fast() can return a short pin count (less than requested but greater than zero) when it cannot pin all requested pages. This is treated as success, leading to partially pinned regions being used, which causes memory corruption. Second, when an error occurs mid-loop, already pinned pages from the current batch are not properly accounted for before calling mshv_region_invalidate_pages(), causing a page reference leak. Treat short pins as errors and fix partial batch accounting before cleanup. Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-03-13mshv: Fix use-after-free in mshv_map_user_memory error pathStanislav Kinsburskii1-1/+1
In the error path of mshv_map_user_memory(), calling vfree() directly on the region leaves the MMU notifier registered. When userspace later unmaps the memory, the notifier fires and accesses the freed region, causing a use-after-free and potential kernel panic. Replace vfree() with mshv_partition_put() to properly unregister the MMU notifier before freeing the region. Fixes: b9a66cd5ccbb9 ("mshv: Add support for movable memory regions") Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-03-12mshv: pass struct mshv_user_mem_region by referenceMukesh R1-13/+13
For unstated reasons, function mshv_partition_ioctl_set_memory passes struct mshv_user_mem_region by value instead of by reference. Change it to pass by reference. Signed-off-by: Mukesh R <mrathor@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-03-11Revert "mshv: expose the scrub partition hypercall"Wei Liu1-1/+0
This reverts commit 36d6cbb62133fc6eea28f380409e0fb190f3dfbe. Calling this as a passthrough hypercall leaves the VM in an inconsistent state. Revert before it is released. Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-25mshv: add arm64 support for doorbell & intercept SINTsAnirudh Rayabharam (Microsoft)1-10/+109
On x86, the HYPERVISOR_CALLBACK_VECTOR is used to receive synthetic interrupts (SINTs) from the hypervisor for doorbells and intercepts. There is no such vector reserved for arm64. On arm64, the hypervisor exposes a synthetic register that can be read to find the INTID that should be used for SINTs. This INTID is in the PPI range. To better unify the code paths, introduce mshv_sint_vector_init() that either reads the synthetic register and obtains the INTID (arm64) or just uses HYPERVISOR_CALLBACK_VECTOR as the interrupt vector (x86). Reviewed-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-25mshv: refactor synic init and cleanupAnirudh Rayabharam (Microsoft)3-65/+75
Rename mshv_synic_init() to mshv_synic_cpu_init() and mshv_synic_cleanup() to mshv_synic_cpu_exit() to better reflect that these functions handle per-cpu synic setup and teardown. Use mshv_synic_init/cleanup() to perform init/cleanup that is not per-cpu. Move all the synic related setup from mshv_parent_partition_init. Move the reboot notifier to mshv_synic.c because it currently only operates on the synic cpuhp state. Move out synic_pages from the global mshv_root since its use is now completely local to mshv_synic.c. This is in preparation for adding more stuff to mshv_synic_init(). No functional change. Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-22Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL usesKees Cook1-1/+1
Conversion performed via this Coccinelle script: // SPDX-License-Identifier: GPL-2.0-only // Options: --include-headers-for-types --all-includes --include-headers --keep-comments virtual patch @gfp depends on patch && !(file in "tools") && !(file in "samples")@ identifier ALLOC = {kmalloc_obj,kmalloc_objs,kmalloc_flex, kzalloc_obj,kzalloc_objs,kzalloc_flex, kvmalloc_obj,kvmalloc_objs,kvmalloc_flex, kvzalloc_obj,kvzalloc_objs,kvzalloc_flex}; @@ ALLOC(... - , GFP_KERNEL ) $ make coccicheck MODE=patch COCCI=gfp.cocci Build and boot tested x86_64 with Fedora 42's GCC and Clang: Linux version 6.19.0+ (user@host) (gcc (GCC) 15.2.1 20260123 (Red Hat 15.2.1-7), GNU ld version 2.44-12.fc42) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Linux version 6.19.0+ (user@host) (clang version 20.1.8 (Fedora 20.1.8-4.fc42), LLD 20.1.8) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Signed-off-by: Kees Cook <kees@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21Convert more 'alloc_obj' cases to default GFP_KERNEL argumentsLinus Torvalds2-4/+2
This converts some of the visually simpler cases that have been split over multiple lines. I only did the ones that are easy to verify the resulting diff by having just that final GFP_KERNEL argument on the next line. Somebody should probably do a proper coccinelle script for this, but for me the trivial script actually resulted in an assertion failure in the middle of the script. I probably had made it a bit _too_ trivial. So after fighting that far a while I decided to just do some of the syntactically simpler cases with variations of the previous 'sed' scripts. The more syntactically complex multi-line cases would mostly really want whitespace cleanup anyway. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21Convert 'alloc_obj' family to use the new default GFP_KERNEL argumentLinus Torvalds10-19/+19
This was done entirely with mindless brute force, using git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' | xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/' to convert the new alloc_obj() users that had a simple GFP_KERNEL argument to just drop that argument. Note that due to the extreme simplicity of the scripting, any slightly more complex cases spread over multiple lines would not be triggered: they definitely exist, but this covers the vast bulk of the cases, and the resulting diff is also then easier to check automatically. For the same reason the 'flex' versions will be done as a separate conversion. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook16-42/+38
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-20Merge tag 'hyperv-next-signed-20260218' of ↵Linus Torvalds15-202/+1662
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull Hyper-V updates from Wei Liu: - Debugfs support for MSHV statistics (Nuno Das Neves) - Support for the integrated scheduler (Stanislav Kinsburskii) - Various fixes for MSHV memory management and hypervisor status handling (Stanislav Kinsburskii) - Expose more capabilities and flags for MSHV partition management (Anatol Belski, Muminul Islam, Magnus Kulke) - Miscellaneous fixes to improve code quality and stability (Carlos López, Ethan Nelson-Moore, Li RongQing, Michael Kelley, Mukesh Rathor, Purna Pavan Chandra Aekkaladevi, Stanislav Kinsburskii, Uros Bizjak) - PREEMPT_RT fixes for vmbus interrupts (Jan Kiszka) * tag 'hyperv-next-signed-20260218' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (34 commits) mshv: Handle insufficient root memory hypervisor statuses mshv: Handle insufficient contiguous memory hypervisor status mshv: Introduce hv_deposit_memory helper functions mshv: Introduce hv_result_needs_memory() helper function mshv: Add SMT_ENABLED_GUEST partition creation flag mshv: Add nested virtualization creation flag Drivers: hv: vmbus: Simplify allocation of vmbus_evt mshv: expose the scrub partition hypercall mshv: Add support for integrated scheduler mshv: Use try_cmpxchg() instead of cmpxchg() x86/hyperv: Fix error pointer dereference x86/hyperv: Reserve 3 interrupt vectors used exclusively by MSHV Drivers: hv: vmbus: Use kthread for vmbus interrupts on PREEMPT_RT x86/hyperv: Remove ASM_CALL_CONSTRAINT with VMMCALL insn x86/hyperv: Use savesegment() instead of inline asm() to save segment registers mshv: fix SRCU protection in irqfd resampler ack handler mshv: make field names descriptive in a header struct x86/hyperv: Update comment in hyperv_cleanup() mshv: clear eventfd counter on irqfd shutdown x86/hyperv: Use memremap()/memunmap() instead of ioremap_cache()/iounmap() ...
2026-02-19mshv: Handle insufficient root memory hypervisor statusesStanislav Kinsburskii2-0/+16
When creating guest partition objects, the hypervisor may fail to allocate root partition pages and return an insufficient memory status. In this case, deposit memory using the root partition ID instead. Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Reviewed-by: Mukesh R <mrathor@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-19mshv: Handle insufficient contiguous memory hypervisor statusStanislav Kinsburskii2-0/+5
The HV_STATUS_INSUFFICIENT_CONTIGUOUS_MEMORY status indicates that the hypervisor lacks sufficient contiguous memory for its internal allocations. When this status is encountered, allocate and deposit HV_MAX_CONTIGUOUS_ALLOCATION_PAGES contiguous pages to the hypervisor. HV_MAX_CONTIGUOUS_ALLOCATION_PAGES is defined in the hypervisor headers, a deposit of this size will always satisfy the hypervisor's requirements. Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Reviewed-by: Mukesh R <mrathor@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-19mshv: Introduce hv_deposit_memory helper functionsStanislav Kinsburskii3-20/+29
Introduce hv_deposit_memory_node() and hv_deposit_memory() helper functions to handle memory deposit with proper error handling. The new hv_deposit_memory_node() function takes the hypervisor status as a parameter and validates it before depositing pages. It checks for HV_STATUS_INSUFFICIENT_MEMORY specifically and returns an error for unexpected status codes. This is a precursor patch to new out-of-memory error codes support. No functional changes intended. Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Reviewed-by: Mukesh R <mrathor@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-19mshv: Introduce hv_result_needs_memory() helper functionStanislav Kinsburskii3-16/+25
Replace direct comparisons of hv_result(status) against HV_STATUS_INSUFFICIENT_MEMORY with a new hv_result_needs_memory() helper function. This improves code readability and provides a consistent and extendable interface for checking out-of-memory conditions in hypercall results. No functional changes intended. Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Reviewed-by: Mukesh R <mrathor@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-18mshv: Add SMT_ENABLED_GUEST partition creation flagAnatol Belski1-0/+2
Add support for HV_PARTITION_CREATION_FLAG_SMT_ENABLED_GUEST to allow userspace VMMs to enable SMT for guest partitions. Expose this via new MSHV_PT_BIT_SMT_ENABLED_GUEST flag in the UAPI. Without this flag, the hypervisor schedules guest VPs incorrectly, causing SMT unusable. Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-18mshv: Add nested virtualization creation flagMuminul Islam1-0/+2
Introduce HV_PARTITION_CREATION_FLAG_NESTED_VIRTUALIZATION_CAPABLE to indicate support for nested virtualization during partition creation. This enables clearer configuration and capability checks for nested virtualization scenarios. Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Muminul Islam <muislam@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-18Drivers: hv: vmbus: Simplify allocation of vmbus_evtMichael Kelley1-14/+8
The per-cpu variable vmbus_evt is currently dynamically allocated. It's only 8 bytes, so just allocate it statically to simplify and save a few lines of code. Signed-off-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Long Li <longli@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-18mshv: expose the scrub partition hypercallMagnus Kulke1-0/+1
This hypercall needs to be exposed for VMMs to soft-reboot guests. It will reset APIC and synthetic interrupt controller state, among others. Signed-off-by: Magnus Kulke <magnuskulke@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-18mshv: Add support for integrated schedulerStanislav Kinsburskii1-32/+50
Query the hypervisor for integrated scheduler support and use it if configured. Microsoft Hypervisor originally provided two schedulers: root and core. The root scheduler allows the root partition to schedule guest vCPUs across physical cores, supporting both time slicing and CPU affinity (e.g., via cgroups). In contrast, the core scheduler delegates vCPU-to-physical-core scheduling entirely to the hypervisor. Direct virtualization introduces a new privileged guest partition type - L1 Virtual Host (L1VH) — which can create child partitions from its own resources. These child partitions are effectively siblings, scheduled by the hypervisor's core scheduler. This prevents the L1VH parent from setting affinity or time slicing for its own processes or guest VPs. While cgroups, CFS, and cpuset controllers can still be used, their effectiveness is unpredictable, as the core scheduler swaps vCPUs according to its own logic (typically round-robin across all allocated physical CPUs). As a result, the system may appear to "steal" time from the L1VH and its children. To address this, Microsoft Hypervisor introduces the integrated scheduler. This allows an L1VH partition to schedule its own vCPUs and those of its guests across its "physical" cores, effectively emulating root scheduler behavior within the L1VH, while retaining core scheduler behavior for the rest of the system. The integrated scheduler is controlled by the root partition and gated by the vmm_enable_integrated_scheduler capability bit. If set, the hypervisor supports the integrated scheduler. The L1VH partition must then check if it is enabled by querying the corresponding extended partition property. If this property is true, the L1VH partition must use the root scheduler logic; otherwise, it must use the core scheduler. This requirement makes reading VMM capabilities in L1VH partition a requirement too. Signed-off-by: Andreea Pintilie <anpintil@microsoft.com> Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-18mshv: Use try_cmpxchg() instead of cmpxchg()Uros Bizjak2-4/+4
Use !try_cmpxchg() instead of cmpxchg (*ptr, old, new) != old. x86 CMPXCHG instruction returns success in ZF flag, so this change saves a compare after CMPXCHG. The generated assembly code improves from e.g.: 415: 48 8b 44 24 30 mov 0x30(%rsp),%rax 41a: 48 8b 54 24 38 mov 0x38(%rsp),%rdx 41f: f0 49 0f b1 91 a8 02 lock cmpxchg %rdx,0x2a8(%r9) 426: 00 00 428: 48 3b 44 24 30 cmp 0x30(%rsp),%rax 42d: 0f 84 09 ff ff ff je 33c <...> to: 415: 48 8b 44 24 30 mov 0x30(%rsp),%rax 41a: 48 8b 54 24 38 mov 0x38(%rsp),%rdx 41f: f0 49 0f b1 91 a8 02 lock cmpxchg %rdx,0x2a8(%r9) 426: 00 00 428: 0f 84 0e ff ff ff je 33c <...> No functional change intended. Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Dexuan Cui <decui@microsoft.com> Cc: Long Li <longli@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-18Drivers: hv: vmbus: Use kthread for vmbus interrupts on PREEMPT_RTJan Kiszka1-1/+65
Resolves the following lockdep report when booting PREEMPT_RT on Hyper-V with related guest support enabled: [ 1.127941] hv_vmbus: registering driver hyperv_drm [ 1.132518] ============================= [ 1.132519] [ BUG: Invalid wait context ] [ 1.132521] 6.19.0-rc8+ #9 Not tainted [ 1.132524] ----------------------------- [ 1.132525] swapper/0/0 is trying to lock: [ 1.132526] ffff8b9381bb3c90 (&channel->sched_lock){....}-{3:3}, at: vmbus_chan_sched+0xc4/0x2b0 [ 1.132543] other info that might help us debug this: [ 1.132544] context-{2:2} [ 1.132545] 1 lock held by swapper/0/0: [ 1.132547] #0: ffffffffa010c4c0 (rcu_read_lock){....}-{1:3}, at: vmbus_chan_sched+0x31/0x2b0 [ 1.132557] stack backtrace: [ 1.132560] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.19.0-rc8+ #9 PREEMPT_{RT,(lazy)} [ 1.132565] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 09/25/2025 [ 1.132567] Call Trace: [ 1.132570] <IRQ> [ 1.132573] dump_stack_lvl+0x6e/0xa0 [ 1.132581] __lock_acquire+0xee0/0x21b0 [ 1.132592] lock_acquire+0xd5/0x2d0 [ 1.132598] ? vmbus_chan_sched+0xc4/0x2b0 [ 1.132606] ? lock_acquire+0xd5/0x2d0 [ 1.132613] ? vmbus_chan_sched+0x31/0x2b0 [ 1.132619] rt_spin_lock+0x3f/0x1f0 [ 1.132623] ? vmbus_chan_sched+0xc4/0x2b0 [ 1.132629] ? vmbus_chan_sched+0x31/0x2b0 [ 1.132634] vmbus_chan_sched+0xc4/0x2b0 [ 1.132641] vmbus_isr+0x2c/0x150 [ 1.132648] __sysvec_hyperv_callback+0x5f/0xa0 [ 1.132654] sysvec_hyperv_callback+0x88/0xb0 [ 1.132658] </IRQ> [ 1.132659] <TASK> [ 1.132660] asm_sysvec_hyperv_callback+0x1a/0x20 As code paths that handle vmbus IRQs use sleepy locks under PREEMPT_RT, the vmbus_isr execution needs to be moved into thread context. Open- coding this allows to skip the IPI that irq_work would additionally bring and which we do not need, being an IRQ, never an NMI. This affects both x86 and arm64, therefore hook into the common driver logic. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Reviewed-by: Florian Bezdeka <florian.bezdeka@siemens.com> Tested-by: Florian Bezdeka <florian.bezdeka@siemens.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-14drivers: hv: vmbus_drv: Remove reference to hpyerv_fbPrasanna Kumar T S M1-2/+2
Remove hyperv_fb reference as the driver is removed. Signed-off-by: Prasanna Kumar T S M <ptsm@linux.microsoft.com> Signed-off-by: Helge Deller <deller@gmx.de>
2026-02-09Merge tag 'efi-next-for-v7.0' of ↵Linus Torvalds1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull EFI updates from Ard Biesheuvel: - Quirk the broken EFI framebuffer geometry on the Valve Steam Deck - Capture the EDID information of the primary display also on non-x86 EFI systems when booting via the EFI stub. * tag 'efi-next-for-v7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: efi: Support EDID information sysfb: Move edid_info into sysfb_primary_display sysfb: Pass sysfb_primary_display to devices sysfb: Replace screen_info with sysfb_primary_display sysfb: Add struct sysfb_display_info efi: sysfb_efi: Reduce number of references to global screen_info efi: earlycon: Reduce number of references to global screen_info efi: sysfb_efi: Fix efidrmfb and simpledrmfb on Valve Steam Deck efi: sysfb_efi: Convert swap width and height quirk to a callback efi: sysfb_efi: Fix lfb_linelength calculation when applying quirks efi: sysfb_efi: Replace open coded swap with the macro
2026-02-06mshv: fix SRCU protection in irqfd resampler ack handlerLi RongQing1-2/+3
Replace hlist_for_each_entry_rcu() with hlist_for_each_entry_srcu() in mshv_irqfd_resampler_ack() to correctly handle SRCU-protected linked list traversal. The function uses SRCU (sleepable RCU) synchronization via partition->pt_irq_srcu, but was incorrectly using the RCU variant for list iteration. This could lead to race conditions when the list is modified concurrently. Also add srcu_read_lock_held() assertion as required by hlist_for_each_entry_srcu() to ensure we're in the proper read-side critical section. Fixes: 621191d709b14 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs") Signed-off-by: Li RongQing <lirongqing@baidu.com> Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Acked-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-06mshv: make field names descriptive in a header structMukesh R3-40/+40
When struct fields use very common names like "pages" or "type", it makes it difficult to find uses of these fields with tools like grep, cscope, etc when the struct is in a header file included in many places. Add prefix mreg_ to some fields in struct mshv_mem_region to make it easier to find them. There is no functional change. Signed-off-by: Mukesh R <mrathor@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-04mshv: clear eventfd counter on irqfd shutdownCarlos López2-4/+2
While unhooking from the irqfd waitqueue, clear the internal eventfd counter by using eventfd_ctx_remove_wait_queue() instead of remove_wait_queue(), preventing potential spurious interrupts. This removes the need to store a pointer into the workqueue, as the eventfd already keeps track of it. This mimicks what other similar subsystems do on their equivalent paths with their irqfds (KVM, Xen, ACRN support, etc). Signed-off-by: Carlos López <clopez@suse.de> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-04Drivers: hv: Use memremap()/memunmap() instead of ioremap_cache()/iounmap()Michael Kelley1-6/+6
When running with a paravisor or in the root partition, the SynIC event and message pages are provided by the paravisor or hypervisor respectively, instead of being allocated by Linux. The provided pages are normal memory, but are outside of the physical address space seen by Linux. As such they cannot be accessed via the kernel's direct map, and must be explicitly mapped to a kernel virtual address. Current code uses ioremap_cache() and iounmap() to map and unmap the pages. These functions are for use on I/O address space that may not behave as normal memory, so they generate or expect addresses with the __iomem attribute. For normal memory, the preferred functions are memremap() and memunmap(), which operate similarly but without __iomem. At the time of the original work on CoCo VMs on Hyper-V, memremap() did not support creating a decrypted mapping, so ioremap_cache() was used instead, since I/O address space is always mapped decrypted. memremap() has since been enhanced to allow decrypted mappings, so replace ioremap_cache() with memremap() when mapping the event and message pages. Similarly, replace iounmap() with memunmap(). As a side benefit, the replacement cleans up 'sparse' warnings about __iomem mismatches. The replacement is done to use the correct functions as long-term goodness and to clean up the sparse warnings. No runtime bugs are fixed. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202601170445.JtZQwndW-lkp@intel.com/ Closes: https://lore.kernel.org/oe-kbuild-all/202512150359.fMdmbddk-lkp@intel.com/ Signed-off-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-04mshv: Add debugfs to view hypervisor statisticsNuno Das Neves4-2/+785
Introduce a debugfs interface to expose root and child partition stats when running with mshv_root. Create a debugfs directory "mshv" containing 'stats' files organized by type and id. A stats file contains a number of counters depending on its type. e.g. an excerpt from a VP stats file: TotalRunTime : 1997602722 HypervisorRunTime : 649671371 RemoteNodeRunTime : 0 NormalizedRunTime : 1997602721 IdealCpu : 0 HypercallsCount : 1708169 HypercallsTime : 111914774 PageInvalidationsCount : 0 PageInvalidationsTime : 0 On a root partition with some active child partitions, the entire directory structure may look like: mshv/ stats # hypervisor stats lp/ # logical processors 0/ # LP id stats # LP 0 stats 1/ 2/ 3/ partition/ # partition stats 1/ # root partition id stats # root partition stats vp/ # root virtual processors 0/ # root VP id stats # root VP 0 stats 1/ 2/ 3/ 42/ # child partition id stats # child partition stats vp/ # child VPs 0/ # child VP id stats # child VP 0 stats 1/ 43/ 55/ On L1VH, some stats are not present as it does not own the hardware like the root partition does: - The hypervisor and lp stats are not present - L1VH's partition directory is named "self" because it can't get its own id - Some of L1VH's partition and VP stats fields are not populated, because it can't map its own HV_STATS_AREA_PARENT page. Co-developed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Co-developed-by: Praveen K Paladugu <prapal@linux.microsoft.com> Signed-off-by: Praveen K Paladugu <prapal@linux.microsoft.com> Co-developed-by: Mukesh Rathor <mrathor@linux.microsoft.com> Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com> Co-developed-by: Purna Pavan Chandra Aekkaladevi <paekkaladevi@linux.microsoft.com> Signed-off-by: Purna Pavan Chandra Aekkaladevi <paekkaladevi@linux.microsoft.com> Co-developed-by: Jinank Jain <jinankjain@microsoft.com> Signed-off-by: Jinank Jain <jinankjain@microsoft.com> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Acked-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-04mshv: Add data for printing stats page countersNuno Das Neves1-0/+490
Introduce mshv_debugfs_counters.c, containing static data corresponding to HV_*_COUNTER enums in the hypervisor source. Defining the enum members as an array instead makes more sense, since it will be iterated over to print counter information to debugfs. Include hypervisor, logical processor, partition, and virtual processor counters. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Acked-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-04mshv: Update hv_stats_page definitionsNuno Das Neves1-19/+8
hv_stats_page belongs in hvhdk.h, move it there. It does not require a union to access the data for different counters, just use a single u64 array for simplicity and to match the Windows definitions. While at it, correct the ARM64 value for VpRootDispatchThreadBlocked. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Acked-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-04mshv: Always map child vp stats pages regardless of scheduler typeStanislav Kinsburskii1-17/+8
Currently vp->vp_stats_pages is only used by the root scheduler for fast interrupt injection. Soon, vp_stats_pages will also be needed for exposing child VP stats to userspace via debugfs. Mapping the pages a second time to a different address causes an error on L1VH. Remove the scheduler requirement and always map the vp stats pages. Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Acked-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-04mshv: Improve mshv_vp_stats_map/unmap(), add them to mshv_root.hStanislav Kinsburskii2-16/+53
These functions are currently only used to map child partition VP stats, on root partition. However, they will soon be used on L1VH, and also used for mapping the host's own VP stats. Introduce a helper is_l1vh_parent() to determine whether we are mapping our own VP stats. In this case, do not attempt to map the PARENT area. Note this is a different case than mapping PARENT on an older hypervisor where it is not available at all, so must be handled separately. On unmap, pass the stats pages since on L1VH the kernel allocates them and they must be freed in hv_unmap_stats_page(). Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Acked-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-04mshv: Use typed hv_stats_page pointersStanislav Kinsburskii3-11/+14
Refactor all relevant functions to use struct hv_stats_page pointers instead of void pointers for stats page mapping and unmapping thus improving type safety and code clarity across the Hyper-V stats mapping APIs. Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Acked-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-04mshv: Ignore second stats page map result failurePurna Pavan Chandra Aekkaladevi2-4/+51
Older versions of the hypervisor do not have a concept of separate SELF and PARENT stats areas. In this case, mapping the HV_STATS_AREA_SELF page is sufficient - it's the only page and it contains all available stats. Mapping HV_STATS_AREA_PARENT returns HV_STATUS_INVALID_PARAMETER which currently causes module init to fail on older hypevisor versions. Detect this case and gracefully fall back to populating stats_pages[HV_STATS_AREA_PARENT] with the already-mapped SELF page. Add comments to clarify the behavior, including a clarification of why this isn't needed for hv_call_map_stats_page2() which always supports PARENT and SELF areas. Signed-off-by: Purna Pavan Chandra Aekkaladevi <paekkaladevi@linux.microsoft.com> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Acked-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-04mshv: Use EPOLLIN and EPOLLHUP instead of POLLIN and POLLHUPMichael Kelley1-4/+4
mshv code currently uses the POLLIN and POLLHUP flags. Starting with commit a9a08845e9acb ("vfs: do bulk POLL* -> EPOLL* replacement") the intent is to use the EPOLL* versions throughout the kernel. The comment at the top of mshv_eventfd.c describes it as being inspired by the KVM implementation, which was changed by the above mentioned commit in 2018 to use EPOLL*. mshv_eventfd.c is much newer than 2018 and there's no statement as to why it must use the POLL* versions. So change it to use the EPOLL* versions. This change also resolves a 'sparse' warning. No functional change, and the generated code is the same. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202601220948.MUTO60W4-lkp@intel.com/ Signed-off-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-02-04mshv: Fix compiler warning about cast converting incompatible function typeMichael Kelley1-2/+3
In mshv_vtl_sint_ioctl_pause_msg_stream(), the reference to function mshv_vtl_synic_mask_vmbus_sint() is cast to type smp_call_func_t. The cast generates a compiler warning because the function signature of mshv_vtl_synic_mask_vmbus_sint() doesn't match smp_call_func_t. There's no actual bug here because the mis-matched function signatures are compatible at runtime. Nonetheless, eliminate the compiler warning by changing the function signature of mshv_vtl_synic_mask_vmbus_sint() to match what on_each_cpu() expects. Remove the cast because it is then no longer necessary. No functional change. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202601170352.qbh3EKH5-lkp@intel.com/ Signed-off-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Naman Jain <namjain@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-01-15mshv: handle gpa intercepts for arm64Anirudh Rayabharam (Microsoft)1-7/+8
The mshv driver now uses movable pages for guests. For arm64 guests to be functional, handle gpa intercepts for arm64 too (the current code implements handling only for x86). Move some arch-agnostic functions out of #ifdefs so that they can be re-used. Fixes: b9a66cd5ccbb ("mshv: Add support for movable memory regions") Signed-off-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-01-15mshv: Add __user attribute to argument passed to access_ok()Michael Kelley1-1/+1
access_ok() expects its first argument to have the __user attribute since it is checking access to user space. Current code passes an argument that lacks that attribute, resulting in 'sparse' flagging the incorrect usage. However, the compiler doesn't generate code based on the attribute, so there's no actual bug. In the interest of general correctness and to avoid noise from sparse, add the __user attribute. No functional change. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202512141339.791TCKnB-lkp@intel.com/ Signed-off-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-01-15mshv: Store the result of vfs_poll in a variable of type __poll_tMichael Kelley1-1/+1
vfs_poll() returns a result of type __poll_t, but current code is using an "unsigned int" local variable. The difference is that __poll_t carries the "bitwise" attribute. This attribute is not interpreted by the C compiler; it is only used by 'sparse' to flag incorrect usage of the return value. The return value is used correctly here, so there's no bug, but sparse complains about the type mismatch. In the interest of general correctness and to avoid noise from sparse, change the local variable to type __poll_t. No functional change. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202512141339.791TCKnB-lkp@intel.com/ Signed-off-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-01-15mshv: Align huge page stride with guest mappingStanislav Kinsburskii1-31/+62
Ensure that a stride larger than 1 (huge page) is only used when page points to a head of a huge page and both the guest frame number (gfn) and the operation size (page_count) are aligned to the huge page size (PTRS_PER_PMD). This matches the hypervisor requirement that map/unmap operations for huge pages must be guest-aligned and cover a full huge page. Add mshv_chunk_stride() to encapsulate this alignment and page-order validation, and plumb a huge_page flag into the region chunk handlers. This prevents issuing large-page map/unmap/share operations that the hypervisor would reject due to misaligned guest mappings. Fixes: abceb4297bf8 ("mshv: Fix huge page handling in memory region traversal") Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-01-15Drivers: hv: Always do Hyper-V panic notification in hv_kmsg_dump()Michael Kelley1-5/+7
hv_kmsg_dump() currently skips the panic notification entirely if it doesn't get any message bytes to pass to Hyper-V due to an error from kmsg_dump_get_buffer(). Skipping the notification is undesirable because it leaves the Hyper-V host uncertain about the state of a panic'ed guest. Fix this by always doing the panic notification, even if bytes_written is zero. Also ensure that bytes_written is initialized, which fixes a kernel test robot warning. The warning is actually bogus because kmsg_dump_get_buffer() happens to set bytes_written even if it fails, and in the kernel test robot's CONFIG_PRINTK not set case, hv_kmsg_dump() is never called. But do the initialization for robustness and to quiet the static checker. Fixes: 9c318a1d9b50 ("Drivers: hv: move panic report code from vmbus to hv early init code") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/all/202512172103.OcUspn1Z-lkp@intel.com/ Signed-off-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Roman Kisel <vdso@mailbox.org> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-01-15Drivers: hv: vmbus: fix typo in function name referenceJulia Lawall1-1/+1
Replace cmxchg by cmpxchg. Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr> Reviewed-by: Roman Kisel <vdso@mailbox.org> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-12-18mshv: release mutex on region invalidation failureAnirudh Rayabharam (Microsoft)1-1/+3
In the region invalidation failure path in mshv_region_interval_invalidate(), the region mutex is not released. Fix it by releasing the mutex in the failure path. Signed-off-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Fixes: b9a66cd5ccbb ("mshv: Add support for movable memory regions") Acked-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Roman Kisel <vdso@mailbox.org> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-12-17mshv: hide x86-specific functions on arm64Arnd Bergmann1-0/+2
The hv_sleep_notifiers_register() and hv_machine_power_off() functions are only called and declared on x86, but cause a warning on arm64: drivers/hv/mshv_common.c:210:6: error: no previous prototype for 'hv_sleep_notifiers_register' [-Werror=missing-prototypes] 210 | void hv_sleep_notifiers_register(void) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/hv/mshv_common.c:224:6: error: no previous prototype for 'hv_machine_power_off' [-Werror=missing-prototypes] 224 | void hv_machine_power_off(void) | ^~~~~~~~~~~~~~~~~~~~ Hide both inside of an #ifdef block. Fixes: f0be2600ac55 ("mshv: Use reboot notifier to configure sleep state") Fixes: 615a6e7d83f9 ("mshv: Cleanly shutdown root partition with MSHV") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-12-16sysfb: Replace screen_info with sysfb_primary_displayThomas Zimmermann1-3/+3
Replace the global screen_info with sysfb_primary_display of type struct sysfb_display_info. Adapt all users of screen_info. Instances of screen_info are defined for x86, loongarch and EFI, with only one instance compiled into a specific build. Replace all of them with sysfb_primary_display. All existing users of screen_info are updated by pointing them to sysfb_primary_display.screen instead. This introduces some churn to the code, but has no impact on functionality. Boot parameters and EFI config tables are unchanged. They transfer screen_info as before. The logic in EFI's alloc_screen_info() changes slightly, as it now returns the screen field of sysfb_primary_display. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Bjorn Helgaas <bhelgaas@google.com> # drivers/pci/ Reviewed-by: Richard Lyu <richard.lyu@suse.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2025-12-15mshv: Initialize local variables early upon region invalidationStanislav Kinsburskii1-7/+7
Ensure local variables are initialized before use so that the warning can print the right values if locking the region to invalidate fails due to inability to lock the region. Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Fixes: b9a66cd5ccbb ("mshv: Add support for movable memory regions") Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-12-15mshv: Use PMD_ORDER instead of HPAGE_PMD_ORDER when processing regionsStanislav Kinsburskii1-1/+1
Fix page order determination logic when CONFIG_PGTABLE_HAS_HUGE_LEAVES is undefined, as HPAGE_PMD_SHIFT is defined as BUILD_BUG in that case. Fixes: abceb4297bf8 ("mshv: Fix huge page handling in memory region traversal") Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-12-09Merge tag 'hyperv-next-signed-20251207' of ↵Linus Torvalds21-601/+3305
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv updates from Wei Liu: - Enhancements to Linux as the root partition for Microsoft Hypervisor: - Support a new mode called L1VH, which allows Linux to drive the hypervisor running the Azure Host directly - Support for MSHV crash dump collection - Allow Linux's memory management subsystem to better manage guest memory regions - Fix issues that prevented a clean shutdown of the whole system on bare metal and nested configurations - ARM64 support for the MSHV driver - Various other bug fixes and cleanups - Add support for Confidential VMBus for Linux guest on Hyper-V - Secure AVIC support for Linux guests on Hyper-V - Add the mshv_vtl driver to allow Linux to run as the secure kernel in a higher virtual trust level for Hyper-V * tag 'hyperv-next-signed-20251207' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (58 commits) mshv: Cleanly shutdown root partition with MSHV mshv: Use reboot notifier to configure sleep state mshv: Add definitions for MSHV sleep state configuration mshv: Add support for movable memory regions mshv: Add refcount and locking to mem regions mshv: Fix huge page handling in memory region traversal mshv: Move region management to mshv_regions.c mshv: Centralize guest memory region destruction mshv: Refactor and rename memory region handling functions mshv: adjust interrupt control structure for ARM64 Drivers: hv: use kmalloc_array() instead of kmalloc() mshv: Add ioctl for self targeted passthrough hvcalls Drivers: hv: Introduce mshv_vtl driver Drivers: hv: Export some symbols for mshv_vtl static_call: allow using STATIC_CALL_TRAMP_STR() from assembly mshv: Extend create partition ioctl to support cpu features mshv: Allow mappings that overlap in uaddr mshv: Fix create memory region overlap check mshv: add WQ_PERCPU to alloc_workqueue users Drivers: hv: Use kmalloc_array() instead of kmalloc() ...
2025-12-05Merge tag 'soc-drivers-6.19' of ↵Linus Torvalds1-5/+9
git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc Pull SoC driver updates from Arnd Bergmann: "This is the first half of the driver changes: - A treewide interface change to the "syscore" operations for power management, as a preparation for future Tegra specific changes - Reset controller updates with added drivers for LAN969x, eic770 and RZ/G3S SoCs - Protection of system controller registers on Renesas and Google SoCs, to prevent trivially triggering a system crash from e.g. debugfs access - soc_device identification updates on Nvidia, Exynos and Mediatek - debugfs support in the ST STM32 firewall driver - Minor updates for SoC drivers on AMD/Xilinx, Renesas, Allwinner, TI - Cleanups for memory controller support on Nvidia and Renesas" * tag 'soc-drivers-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (114 commits) memory: tegra186-emc: Fix missing put_bpmp Documentation: reset: Remove reset_controller_add_lookup() reset: fix BIT macro reference reset: rzg2l-usbphy-ctrl: Fix a NULL vs IS_ERR() bug in probe reset: th1520: Support reset controllers in more subsystems reset: th1520: Prepare for supporting multiple controllers dt-bindings: reset: thead,th1520-reset: Add controllers for more subsys dt-bindings: reset: thead,th1520-reset: Remove non-VO-subsystem resets reset: remove legacy reset lookup code clk: davinci: psc: drop unused reset lookup reset: rzg2l-usbphy-ctrl: Add support for RZ/G3S SoC reset: rzg2l-usbphy-ctrl: Add support for USB PWRRDY dt-bindings: reset: renesas,rzg2l-usbphy-ctrl: Document RZ/G3S support reset: eswin: Add eic7700 reset driver dt-bindings: reset: eswin: Documentation for eic7700 SoC reset: sparx5: add LAN969x support dt-bindings: reset: microchip: Add LAN969x support soc: rockchip: grf: Add select correct PWM implementation on RK3368 soc/tegra: pmc: Add USB wake events for Tegra234 amba: tegra-ahb: Fix device leak on SMMU enable ...
2025-12-05mshv: Cleanly shutdown root partition with MSHVPraveen K Paladugu1-0/+21
Root partitions running on MSHV currently attempt ACPI power-off, which MSHV intercepts and triggers a Machine Check Exception (MCE), leading to a kernel panic. Root partitions panic with a trace similar to: [ 81.306348] reboot: Power down [ 81.314709] mce: [Hardware Error]: CPU 0: Machine Check Exception: 4 Bank 0: b2000000c0060001 [ 81.314711] mce: [Hardware Error]: TSC 3b8cb60a66 PPIN 11d98332458e4ea9 [ 81.314713] mce: [Hardware Error]: PROCESSOR 0:606a6 TIME 1759339405 SOCKET 0 APIC 0 microcode ffffffff [ 81.314715] mce: [Hardware Error]: Run the above through 'mcelog --ascii' [ 81.314716] mce: [Hardware Error]: Machine check: Processor context corrupt [ 81.314717] Kernel panic - not syncing: Fatal machine check To avoid this, configure the sleep state in the hypervisor and invoke the HVCALL_ENTER_SLEEP_STATE hypercall as the final step in the shutdown sequence. This ensures a clean and safe shutdown of the root partition. Signed-off-by: Praveen K Paladugu <prapal@linux.microsoft.com> Co-developed-by: Anatol Belski <anbelski@linux.microsoft.com> Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com> Reviewed-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com> Acked-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-12-05mshv: Use reboot notifier to configure sleep statePraveen K Paladugu1-0/+78
Configure sleep state information from ACPI in MSHV hypervisor using a reboot notifier. This data allows the hypervisor to correctly power off the host during shutdown. Signed-off-by: Praveen K Paladugu <prapal@linux.microsoft.com> Co-developed-by: Anatol Belski <anbelski@linux.microsoft.com> Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com> Reviewed-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com> Reviewed-by: Stansialv Kinsburskii <skinsburskii@linux.miscrosoft.com> Acked-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-12-05mshv: Add support for movable memory regionsStanislav Kinsburskii4-36/+346
Introduce support for movable memory regions in the Hyper-V root partition driver to improve memory management flexibility and enable advanced use cases such as dynamic memory remapping. Mirror the address space between the Linux root partition and guest VMs using HMM. The root partition owns the memory, while guest VMs act as devices with page tables managed via hypercalls. MSHV handles VP intercepts by invoking hmm_range_fault() and updating SLAT entries. When memory is reclaimed, HMM invalidates the relevant regions, prompting MSHV to clear SLAT entries; guest VMs will fault again on access. Integrate mmu_interval_notifier for movable regions, implement handlers for HMM faults and memory invalidation, and update memory region mapping logic to support movable regions. While MMU notifiers are commonly used in virtualization drivers, this implementation leverages HMM (Heterogeneous Memory Management) for its specialized functionality. HMM provides a framework for mirroring, invalidation, and fault handling, reducing boilerplate and improving maintainability compared to generic MMU notifiers. Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-12-05mshv: Add refcount and locking to mem regionsStanislav Kinsburskii3-12/+45
Introduce kref-based reference counting and spinlock protection for memory regions in Hyper-V partition management. This change improves memory region lifecycle management and ensures thread-safe access to the region list. Previously, the regions list was protected by the partition mutex. However, this approach is too heavy for frequent fault and invalidation operations. Finer grained locking is now used to improve efficiency and concurrency. This is a precursor to supporting movable memory regions. Fault and invalidation handling for movable regions will require safe traversal of the region list and holding a region reference while performing invalidation or fault operations. Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-12-05mshv: Fix huge page handling in memory region traversalStanislav Kinsburskii2-31/+191
The previous code assumed that if a region's first page was huge, the entire region consisted of huge pages and stored this in a large_pages flag. This premise is incorrect not only for movable regions (where pages can be split and merged on invalidate callbacks or page faults), but even for pinned regions: THPs can be split and merged during allocation, so a large, pinned region may contain a mix of huge and regular pages. This change removes the large_pages flag and replaces region-wide assumptions with per-chunk inspection of the actual page size when mapping, unmapping, sharing, and unsharing. This makes huge page handling correct for mixed-page regions and avoids relying on stale metadata that can easily become invalid as memory is remapped. Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-12-05mshv: Move region management to mshv_regions.cStanislav Kinsburskii4-165/+198
Refactor memory region management functions from mshv_root_main.c into mshv_regions.c for better modularity and code organization. Adjust function calls and headers to use the new implementation. Improve maintainability and separation of concerns in the mshv_root module. Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-12-05mshv: Centralize guest memory region destructionStanislav Kinsburskii1-31/+34
Centralize guest memory region destruction to prevent resource leaks and inconsistent cleanup across unmap and partition destruction paths. Unify region removal, encrypted partition access recovery, and region invalidation to improve maintainability and reliability. Reduce code duplication and make future updates less error-prone by encapsulating cleanup logic in a single helper. Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-12-05mshv: Refactor and rename memory region handling functionsStanislav Kinsburskii1-44/+36
Simplify and unify memory region management to improve code clarity and reliability. Consolidate pinning and invalidation logic, adopt consistent naming, and remove redundant checks to reduce complexity. Enhance documentation and update call sites for maintainability. Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-12-05mshv: adjust interrupt control structure for ARM64Jinank Jain3-0/+16
Interrupt control structure (union hv_interupt_control) has different fields when it comes to x86 vs ARM64. Bring in the correct structure from HyperV header files and adjust the existing interrupt routing code accordingly. Signed-off-by: Jinank Jain <jinankjain@microsoft.com> Signed-off-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-12-05Drivers: hv: use kmalloc_array() instead of kmalloc()Gongwei Li1-1/+1
Replace kmalloc() with kmalloc_array() to prevent potential overflow, as recommended in Documentation/process/deprecated.rst. Signed-off-by: Gongwei Li <ligongwei@kylinos.cn> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-12-05mshv: Add ioctl for self targeted passthrough hvcallsAnirudh Rayabharam (Microsoft)1-9/+38
Allow MSHV_ROOT_HVCALL IOCTL on the /dev/mshv fd. This IOCTL would execute a passthrough hypercall targeting the root/parent partition i.e. HV_PARTITION_ID_SELF. This will be useful for the VMM to query things like supported synthetic processor features, supported VMM capabiliites etc. Since hypercalls targeting the host partition could potentially perform privileged operations, allow only a limited set of hypercalls. To begin with, allow only: HVCALL_GET_PARTITION_PROPERTY HVCALL_GET_PARTITION_PROPERTY_EX Signed-off-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-12-05Drivers: hv: Introduce mshv_vtl driverNaman Jain4-2/+1449
Provide an interface for Virtual Machine Monitor like OpenVMM and its use as OpenHCL paravisor to control VTL0 (Virtual trust Level). Expose devices and support IOCTLs for features like VTL creation, VTL0 memory management, context switch, making hypercalls, mapping VTL0 address space to VTL2 userspace, getting new VMBus messages and channel events in VTL2 etc. Co-developed-by: Roman Kisel <romank@linux.microsoft.com> Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Co-developed-by: Saurabh Sengar <ssengar@linux.microsoft.com> Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Naman Jain <namjain@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-12-02Merge tag 'core-rseq-2025-11-30' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull rseq updates from Thomas Gleixner: "A large overhaul of the restartable sequences and CID management: The recent enablement of RSEQ in glibc resulted in regressions which are caused by the related overhead. It turned out that the decision to invoke the exit to user work was not really a decision. More or less each context switch caused that. There is a long list of small issues which sums up nicely and results in a 3-4% regression in I/O benchmarks. The other detail which caused issues due to extra work in context switch and task migration is the CID (memory context ID) management. It also requires to use a task work to consolidate the CID space, which is executed in the context of an arbitrary task and results in sporadic uncontrolled exit latencies. The rewrite addresses this by: - Removing deprecated and long unsupported functionality - Moving the related data into dedicated data structures which are optimized for fast path processing. - Caching values so actual decisions can be made - Replacing the current implementation with a optimized inlined variant. - Separating fast and slow path for architectures which use the generic entry code, so that only fault and error handling goes into the TIF_NOTIFY_RESUME handler. - Rewriting the CID management so that it becomes mostly invisible in the context switch path. That moves the work of switching modes into the fork/exit path, which is a reasonable tradeoff. That work is only required when a process creates more threads than the cpuset it is allowed to run on or when enough threads exit after that. An artificial thread pool benchmarks which triggers this did not degrade, it actually improved significantly. The main effect in migration heavy scenarios is that runqueue lock held time and therefore contention goes down significantly" * tag 'core-rseq-2025-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits) sched/mmcid: Switch over to the new mechanism sched/mmcid: Implement deferred mode change irqwork: Move data struct to a types header sched/mmcid: Provide CID ownership mode fixup functions sched/mmcid: Provide new scheduler CID mechanism sched/mmcid: Introduce per task/CPU ownership infrastructure sched/mmcid: Serialize sched_mm_cid_fork()/exit() with a mutex sched/mmcid: Provide precomputed maximal value sched/mmcid: Move initialization out of line signal: Move MMCID exit out of sighand lock sched/mmcid: Convert mm CID mask to a bitmap cpumask: Cache num_possible_cpus() sched/mmcid: Use cpumask_weighted_or() cpumask: Introduce cpumask_weighted_or() sched/mmcid: Prevent pointless work in mm_update_cpus_allowed() sched/mmcid: Move scheduler code out of global header sched: Fixup whitespace damage sched/mmcid: Cacheline align MM CID storage sched/mmcid: Use proper data structures sched/mmcid: Revert the complex CID management ...
2025-11-28hv: convert mshv_ioctl_create_partition() to FD_ADD()Christian Brauner1-24/+6
Link: https://patch.msgid.link/20251123-work-fd-prepare-v4-39-b6efa1706cfd@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-15Drivers: hv: Export some symbols for mshv_vtlNaman Jain3-1/+7
MSHV_VTL driver is going to be introduced, which is supposed to provide interface for Virtual Machine Monitors (VMMs) to control Virtual Trust Level (VTL). Export the symbols needed to make it work (vmbus_isr, hv_context and hv_post_message). Co-developed-by: Roman Kisel <romank@linux.microsoft.com> Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Co-developed-by: Saurabh Sengar <ssengar@linux.microsoft.com> Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com> Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202506110544.q0NDMQVc-lkp@intel.com/ Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Naman Jain <namjain@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15mshv: Extend create partition ioctl to support cpu featuresMuminul Islam1-21/+97
The existing mshv create partition ioctl does not provide a way to specify which cpu features are enabled in the guest. Instead, it attempts to enable all features and those that are not supported are silently disabled by the hypervisor. This was done to reduce unnecessary complexity and is sufficient for many cases. However, new scenarios require fine-grained control over these features. Define a new mshv_create_partition_v2 structure which supports passing the disabled processor and xsave feature bits through to the create partition hypercall directly. Introduce a new flag MSHV_PT_BIT_CPU_AND_XSAVE_FEATURES which enables the new structure. If unset, the original mshv_create_partition struct is used, with the old behavior of enabling all features. Co-developed-by: Jinank Jain <jinankjain@microsoft.com> Signed-off-by: Jinank Jain <jinankjain@microsoft.com> Signed-off-by: Muminul Islam <muislam@microsoft.com> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15mshv: Allow mappings that overlap in uaddrMagnus Kulke1-6/+2
Currently the MSHV driver rejects mappings that would overlap in userspace. Some VMMs require the same memory to be mapped to different parts of the guest's address space, and so working around this restriction is difficult. The hypervisor itself doesn't prohibit mappings that overlap in uaddr, (really in SPA; system physical addresses), so supporting this in the driver doesn't require any extra work: only the checks need to be removed. Since no userspace code until now has been able to overlap regions in userspace, relaxing this constraint can't break any existing code. Signed-off-by: Magnus Kulke <magnuskulke@linux.microsoft.com> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15mshv: Fix create memory region overlap checkNuno Das Neves1-20/+11
The current check is incorrect; it only checks if the beginning or end of a region is within an existing region. This doesn't account for userspace specifying a region that begins before and ends after an existing region. Change the logic to a range intersection check against gfns and uaddrs for each region. Remove mshv_partition_region_by_uaddr() as it is no longer used. Fixes: 621191d709b1 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs") Reported-by: Michael Kelley <mhklinux@outlook.com> Closes: https://lore.kernel.org/linux-hyperv/SN6PR02MB41575BE0406D3AB22E1D7DB5D4C2A@SN6PR02MB4157.namprd02.prod.outlook.com/ Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15mshv: add WQ_PERCPU to alloc_workqueue usersMarco Crivellari1-1/+1
Currently if a user enqueues a work item using schedule_delayed_work() the used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to schedule_work() that is using system_wq and queue_work(), that makes use again of WORK_CPU_UNBOUND. This lack of consistency cannot be addressed without refactoring the API. alloc_workqueue() treats all queues as per-CPU by default, while unbound workqueues must opt-in via WQ_UNBOUND. This default is suboptimal: most workloads benefit from unbound queues, allowing the scheduler to place worker threads where they’re needed and reducing noise when CPUs are isolated. This continues the effort to refactor workqueue APIs, which began with the introduction of new workqueues and a new alloc_workqueue flag in: commit 128ea9f6ccfb ("workqueue: Add system_percpu_wq and system_dfl_wq") commit 930c2ea566af ("workqueue: Add new WQ_PERCPU flag") This change adds a new WQ_PERCPU flag to explicitly request alloc_workqueue() to be per-cpu when WQ_UNBOUND has not been specified. With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND), any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND must now use WQ_PERCPU. Once migration is complete, WQ_UNBOUND can be removed and unbound will become the implicit default. Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Marco Crivellari <marco.crivellari@suse.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15Drivers: hv: Use kmalloc_array() instead of kmalloc()Rahul Kumar1-1/+1
Documentation/process/deprecated.rst recommends against the use of kmalloc with dynamic size calculations due to the risk of overflow and smaller allocation being made than the caller was expecting. Replace kmalloc() with kmalloc_array() in hv_common.c to make the intended allocation size clearer and avoid potential overflow issues. The number of pages (pgcount) is bounded, so overflow is not a practical concern here. However, using kmalloc_array() better reflects the intent to allocate an array and improves consistency with other allocations. No functional change intended. Signed-off-by: Rahul Kumar <rk0006818@gmail.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15Drivers: hv: Resolve ambiguity in hypervisor version logStanislav Kinsburskii1-2/+2
Update the log message in hv_common_init to explicitly state that the reported version is for the Microsoft Hypervisor, not the host OS. Previously, this message was accurate for guests running on Windows hosts, where the host and hypervisor versions matched. With support for Linux hosts running the Hyper-V hypervisor, the host OS and hypervisor versions may differ. This change avoids confusion by making it clear that the version refers to the Microsoft Hypervisor regardless of the host operating system. Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15Drivers: hv: fix missing kernel-doc description for 'size' in request_arr_init()Kriish Sharma1-1/+1
Add missing kernel-doc entry for the @size parameter in request_arr_init(), fixing the following documentation warning reported by the kernel test robot and detected via kernel-doc: Warning: drivers/hv/channel.c:595 function parameter 'size' not described in 'request_arr_init' Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202503021934.wH1BERla-lkp@intel.com Signed-off-by: Kriish Sharma <kriish.sharma2006@gmail.com> Reviewed-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15mshv: Introduce new hypercall to map stats page for L1VH partitionsJinank Jain3-20/+107
Introduce HVCALL_MAP_STATS_PAGE2 which provides a map location (GPFN) to map the stats to. This hypercall is required for L1VH partitions, depending on the hypervisor version. This uses the same check as the state page map location; mshv_use_overlay_gpfn(). Add mshv_map_vp_state_page() helpers to use this new hypercall or the old one depending on availability. For unmapping, the original HVCALL_UNMAP_STATS_PAGE works for both cases. Signed-off-by: Jinank Jain <jinankjain@linux.microsoft.com> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15mshv: Allocate vp state page for HVCALL_MAP_VP_STATE_PAGE on L1VHJinank Jain3-50/+101
Introduce mshv_use_overlay_gpfn() to check if a page needs to be allocated and passed to the hypervisor to map VP state pages. This is only needed on L1VH, and only on some (newer) versions of the hypervisor, hence the need to check vmm_capabilities. Introduce functions hv_map/unmap_vp_state_page() to handle the allocation and freeing. Signed-off-by: Jinank Jain <jinankjain@linux.microsoft.com> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Praveen K Paladugu <prapal@linux.microsoft.com> Reviewed-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Anirudh Rayabharam <anirudh@anirudhrb.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15mshv: Get the vmm capabilities offered by the hypervisorPurna Pavan Chandra Aekkaladevi2-0/+19
Some hypervisor APIs are gated by feature bits in the "vmm capabilities" partition property. Store the capabilities on mshv_root module init, using HVCALL_GET_PARTITION_PROPERTY_EX. This is not supported on all hypervisors. In that case, just set the capabilities to 0 and proceed as normal. Signed-off-by: Purna Pavan Chandra Aekkaladevi <paekkaladevi@linux.microsoft.com> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Praveen K Paladugu <prapal@linux.microsoft.com> Reviewed-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15mshv: Add the HVCALL_GET_PARTITION_PROPERTY_EX hypercallPurna Pavan Chandra Aekkaladevi2-0/+33
This hypercall can be used to fetch extended properties of a partition. Extended properties are properties with values larger than a u64. Some of these also need additional input arguments. Add helper function for using the hypercall in the mshv_root driver. Signed-off-by: Purna Pavan Chandra Aekkaladevi <paekkaladevi@linux.microsoft.com> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Anirudh Rayabharam <anirudh@anirudhrb.com> Reviewed-by: Praveen K Paladugu <prapal@linux.microsoft.com> Reviewed-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15mshv: Only map vp->vp_stats_pages if on root schedulerNuno Das Neves1-4/+8
This mapping is only used for checking if the dispatch thread is blocked. This is only relevant for the root scheduler, so check the scheduler type to determine whether to map/unmap these pages, instead of the current check, which is incorrect. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Anirudh Rayabharam <anirudh@anirudhrb.com> Reviewed-by: Praveen K Paladugu <prapal@linux.microsoft.com> Reviewed-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Acked-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15Drivers: hv: Support establishing the confidential VMBus connectionRoman Kisel1-62/+106
To establish the confidential VMBus connection the CoCo VM, the guest first checks on the confidential VMBus availability, and then proceeds to initializing the communication stack. Implement that in the VMBus driver initialization. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15Drivers: hv: Set the default VMBus version to 6.0Roman Kisel1-1/+2
The confidential VMBus is supported by the protocol version 6.0 onwards. Attempt to establish the VMBus 6.0 connection thus enabling the confidential VMBus features when available. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15Drivers: hv: Support confidential VMBus channelsRoman Kisel2-0/+22
To make use of Confidential VMBus channels, initialize the co_ring_buffers and co_external_memory fields of the channel structure. Advertise support upon negotiating the version and compute values for those fields and initialize them. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15Drivers: hv: Free msginfo when the buffer fails to decryptRoman Kisel1-6/+18
The early failure path in __vmbus_establish_gpadl() doesn't deallocate msginfo if the buffer fails to decrypt. Fix the leak by breaking out the cleanup code into a separate function and calling it where required. Fixes: d4dccf353db80 ("Drivers: hv: vmbus: Mark vmbus ring buffer visible to host in Isolation VM") Reported-by: Michael Kelley <mkhlinux@outlook.com> Closes: https://lore.kernel.org/linux-hyperv/SN6PR02MB41573796F9787F67E0E97049D472A@SN6PR02MB4157.namprd02.prod.outlook.com Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15Drivers: hv: Allocate encrypted buffers when requestedRoman Kisel3-23/+34
Confidential VMBus is built around using buffers not shared with the host. Support allocating encrypted buffers when requested. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15Drivers: hv: Functions for setting up and tearing down the paravisor SynICRoman Kisel1-12/+126
The confidential VMBus runs with the paravisor SynIC and requires configuring it with the paravisor. Add the functions for configuring the paravisor SynIC. Update overall SynIC initialization logic to initialize the SynIC if it is present. Finally, break out SynIC interrupt enable/disable code into separate functions so that SynIC interrupts can be enabled or disabled via the paravisor instead of the hypervisor if the paravisor SynIC is present. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15Drivers: hv: Rename the SynIC enable and disable routinesRoman Kisel4-11/+12
The confidential VMBus requires support for the both hypervisor facing SynIC and the paravisor one. Rename the functions that enable and disable SynIC with the hypervisor. No functional changes. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15Drivers: hv: Check message and event pages for non-NULL before iounmap()Roman Kisel1-4/+8
It might happen that some hyp SynIC pages aren't allocated. Check for that and only then call iounmap(). Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15Drivers: hv: remove stale commentRoman Kisel1-5/+1
The comment about the x2v shim is ancient and long since incorrect. Remove the incorrect comment. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15Drivers: hv: Post messages through the confidential VMBus if availableRoman Kisel1-1/+10
When the confidential VMBus is available, the guest should post messages to the paravisor. Update hv_post_message() to post messages to the paravisor rather than through GHCB or TD calls. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15Drivers: hv: Allocate the paravisor SynIC pages when requiredRoman Kisel2-90/+112
Confidential VMBus requires interacting with two SynICs -- one provided by the host hypervisor, and one provided by the paravisor. Each SynIC requires its own message and event pages. Refactor and extend the existing code to add allocating and freeing the message and event pages for the paravisor SynIC when it is present. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15Drivers: hv: Rename fields for SynIC message and event pagesRoman Kisel6-45/+45
Confidential VMBus requires interacting with two SynICs -- one provided by the host hypervisor, and one provided by the paravisor. Each SynIC requires its own message and event pages. Rename the existing host-accessible SynIC message and event pages with the "hyp_" prefix to clearly distinguish them from the paravisor ones. The field name is also changed in mshv_root.* for consistency. No functional changes. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15arch/x86: mshyperv: Trap on access for some synthetic MSRsRoman Kisel1-0/+5
hv_set_non_nested_msr() has special handling for SINT MSRs when a paravisor is present. In addition to updating the MSR on the host, the mirror MSR in the paravisor is updated, including with the proxy bit. But with Confidential VMBus, the proxy bit must not be used, so add a special case to skip it. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Alok Tiwari <alok.a.tiwari@oracle.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15arch: hyperv: Get/set SynIC synth.registers via paravisorRoman Kisel2-0/+55
The existing Hyper-V wrappers for getting and setting MSRs are hv_get/set_msr(). Via hv_get/set_non_nested_msr(), they detect when running in a CoCo VM with a paravisor, and use the TDX or SNP guest-host communication protocol to bypass the paravisor and go directly to the host hypervisor for SynIC MSRs. The "set" function also implements the required special handling for the SINT MSRs. Provide functions that allow manipulating the SynIC registers through the paravisor. Move vmbus_signal_eom() to a more appropriate location (which also avoids breaking KVM). Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Alok Tiwari <alok.a.tiwari@oracle.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15Drivers: hv: VMBus protocol version 6.0Roman Kisel2-0/+14
The confidential VMBus is supported starting from the protocol version 6.0 onwards. Provide the required definitions. No functional changes. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Alok Tiwari <alok.a.tiwari@oracle.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15drivers: hv: Allow vmbus message synic interrupt injected from Hyper-VTianyu Lan2-0/+7
When Secure AVIC is enabled, VMBus driver should call x2apic Secure AVIC interface to allow Hyper-V to inject VMBus message interrupt. Reviewed-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com> Signed-off-by: Tianyu Lan <tiala@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15mshv: Fix deposit memory in MSHV_ROOT_HVCALLNuno Das Neves1-27/+29
When the MSHV_ROOT_HVCALL ioctl is executing a hypercall, and gets HV_STATUS_INSUFFICIENT_MEMORY, it deposits memory and then returns -EAGAIN to userspace. The expectation is that the VMM will retry. However, some VMM code in the wild doesn't do this and simply fails. Rather than force the VMM to retry, change the ioctl to deposit memory on demand and immediately retry the hypercall as is done with all the other hypercall helper functions. In addition to making the ioctl easier to use, removing the need for multiple syscalls improves performance. There is a complication: unlike the other hypercall helper functions, in MSHV_ROOT_HVCALL the input is opaque to the kernel. This is problematic for rep hypercalls, because the next part of the input list can't be copied on each loop after depositing pages (this was the original reason for returning -EAGAIN in this case). Introduce hv_do_rep_hypercall_ex(), which adds a 'rep_start' parameter. This solves the issue, allowing the deposit loop in MSHV_ROOT_HVCALL to restart a rep hypercall after depositing pages partway through. Fixes: 621191d709b1 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs") Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15mshv: Fix VpRootDispatchThreadBlocked valueNuno Das Neves1-1/+1
This value in the VP stats page is used to track if the VP can be dispatched for execution when there are no fast interrupts injected. The original value of 201 was used in a version of the hypervisor which did not ship. It was subsequently changed to 202 so that is the correct value. Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-14syscore: Pass context data to callbacksThierry Reding1-5/+9
Several drivers can benefit from registering per-instance data along with the syscore operations. To achieve this, move the modifiable fields out of the syscore_ops structure and into a separate struct syscore that can be registered with the framework. Add a void * driver data field for drivers to store contextual data that will be passed to the syscore ops. Acked-by: Rafael J. Wysocki (Intel) <rafael@kernel.org> Signed-off-by: Thierry Reding <treding@nvidia.com>
2025-11-04rseq, virt: Retrigger RSEQ after vcpu_run()Thomas Gleixner1-0/+3
Hypervisors invoke resume_user_mode_work() before entering the guest, which clears TIF_NOTIFY_RESUME. The @regs argument is NULL as there is no user space context available to them, so the rseq notify handler skips inspecting the critical section, but updates the CPU/MM CID values unconditionally so that the eventual pending rseq event is not lost on the way to user space. This is a pointless exercise as the task might be rescheduled before actually returning to user space and it creates unnecessary work in the vcpu_run() loops. It's way more efficient to ignore that invocation based on @regs == NULL and let the hypervisors re-raise TIF_NOTIFY_RESUME after returning from the vcpu_run() loop before returning from the ioctl(). This ensures that a pending RSEQ update is not lost and the IDs are updated before returning to user space. Once the RSEQ handling is decoupled from TIF_NOTIFY_RESUME, this turns into a NOOP. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Sean Christopherson <seanjc@google.com> Link: https://patch.msgid.link/20251027084306.399495855@linutronix.de
2025-10-01Drivers: hv: Make CONFIG_HYPERV boolMukesh Rathor2-2/+2
With CONFIG_HYPERV and CONFIG_HYPERV_VMBUS separated, change CONFIG_HYPERV to bool from tristate. CONFIG_HYPERV now becomes the core Hyper-V hypervisor support, such as hypercalls, clocks/timers, Confidential Computing setup, PCI passthru, etc. that doesn't involve VMBus or VMBus devices. Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-10-01Drivers: hv: Add CONFIG_HYPERV_VMBUS optionMukesh Rathor2-3/+10
At present VMBus driver is hinged off of CONFIG_HYPERV which entails lot of builtin code and encompasses too much. It's not always clear what depends on builtin hv code and what depends on VMBus. Setting CONFIG_HYPERV as a module and fudging the Makefile to switch to builtin adds even more confusion. VMBus is an independent module and should have its own config option. Also, there are scenarios like baremetal dom0/root where support is built in with CONFIG_HYPERV but without VMBus. Lastly, there are more features coming down that use CONFIG_HYPERV and add more dependencies on it. So, create a fine grained HYPERV_VMBUS option and update Kconfigs for dependency on VMBus. Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> # drivers/pci Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-09-30Drivers: hv: vmbus: Fix typos in vmbus_drv.cAlok Tiwari1-2/+2
Fix two minor typos in vmbus_drv.c: - Correct "reponsible" -> "responsible" in a comment. - Add missing newline in pr_err() message ("channeln" -> "channel\n"). These are cosmetic changes only and do not affect functionality. Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-09-30Drivers: hv: vmbus: Fix sysfs output format for ring buffer indexAlok Tiwari1-2/+2
The sysfs attributes out_read_index and out_write_index in vmbus_drv.c currently use %d to print outbound.current_read_index and outbound.current_write_index. These fields are u32 values, so printing them with %d (signed) is not logically correct. Update the format specifier to %u to correctly match their type. No functional change, only fixes the sysfs output format. Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-09-30Drivers: hv: vmbus: Clean up sscanf format specifier in target_cpu_store()Alok Tiwari1-1/+1
The target_cpu_store() function parses the target CPU from the sysfs buffer using sscanf(). The format string currently uses "%uu", which is redundant. The compiler ignores the extra "u", so there is no incorrect parsing at runtime. Update the format string to use "%u" for clarity and consistency. Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-09-30x86/hyperv: Switch to msi_create_parent_irq_domain()Nam Cao1-0/+1
Move away from the legacy MSI domain setup, switch to use msi_create_parent_irq_domain(). While doing the conversion, I noticed that hv_irq_compose_msi_msg() is doing more than it is supposed to (composing message content). The interrupt allocation bits should be moved into hv_msi_domain_alloc(). However, I have no hardware to test this change, therefore I leave a TODO note. Signed-off-by: Nam Cao <namcao@linutronix.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-09-30mshv: Use common "entry virt" APIs to do work in root before running guestSean Christopherson4-50/+7
Use the kernel's common "entry virt" APIs to handle pending work prior to (re)entering guest mode, now that the virt APIs don't have a superfluous dependency on KVM. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Tested-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-09-30mshv: Handle NEED_RESCHED_LAZY before transferring to guestSean Christopherson2-2/+3
Check for NEED_RESCHED_LAZY, not just NEED_RESCHED, prior to transferring control to a guest. Failure to check for lazy resched can unnecessarily delay rescheduling until the next tick when using a lazy preemption model. Note, ideally both the checking and processing of TIF bits would be handled in common code, to avoid having to keep three separate paths synchronized, but defer such cleanups to the future to keep the fix as standalone as possible. Cc: Nuno Das Neves <nunodasneves@linux.microsoft.com> Cc: Mukesh R <mrathor@linux.microsoft.com> Fixes: 621191d709b1 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs") Signed-off-by: Sean Christopherson <seanjc@google.com> Tested-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-09-08Drivers: hv: Simplify data structures for VMBus channel close messageMichael Kelley1-1/+1
struct vmbus_close_msg is used for sending the VMBus channel close message. It contains a struct vmbus_channel_msginfo, which has a flex array member at the end. The latter's presence in the middle of struct vmbus_close_msg causes warnings when built with -Wflex-array-member-not-at-end. But the struct vmbus_channel_msginfo is unused because the Hyper-V host does not send a response to the channel close message. So remove the struct vmbus_channel_msginfo. Then, since the only remaining field is struct vmbus_channel_close_channel, also remove the containing struct vmbus_close_msg and directly use struct vmbus_channel_close_channel. Besides eliminating unnecessary complexity, these changes resolve the -Wflex-array-member-not-at-end warnings. Signed-off-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-09-08Drivers: hv: util: Cosmetic changes for hv_utils_transport.cAbhishek Tiwari1-5/+5
Fix issues reported by checkpatch.pl script for hv_utils_transport.c file - Update pr_warn() calls to use __func__ for consistent logging context. - else should follow close brace '}' No functional changes intended. Signed-off-by: Abhishek Tiwari <abhitiwari@linux.microsoft.com> Reviewed-by: Naman Jain <namjain@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-09-08mshv: Add support for a new parent partition configurationNuno Das Neves2-22/+26
Detect booting as an "L1VH" partition. This is a new scenario very similar to root partition where the mshv_root driver can be used to create and manage guest partitions. It mostly works the same as root partition, but there are some differences in how various features are handled. hv_l1vh_partition() is introduced to handle these cases. Add hv_parent_partition() which returns true for either case, replacing some hv_root_partition() checks. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Acked-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-07-30Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-0/+8
Pull kvm updates from Paolo Bonzini: "ARM: - Host driver for GICv5, the next generation interrupt controller for arm64, including support for interrupt routing, MSIs, interrupt translation and wired interrupts - Use FEAT_GCIE_LEGACY on GICv5 systems to virtualize GICv3 VMs on GICv5 hardware, leveraging the legacy VGIC interface - Userspace control of the 'nASSGIcap' GICv3 feature, allowing userspace to disable support for SGIs w/o an active state on hardware that previously advertised it unconditionally - Map supporting endpoints with cacheable memory attributes on systems with FEAT_S2FWB and DIC where KVM no longer needs to perform cache maintenance on the address range - Nested support for FEAT_RAS and FEAT_DoubleFault2, allowing the guest hypervisor to inject external aborts into an L2 VM and take traps of masked external aborts to the hypervisor - Convert more system register sanitization to the config-driven implementation - Fixes to the visibility of EL2 registers, namely making VGICv3 system registers accessible through the VGIC device instead of the ONE_REG vCPU ioctls - Various cleanups and minor fixes LoongArch: - Add stat information for in-kernel irqchip - Add tracepoints for CPUCFG and CSR emulation exits - Enhance in-kernel irqchip emulation - Various cleanups RISC-V: - Enable ring-based dirty memory tracking - Improve perf kvm stat to report interrupt events - Delegate illegal instruction trap to VS-mode - MMU improvements related to upcoming nested virtualization s390x - Fixes x86: - Add CONFIG_KVM_IOAPIC for x86 to allow disabling support for I/O APIC, PIC, and PIT emulation at compile time - Share device posted IRQ code between SVM and VMX and harden it against bugs and runtime errors - Use vcpu_idx, not vcpu_id, for GA log tag/metadata, to make lookups O(1) instead of O(n) - For MMIO stale data mitigation, track whether or not a vCPU has access to (host) MMIO based on whether the page tables have MMIO pfns mapped; using VFIO is prone to false negatives - Rework the MSR interception code so that the SVM and VMX APIs are more or less identical - Recalculate all MSR intercepts from scratch on MSR filter changes, instead of maintaining shadow bitmaps - Advertise support for LKGS (Load Kernel GS base), a new instruction that's loosely related to FRED, but is supported and enumerated independently - Fix a user-triggerable WARN that syzkaller found by setting the vCPU in INIT_RECEIVED state (aka wait-for-SIPI), and then putting the vCPU into VMX Root Mode (post-VMXON). Trying to detect every possible path leading to architecturally forbidden states is hard and even risks breaking userspace (if it goes from valid to valid state but passes through invalid states), so just wait until KVM_RUN to detect that the vCPU state isn't allowed - Add KVM_X86_DISABLE_EXITS_APERFMPERF to allow disabling interception of APERF/MPERF reads, so that a "properly" configured VM can access APERF/MPERF. This has many caveats (APERF/MPERF cannot be zeroed on vCPU creation or saved/restored on suspend and resume, or preserved over thread migration let alone VM migration) but can be useful whenever you're interested in letting Linux guests see the effective physical CPU frequency in /proc/cpuinfo - Reject KVM_SET_TSC_KHZ for vm file descriptors if vCPUs have been created, as there's no known use case for changing the default frequency for other VM types and it goes counter to the very reason why the ioctl was added to the vm file descriptor. And also, there would be no way to make it work for confidential VMs with a "secure" TSC, so kill two birds with one stone - Dynamically allocation the shadow MMU's hashed page list, and defer allocating the hashed list until it's actually needed (the TDP MMU doesn't use the list) - Extract many of KVM's helpers for accessing architectural local APIC state to common x86 so that they can be shared by guest-side code for Secure AVIC - Various cleanups and fixes x86 (Intel): - Preserve the host's DEBUGCTL.FREEZE_IN_SMM when running the guest. Failure to honor FREEZE_IN_SMM can leak host state into guests - Explicitly check vmcs12.GUEST_DEBUGCTL on nested VM-Enter to prevent L1 from running L2 with features that KVM doesn't support, e.g. BTF x86 (AMD): - WARN and reject loading kvm-amd.ko instead of panicking the kernel if the nested SVM MSRPM offsets tracker can't handle an MSR (which is pretty much a static condition and therefore should never happen, but still) - Fix a variety of flaws and bugs in the AVIC device posted IRQ code - Inhibit AVIC if a vCPU's ID is too big (relative to what hardware supports) instead of rejecting vCPU creation - Extend enable_ipiv module param support to SVM, by simply leaving IsRunning clear in the vCPU's physical ID table entry - Disable IPI virtualization, via enable_ipiv, if the CPU is affected by erratum #1235, to allow (safely) enabling AVIC on such CPUs - Request GA Log interrupts if and only if the target vCPU is blocking, i.e. only if KVM needs a notification in order to wake the vCPU - Intercept SPEC_CTRL on AMD if the MSR shouldn't exist according to the vCPU's CPUID model - Accept any SNP policy that is accepted by the firmware with respect to SMT and single-socket restrictions. An incompatible policy doesn't put the kernel at risk in any way, so there's no reason for KVM to care - Drop a superfluous WBINVD (on all CPUs!) when destroying a VM and use WBNOINVD instead of WBINVD when possible for SEV cache maintenance - When reclaiming memory from an SEV guest, only do cache flushes on CPUs that have ever run a vCPU for the guest, i.e. don't flush the caches for CPUs that can't possibly have cache lines with dirty, encrypted data Generic: - Rework irqbypass to track/match producers and consumers via an xarray instead of a linked list. Using a linked list leads to O(n^2) insertion times, which is hugely problematic for use cases that create large numbers of VMs. Such use cases typically don't actually use irqbypass, but eliminating the pointless registration is a future problem to solve as it likely requires new uAPI - Track irqbypass's "token" as "struct eventfd_ctx *" instead of a "void *", to avoid making a simple concept unnecessarily difficult to understand - Decouple device posted IRQs from VFIO device assignment, as binding a VM to a VFIO group is not a requirement for enabling device posted IRQs - Clean up and document/comment the irqfd assignment code - Disallow binding multiple irqfds to an eventfd with a priority waiter, i.e. ensure an eventfd is bound to at most one irqfd through the entire host, and add a selftest to verify eventfd:irqfd bindings are globally unique - Add a tracepoint for KVM_SET_MEMORY_ATTRIBUTES to help debug issues related to private <=> shared memory conversions - Drop guest_memfd's .getattr() implementation as the VFS layer will call generic_fillattr() if inode_operations.getattr is NULL - Fix issues with dirty ring harvesting where KVM doesn't bound the processing of entries in any way, which allows userspace to keep KVM in a tight loop indefinitely - Kill off kvm_arch_{start,end}_assignment() and x86's associated tracking, now that KVM no longer uses assigned_device_count as a heuristic for either irqbypass usage or MDS mitigation Selftests: - Fix a comment typo - Verify KVM is loaded when getting any KVM module param so that attempting to run a selftest without kvm.ko loaded results in a SKIP message about KVM not being loaded/enabled (versus some random parameter not existing) - Skip tests that hit EACCES when attempting to access a file, and print a "Root required?" help message. In most cases, the test just needs to be run with elevated permissions" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (340 commits) Documentation: KVM: Use unordered list for pre-init VGIC registers RISC-V: KVM: Avoid re-acquiring memslot in kvm_riscv_gstage_map() RISC-V: KVM: Use find_vma_intersection() to search for intersecting VMAs RISC-V: perf/kvm: Add reporting of interrupt events RISC-V: KVM: Enable ring-based dirty memory tracking RISC-V: KVM: Fix inclusion of Smnpm in the guest ISA bitmap RISC-V: KVM: Delegate illegal instruction fault to VS mode RISC-V: KVM: Pass VMID as parameter to kvm_riscv_hfence_xyz() APIs RISC-V: KVM: Factor-out g-stage page table management RISC-V: KVM: Add vmid field to struct kvm_riscv_hfence RISC-V: KVM: Introduce struct kvm_gstage_mapping RISC-V: KVM: Factor-out MMU related declarations into separate headers RISC-V: KVM: Use ncsr_xyz() in kvm_riscv_vcpu_trap_redirect() RISC-V: KVM: Implement kvm_arch_flush_remote_tlbs_range() RISC-V: KVM: Don't flush TLB when PTE is unchanged RISC-V: KVM: Replace KVM_REQ_HFENCE_GVMA_VMID_ALL with KVM_REQ_TLB_FLUSH RISC-V: KVM: Rename and move kvm_riscv_local_tlb_sanitize() RISC-V: KVM: Drop the return value of kvm_riscv_vcpu_aia_init() RISC-V: KVM: Check kvm_riscv_vcpu_alloc_vector_context() return value KVM: arm64: selftests: Add FEAT_RAS EL2 registers to get-reg-list ...
2025-07-29Merge tag 'kvm-x86-irqs-6.17' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini1-0/+8
KVM IRQ changes for 6.17 - Rework irqbypass to track/match producers and consumers via an xarray instead of a linked list. Using a linked list leads to O(n^2) insertion times, which is hugely problematic for use cases that create large numbers of VMs. Such use cases typically don't actually use irqbypass, but eliminating the pointless registration is a future problem to solve as it likely requires new uAPI. - Track irqbypass's "token" as "struct eventfd_ctx *" instead of a "void *", to avoid making a simple concept unnecessarily difficult to understand. - Add CONFIG_KVM_IOAPIC for x86 to allow disabling support for I/O APIC, PIC, and PIT emulation at compile time. - Drop x86's irq_comm.c, and move a pile of IRQ related code into irq.c. - Fix a variety of flaws and bugs in the AVIC device posted IRQ code. - Inhibited AVIC if a vCPU's ID is too big (relative to what hardware supports) instead of rejecting vCPU creation. - Extend enable_ipiv module param support to SVM, by simply leaving IsRunning clear in the vCPU's physical ID table entry. - Disable IPI virtualization, via enable_ipiv, if the CPU is affected by erratum #1235, to allow (safely) enabling AVIC on such CPUs. - Dedup x86's device posted IRQ code, as the vast majority of functionality can be shared verbatime between SVM and VMX. - Harden the device posted IRQ code against bugs and runtime errors. - Use vcpu_idx, not vcpu_id, for GA log tag/metadata, to make lookups O(1) instead of O(n). - Generate GA Log interrupts if and only if the target vCPU is blocking, i.e. only if KVM needs a notification in order to wake the vCPU. - Decouple device posted IRQs from VFIO device assignment, as binding a VM to a VFIO group is not a requirement for enabling device posted IRQs. - Clean up and document/comment the irqfd assignment code. - Disallow binding multiple irqfds to an eventfd with a priority waiter, i.e. ensure an eventfd is bound to at most one irqfd through the entire host, and add a selftest to verify eventfd:irqfd bindings are globally unique.
2025-07-28Merge tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-11/+3
Pull CLASS(fd) update from Al Viro: "A missing bit of commit 66635b077624 ("assorted variants of irqfd setup: convert to CLASS(fd)") from a year ago. mshv_eventfd would've been covered by that, but it had forked slightly before that series and got merged into mainline later" * tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: mshv_eventfd: convert to CLASS(fd)
2025-07-16mshv_eventfd: convert to CLASS(fd)Al Viro1-11/+3
similar to 66635b077624 ("assorted variants of irqfd setup: convert to CLASS(fd)") a year ago... Acked-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-07-15Drivers: hv: Use nested hypercall for post message and signal eventNuno Das Neves2-3/+8
When running nested, these hypercalls must be sent to the L0 hypervisor or VMBus will fail. Remove hv_do_nested_hypercall() and hv_do_fast_nested_hypercall8() altogether and open-code these cases, since there are only 2 and all they do is add the nested bit. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1752261532-7225-2-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1752261532-7225-2-git-send-email-nunodasneves@linux.microsoft.com>
2025-07-09Drivers: hv: Fix warnings for missing export.h header inclusionNaman Jain6-0/+6
Fix below warning in Hyper-V drivers that comes when kernel is compiled with W=1 option. Include export.h in driver files to fix it. * warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing Signed-off-by: Naman Jain <namjain@linux.microsoft.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com> Link: https://lore.kernel.org/r/20250611100459.92900-2-namjain@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250611100459.92900-2-namjain@linux.microsoft.com>
2025-07-09Drivers: hv: Fix the check for HYPERVISOR_CALLBACK_VECTORNaman Jain1-4/+5
__is_defined(HYPERVISOR_CALLBACK_VECTOR) would return 1, only if HYPERVISOR_CALLBACK_VECTOR macro is defined as 1. However its value is 0xf3 and this leads to __is_defined() returning 0. The expectation was to just check whether this MACRO is defined or not and get 1 if it's defined. Replace __is_defined with #ifdef blocks instead to fix it. Fixes: 1dc5df133b98 ("Drivers: hv: vmbus: Get the IRQ number from DeviceTree") Cc: stable@kernel.org Signed-off-by: Naman Jain <namjain@linux.microsoft.com> Reviewed-by: Roman Kisel <romank@linux.microsoft.com> Link: https://lore.kernel.org/r/20250707084322.1763-1-namjain@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250707084322.1763-1-namjain@linux.microsoft.com>
2025-07-09Drivers: hv: Select CONFIG_SYSFB only if EFI is enabledMichael Kelley1-1/+1
Commit 96959283a58d ("Drivers: hv: Always select CONFIG_SYSFB for Hyper-V guests") selects CONFIG_SYSFB for Hyper-V guests so that screen_info is available to the VMBus driver to get the location of the framebuffer in Generation 2 VMs. However, if CONFIG_HYPERV is enabled but CONFIG_EFI is not, a kernel link error results in ARM64 builds because screen_info is provided by the EFI firmware interface. While configuring an ARM64 Hyper-V guest without EFI isn't useful since EFI is required to boot, the configuration is still possible and the link error should be prevented. Fix this by making the selection of CONFIG_SYSFB conditional on CONFIG_EFI being defined. For Generation 1 VMs on x86/x64, which don't use EFI, the additional condition is OK because such VMs get the framebuffer information via a mechanism that doesn't use screen_info. Fixes: 96959283a58d ("Drivers: hv: Always select CONFIG_SYSFB for Hyper-V guests") Reported-by: Arnd Bergmann <arnd@arndb.de> Closes: https://lore.kernel.org/linux-hyperv/20250610091810.2638058-1-arnd@kernel.org/ Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202506080820.1wmkQufc-lkp@intel.com/ Signed-off-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/stable/20250613230059.380483-1-mhklinux%40outlook.com Reviewed-by: Roman Kisel <romank@linux.microsoft.com> Link: https://lore.kernel.org/r/20250613230059.380483-1-mhklinux@outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250613230059.380483-1-mhklinux@outlook.com>
2025-06-23sched/wait: Drop WQ_FLAG_EXCLUSIVE from add_wait_queue_priority()Sean Christopherson1-0/+8
Drop the setting of WQ_FLAG_EXCLUSIVE from add_wait_queue_priority() and instead have callers manually add the flag prior to adding their structure to the queue. Blindly setting WQ_FLAG_EXCLUSIVE is flawed, as the nature of exclusive, priority waiters means that only the first waiter added will ever receive notifications. Pushing the flawed behavior to callers will allow fixing the problem one hypervisor at a time (KVM added the flawed API, and then KVM's code was copy+pasted nearly verbatim by Xen and Hyper-V), and will also allow for adding an API that provides true exclusivity, i.e. that guarantees at most one priority waiter is in the queue. Opportunistically add a comment in Hyper-V to call out the mess. Xen privcmd's irqfd_wakefup() doesn't actually operate in exclusive mode, i.e. can be "fixed" simply by dropping WQ_FLAG_EXCLUSIVE. And KVM is primed to switch to the aforementioned fully exclusive API, i.e. won't be carrying the flawed code for long. No functional change intended. Tested-by: K Prateek Nayak <kprateek.nayak@amd.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20250522235223.3178519-7-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-06-03Merge tag 'hyperv-next-signed-20250602' of ↵Linus Torvalds4-61/+140
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv updates from Wei Liu: - Support for Virtual Trust Level (VTL) on arm64 (Roman Kisel) - Fixes for Hyper-V UIO driver (Long Li) - Fixes for Hyper-V PCI driver (Michael Kelley) - Select CONFIG_SYSFB for Hyper-V guests (Michael Kelley) - Documentation updates for Hyper-V VMBus (Michael Kelley) - Enhance logging for hv_kvp_daemon (Shradha Gupta) * tag 'hyperv-next-signed-20250602' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (23 commits) Drivers: hv: Always select CONFIG_SYSFB for Hyper-V guests Drivers: hv: vmbus: Add comments about races with "channels" sysfs dir Documentation: hyperv: Update VMBus doc with new features and info PCI: hv: Remove unnecessary flex array in struct pci_packet Drivers: hv: Remove hv_alloc/free_* helpers Drivers: hv: Use kzalloc for panic page allocation uio_hv_generic: Align ring size to system page uio_hv_generic: Use correct size for interrupt and monitor pages Drivers: hv: Allocate interrupt and monitor pages aligned to system page boundary arch/x86: Provide the CPU number in the wakeup AP callback x86/hyperv: Fix APIC ID and VP index confusion in hv_snp_boot_ap() PCI: hv: Get vPCI MSI IRQ domain from DeviceTree ACPI: irq: Introduce acpi_get_gsi_dispatcher() Drivers: hv: vmbus: Introduce hv_get_vmbus_root_device() Drivers: hv: vmbus: Get the IRQ number from DeviceTree dt-bindings: microsoft,vmbus: Add interrupt and DMA coherence properties arm64, x86: hyperv: Report the VTL the system boots in arm64: hyperv: Initialize the Virtual Trust Level field Drivers: hv: Provide arch-neutral implementation of get_vtl() Drivers: hv: Enable VTL mode for arm64 ...
2025-05-29Merge tag 'driver-core-6.16-rc1' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core Pull driver core updates from Greg KH: "Here are the driver core / kernfs changes for 6.16-rc1. Not a huge number of changes this development cycle, here's the summary of what is included in here: - kernfs locking tweaks, pushing some global locks down into a per-fs image lock - rust driver core and pci device bindings added for new features. - sysfs const work for bin_attributes. The final churn of switching away from and removing the transitional struct members, "read_new", "write_new" and "bin_attrs_new" will come after the merge window to avoid unnecesary merge conflicts. - auxbus device creation helpers added - fauxbus fix for creating sysfs files after the probe completed properly - other tiny updates for driver core things. All of these have been in linux-next for over a week with no reported issues" * tag 'driver-core-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: kernfs: Relax constraint in draining guard Documentation: embargoed-hardware-issues.rst: Remove myself drivers: hv: fix up const issue with vmbus_chan_bin_attrs firmware_loader: use SHA-256 library API instead of crypto_shash API docs: debugfs: do not recommend debugfs_remove_recursive PM: wakeup: Do not expose 4 device wakeup source APIs kernfs: switch global kernfs_rename_lock to per-fs lock kernfs: switch global kernfs_idr_lock to per-fs lock driver core: auxiliary bus: Fix IS_ERR() vs NULL mixup in __devm_auxiliary_device_create() sysfs: constify attribute_group::bin_attrs sysfs: constify bin_attribute argument of bin_attribute::read/write() software node: Correct a OOB check in software_node_get_reference_args() devres: simplify devm_kstrdup() using devm_kmemdup() platform: replace magic number with macro PLATFORM_DEVID_NONE component: do not try to unbind unbound components driver core: auxiliary bus: add device creation helpers driver core: faux: Add sysfs groups after probing
2025-05-23Drivers: hv: Always select CONFIG_SYSFB for Hyper-V guestsMichael Kelley1-0/+1
The Hyper-V host provides guest VMs with a range of MMIO addresses that guest VMBus drivers can use. The VMBus driver in Linux manages that MMIO space, and allocates portions to drivers upon request. As part of managing that MMIO space in a Generation 2 VM, the VMBus driver must reserve the portion of the MMIO space that Hyper-V has designated for the synthetic frame buffer, and not allocate this space to VMBus drivers other than graphics framebuffer drivers. The synthetic frame buffer MMIO area is described by the screen_info data structure that is passed to the Linux kernel at boot time, so the VMBus driver must access screen_info for Generation 2 VMs. (In Generation 1 VMs, the framebuffer MMIO space is communicated to the guest via a PCI pseudo-device, and access to screen_info is not needed.) In commit a07b50d80ab6 ("hyperv: avoid dependency on screen_info") the VMBus driver's access to screen_info is restricted to when CONFIG_SYSFB is enabled. CONFIG_SYSFB is typically enabled in kernels built for Hyper-V by virtue of having at least one of CONFIG_FB_EFI, CONFIG_FB_VESA, or CONFIG_SYSFB_SIMPLEFB enabled, so the restriction doesn't usually affect anything. But it's valid to have none of these enabled, in which case CONFIG_SYSFB is not enabled, and the VMBus driver is unable to properly reserve the framebuffer MMIO space for graphics framebuffer drivers. The framebuffer MMIO space may be assigned to some other VMBus driver, with undefined results. As an example, if a VM is using a PCI pass-thru NVMe controller to host the OS disk, the PCI NVMe controller is probed before any graphics devices, and the NVMe controller is assigned a portion of the framebuffer MMIO space. Hyper-V reports an error to Linux during the probe, and the OS disk fails to get setup. Then Linux fails to boot in the VM. Fix this by having CONFIG_HYPERV always select SYSFB. Then the VMBus driver in a Gen 2 VM can always reserve the MMIO space for the graphics framebuffer driver, and prevent the undefined behavior. But don't select SYSFB when building for HYPERV_VTL_MODE as VTLs other than VTL 0 don't have a framebuffer and aren't subject to the issue. Adding SYSFB in such cases is harmless, but would increase the image size for no purpose. Fixes: a07b50d80ab6 ("hyperv: avoid dependency on screen_info") Signed-off-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com> Link: https://lore.kernel.org/stable/20250520040143.6964-1-mhklinux%40outlook.com Link: https://lore.kernel.org/r/20250520040143.6964-1-mhklinux@outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250520040143.6964-1-mhklinux@outlook.com>
2025-05-23Drivers: hv: vmbus: Add comments about races with "channels" sysfs dirMichael Kelley1-2/+40
The VMBus driver code has some inherent races in the creation of the "channels" sysfs subdirectory and its per-channel numbered subdirectories. These races have not generally been recognized or understood. Add some comments to call them out. No code changes. Signed-off-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/20250514225508.52629-1-mhklinux@outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250514225508.52629-1-mhklinux@outlook.com>
2025-05-23Drivers: hv: Remove hv_alloc/free_* helpersLong Li1-39/+0
There are no users for those functions, remove them. Signed-off-by: Long Li <longli@microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1746492997-4599-6-git-send-email-longli@linuxonhyperv.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1746492997-4599-6-git-send-email-longli@linuxonhyperv.com>
2025-05-23Drivers: hv: Use kzalloc for panic page allocationLong Li1-3/+3
To prepare for removal of hv_alloc_* and hv_free* functions, use kzalloc/kfree directly for panic reporting page. Signed-off-by: Long Li <longli@microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1746492997-4599-5-git-send-email-longli@linuxonhyperv.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1746492997-4599-5-git-send-email-longli@linuxonhyperv.com>
2025-05-23Drivers: hv: Allocate interrupt and monitor pages aligned to system page ↵Long Li1-6/+17
boundary There are use cases that interrupt and monitor pages are mapped to user-mode through UIO, so they need to be system page aligned. Some Hyper-V allocation APIs introduced earlier broke those requirements. Fix this by using page allocation functions directly for interrupt and monitor pages. Cc: stable@vger.kernel.org Fixes: ca48739e59df ("Drivers: hv: vmbus: Move Hyper-V page allocator to arch neutral code") Signed-off-by: Long Li <longli@microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1746492997-4599-2-git-send-email-longli@linuxonhyperv.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1746492997-4599-2-git-send-email-longli@linuxonhyperv.com>
2025-05-23Drivers: hv: vmbus: Introduce hv_get_vmbus_root_device()Roman Kisel1-8/+15
The ARM64 PCI code for hyperv needs to know the VMBus root device, and it is private. Provide a function that returns it. Rename it from "hv_dev" as "hv_dev" as a symbol is very overloaded. No functional changes. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/20250428210742.435282-10-romank@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250428210742.435282-10-romank@linux.microsoft.com>
2025-05-23Drivers: hv: vmbus: Get the IRQ number from DeviceTreeRoman Kisel1-0/+30
The VMBus driver uses ACPI for interrupt assignment on arm64 hence it won't function in the VTL mode where only DeviceTree can be used. Update the VMBus driver to discover interrupt configuration from DT. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/20250428210742.435282-9-romank@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250428210742.435282-9-romank@linux.microsoft.com>
2025-05-23Drivers: hv: Provide arch-neutral implementation of get_vtl()Roman Kisel1-0/+31
To run in the VTL mode, Hyper-V drivers have to know what VTL the system boots in, and the arm64/hyperv code does not have the means to compute that. Refactor the code to hoist the function that detects VTL, make it arch-neutral to be able to employ it to get the VTL on arm64. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Link: https://lore.kernel.org/r/20250428210742.435282-5-romank@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250428210742.435282-5-romank@linux.microsoft.com>
2025-05-23Drivers: hv: Enable VTL mode for arm64Roman Kisel1-3/+3
Kconfig dependencies for arm64 guests on Hyper-V require that be ACPI enabled, and limit VTL mode to x86/x64. To enable VTL mode on arm64 as well, update the dependencies. Since VTL mode requires DeviceTree instead of ACPI, don’t require arm64 guests on Hyper-V to have ACPI unconditionally. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/20250428210742.435282-4-romank@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250428210742.435282-4-romank@linux.microsoft.com>
2025-05-21drivers: hv: fix up const issue with vmbus_chan_bin_attrsGreg Kroah-Hartman1-1/+1
In commit 9bec944506fa ("sysfs: constify attribute_group::bin_attrs"), the bin_attributes are now required to be const. Due to merge issues, the original commit could not modify this structure (it came in through a different branch.) Fix this up now by setting the variable properly. Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: Naman Jain <namjain@linux.microsoft.com> Fixes: 9bec944506fa ("sysfs: constify attribute_group::bin_attrs") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-15Merge tag 'net-6.15-rc7' of ↵Linus Torvalds1-62/+3
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Jakub Kicinski: "Including fixes from Bluetooth and wireless. A few more fixes for the locking changes trickling in. Nothing too alarming, I suspect those will continue for another release. Other than that things are slowing down nicely. Current release - fix to a fix: - Bluetooth: hci_event: use key encryption size when its known - tools: ynl-gen: allow multi-attr without nested-attributes again Current release - regressions: - locking fixes: - lock lower level devices when updating features - eth: bnxt_en: bring back rtnl_lock() in the bnxt_open() path - devmem: fix panic when Netlink socket closes after module unload Current release - new code bugs: - eth: txgbe: fixes for FW communication on new AML devices Previous releases - always broken: - sched: flush gso_skb list too during ->change(), avoid potential null-deref on reconfig - wifi: mt76: disable NAPI on driver removal - hv_netvsc: fix error 'nvsp_rndis_pkt_complete error status: 2'" * tag 'net-6.15-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (44 commits) net: devmem: fix kernel panic when netlink socket close after module unload tsnep: fix timestamping with a stacked DSA driver net/tls: fix kernel panic when alloc_page failed bnxt_en: bring back rtnl_lock() in the bnxt_open() path mlxsw: spectrum_router: Fix use-after-free when deleting GRE net devices wifi: mac80211: Set n_channels after allocating struct cfg80211_scan_request octeontx2-pf: Do not reallocate all ntuple filters wifi: mt76: mt7925: fix missing hdr_trans_tlv command for broadcast wtbl wifi: mt76: disable napi on driver removal Drivers: hv: vmbus: Remove vmbus_sendpacket_pagebuffer() hv_netvsc: Remove rmsg_pgcnt hv_netvsc: Preserve contiguous PFN grouping in the page buffer array hv_netvsc: Use vmbus_sendpacket_mpb_desc() to send VMBus messages Drivers: hv: Allow vmbus_sendpacket_mpb_desc() to create multiple ranges octeontx2-af: Fix CGX Receive counters net: ethernet: mtk_eth_soc: fix typo for declaration MT7988 ESW capability net: libwx: Fix FW mailbox unknown command net: libwx: Fix FW mailbox reply timeout net: txgbe: Fix to calculate EEPROM checksum for AML devices octeontx2-pf: macsec: Fix incorrect max transmit size in TX secy ...
2025-05-14Drivers: hv: vmbus: Remove vmbus_sendpacket_pagebuffer()Michael Kelley1-59/+0
With the netvsc driver changed to use vmbus_sendpacket_mpb_desc() instead of vmbus_sendpacket_pagebuffer(), the latter has no remaining callers. Remove it. Cc: <stable@vger.kernel.org> # 6.1.x Signed-off-by: Michael Kelley <mhklinux@outlook.com> Link: https://patch.msgid.link/20250513000604.1396-6-mhklinux@outlook.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-14Drivers: hv: Allow vmbus_sendpacket_mpb_desc() to create multiple rangesMichael Kelley1-3/+3
vmbus_sendpacket_mpb_desc() is currently used only by the storvsc driver and is hardcoded to create a single GPA range. To allow it to also be used by the netvsc driver to create multiple GPA ranges, no longer hardcode as having a single GPA range. Allow the calling driver to specify the rangecount in the supplied descriptor. Update the storvsc driver to reflect this new approach. Cc: <stable@vger.kernel.org> # 6.1.x Signed-off-by: Michael Kelley <mhklinux@outlook.com> Link: https://patch.msgid.link/20250513000604.1396-2-mhklinux@outlook.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-10Merge tag 'char-misc-6.15-rc6' of ↵Linus Torvalds2-1/+114
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc/IIO driver fixes from Greg KH: "Here are a bunch of small driver fixes (mostly all IIO) for 6.15-rc6. Included in here are: - loads of tiny IIO driver fixes for reported issues - hyperv driver fix for a much-reported and worked on sysfs ring buffer creation bug All of these have been in linux-next for over a week (the IIO ones for many weeks now), with no reported issues" * tag 'char-misc-6.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (30 commits) Drivers: hv: Make the sysfs node size for the ring buffer dynamic uio_hv_generic: Fix sysfs creation path for ring buffer iio: adis16201: Correct inclinometer channel resolution iio: adc: ad7606: fix serial register access iio: pressure: mprls0025pa: use aligned_s64 for timestamp iio: imu: adis16550: align buffers for timestamp staging: iio: adc: ad7816: Correct conditional logic for store mode iio: adc: ad7266: Fix potential timestamp alignment issue. iio: adc: ad7768-1: Fix insufficient alignment of timestamp. iio: adc: dln2: Use aligned_s64 for timestamp iio: accel: adxl355: Make timestamp 64-bit aligned using aligned_s64 iio: temp: maxim-thermocouple: Fix potential lack of DMA safe buffer. iio: chemical: pms7003: use aligned_s64 for timestamp iio: chemical: sps30: use aligned_s64 for timestamp iio: imu: inv_mpu6050: align buffer for timestamp iio: imu: st_lsm6dsx: Fix wakeup source leaks on device unbind iio: adc: qcom-spmi-iadc: Fix wakeup source leaks on device unbind iio: accel: fxls8962af: Fix wakeup source leaks on device unbind iio: adc: ad7380: fix event threshold shift iio: hid-sensor-prox: Fix incorrect OFFSET calculation ...
2025-05-02Drivers: hv: Make the sysfs node size for the ring buffer dynamicNaman Jain1-1/+10
The ring buffer size varies across VMBus channels. The size of sysfs node for the ring buffer is currently hardcoded to 4 MB. Userspace clients either use fstat() or hardcode this size for doing mmap(). To address this, make the sysfs node size dynamic to reflect the actual ring buffer size for each channel. This will ensure that fstat() on ring sysfs node always returns the correct size of ring buffer. Reviewed-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Naman Jain <namjain@linux.microsoft.com> Link: https://lore.kernel.org/r/20250502074811.2022-3-namjain@linux.microsoft.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-02uio_hv_generic: Fix sysfs creation path for ring bufferNaman Jain2-1/+105
On regular bootup, devices get registered to VMBus first, so when uio_hv_generic driver for a particular device type is probed, the device is already initialized and added, so sysfs creation in hv_uio_probe() works fine. However, when the device is removed and brought back, the channel gets rescinded and the device again gets registered to VMBus. However this time, the uio_hv_generic driver is already registered to probe for that device and in this case sysfs creation is tried before the device's kobject gets initialized completely. Fix this by moving the core logic of sysfs creation of ring buffer, from uio_hv_generic to HyperV's VMBus driver, where the rest of the sysfs attributes for the channels are defined. While doing that, make use of attribute groups and macros, instead of creating sysfs directly, to ensure better error handling and code flow. Problematic path: vmbus_process_offer (A new offer comes for the VMBus device) vmbus_add_channel_work vmbus_device_register |-> device_register | |... | |-> hv_uio_probe | |... | |-> sysfs_create_bin_file (leads to a warning as | the primary channel's kobject, which is used to | create the sysfs file, is not yet initialized) |-> kset_create_and_add |-> vmbus_add_channel_kobj (initialization of the primary channel's kobject happens later) Above code flow is sequential and the warning is always reproducible in this path. Fixes: 9ab877a6ccf8 ("uio_hv_generic: make ring buffer attribute for primary channel") Cc: stable@kernel.org Suggested-by: Saurabh Sengar <ssengar@linux.microsoft.com> Suggested-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Naman Jain <namjain@linux.microsoft.com> Link: https://lore.kernel.org/r/20250502074811.2022-2-namjain@linux.microsoft.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-25Drivers: hv: Fix bad ref to hv_synic_eventring_tail when CPU goes offlineMichael Kelley1-3/+5
When a CPU goes offline, hv_common_cpu_die() frees the hv_synic_eventring_tail memory for the CPU. But in a normal VM (i.e., not running in the root partition) the per-CPU memory has not been allocated, resulting in a bad memory reference and oops when computing the argument to kfree(). Fix this by freeing the memory only when running in the root partition. Fixes: 04df7ac39943 ("Drivers: hv: Introduce per-cpu event ring tail") Signed-off-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Link: https://lore.kernel.org/r/20250421163134.2024-1-mhklinux@outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250421163134.2024-1-mhklinux@outlook.com>
2025-04-07Drivers: hv: Fix bad pointer dereference in hv_get_partition_idNuno Das Neves1-1/+1
'output' is already a pointer to the output argument, it should be passed directly to hv_do_hypercall() without the '&' operator. Fixes: e96204e5e96e ("hyperv: Move hv_current_partition_id to arch-generic code") Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1743528737-20310-1-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1743528737-20310-1-git-send-email-nunodasneves@linux.microsoft.com>
2025-04-01Merge tag 'mm-stable-2025-03-30-16-52' of ↵Linus Torvalds1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - The series "Enable strict percpu address space checks" from Uros Bizjak uses x86 named address space qualifiers to provide compile-time checking of percpu area accesses. This has caused a small amount of fallout - two or three issues were reported. In all cases the calling code was found to be incorrect. - The series "Some cleanup for memcg" from Chen Ridong implements some relatively monir cleanups for the memcontrol code. - The series "mm: fixes for device-exclusive entries (hmm)" from David Hildenbrand fixes a boatload of issues which David found then using device-exclusive PTE entries when THP is enabled. More work is needed, but this makes thins better - our own HMM selftests now succeed. - The series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed remove the z3fold and zbud implementations. They have been deprecated for half a year and nobody has complained. - The series "mm: further simplify VMA merge operation" from Lorenzo Stoakes implements numerous simplifications in this area. No runtime effects are anticipated. - The series "mm/madvise: remove redundant mmap_lock operations from process_madvise()" from SeongJae Park rationalizes the locking in the madvise() implementation. Performance gains of 20-25% were observed in one MADV_DONTNEED microbenchmark. - The series "Tiny cleanup and improvements about SWAP code" from Baoquan He contains a number of touchups to issues which Baoquan noticed when working on the swap code. - The series "mm: kmemleak: Usability improvements" from Catalin Marinas implements a couple of improvements to the kmemleak user-visible output. - The series "mm/damon/paddr: fix large folios access and schemes handling" from Usama Arif provides a couple of fixes for DAMON's handling of large folios. - The series "mm/damon/core: fix wrong and/or useless damos_walk() behaviors" from SeongJae Park fixes a few issues with the accuracy of kdamond's walking of DAMON regions. - The series "expose mapping wrprotect, fix fb_defio use" from Lorenzo Stoakes changes the interaction between framebuffer deferred-io and core MM. No functional changes are anticipated - this is preparatory work for the future removal of page structure fields. - The series "mm/damon: add support for hugepage_size DAMOS filter" from Usama Arif adds a DAMOS filter which permits the filtering by huge page sizes. - The series "mm: permit guard regions for file-backed/shmem mappings" from Lorenzo Stoakes extends the guard region feature from its present "anon mappings only" state. The feature now covers shmem and file-backed mappings. - The series "mm: batched unmap lazyfree large folios during reclamation" from Barry Song cleans up and speeds up the unmapping for pte-mapped large folios. - The series "reimplement per-vma lock as a refcount" from Suren Baghdasaryan puts the vm_lock back into the vma. Our reasons for pulling it out were largely bogus and that change made the code more messy. This patchset provides small (0-10%) improvements on one microbenchmark. - The series "Docs/mm/damon: misc DAMOS filters documentation fixes and improves" from SeongJae Park does some maintenance work on the DAMON docs. - The series "hugetlb/CMA improvements for large systems" from Frank van der Linden addresses a pile of issues which have been observed when using CMA on large machines. - The series "mm/damon: introduce DAMOS filter type for unmapped pages" from SeongJae Park enables users of DMAON/DAMOS to filter my the page's mapped/unmapped status. - The series "zsmalloc/zram: there be preemption" from Sergey Senozhatsky teaches zram to run its compression and decompression operations preemptibly. - The series "selftests/mm: Some cleanups from trying to run them" from Brendan Jackman fixes a pile of unrelated issues which Brendan encountered while runnimg our selftests. - The series "fs/proc/task_mmu: add guard region bit to pagemap" from Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to determine whether a particular page is a guard page. - The series "mm, swap: remove swap slot cache" from Kairui Song removes the swap slot cache from the allocation path - it simply wasn't being effective. - The series "mm: cleanups for device-exclusive entries (hmm)" from David Hildenbrand implements a number of unrelated cleanups in this code. - The series "mm: Rework generic PTDUMP configs" from Anshuman Khandual implements a number of preparatoty cleanups to the GENERIC_PTDUMP Kconfig logic. - The series "mm/damon: auto-tune aggregation interval" from SeongJae Park implements a feedback-driven automatic tuning feature for DAMON's aggregation interval tuning. - The series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in powerpc, sparc and x86 lazy MMU implementations. Ryan did this in preparation for implementing lazy mmu mode for arm64 to optimize vmalloc. - The series "mm/page_alloc: Some clarifications for migratetype fallback" from Brendan Jackman reworks some commentary to make the code easier to follow. - The series "page_counter cleanup and size reduction" from Shakeel Butt cleans up the page_counter code and fixes a size increase which we accidentally added late last year. - The series "Add a command line option that enables control of how many threads should be used to allocate huge pages" from Thomas Prescher does that. It allows the careful operator to significantly reduce boot time by tuning the parallalization of huge page initialization. - The series "Fix calculations in trace_balance_dirty_pages() for cgwb" from Tang Yizhou fixes the tracing output from the dirty page balancing code. - The series "mm/damon: make allow filters after reject filters useful and intuitive" from SeongJae Park improves the handling of allow and reject filters. Behaviour is made more consistent and the documention is updated accordingly. - The series "Switch zswap to object read/write APIs" from Yosry Ahmed updates zswap to the new object read/write APIs and thus permits the removal of some legacy code from zpool and zsmalloc. - The series "Some trivial cleanups for shmem" from Baolin Wang does as it claims. - The series "fs/dax: Fix ZONE_DEVICE page reference counts" from Alistair Popple regularizes the weird ZONE_DEVICE page refcount handling in DAX, permittig the removal of a number of special-case checks. - The series "refactor mremap and fix bug" from Lorenzo Stoakes is a preparatoty refactoring and cleanup of the mremap() code. - The series "mm: MM owner tracking for large folios (!hugetlb) + CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in which we determine whether a large folio is known to be mapped exclusively into a single MM. - The series "mm/damon: add sysfs dirs for managing DAMOS filters based on handling layers" from SeongJae Park adds a couple of new sysfs directories to ease the management of DAMON/DAMOS filters. - The series "arch, mm: reduce code duplication in mem_init()" from Mike Rapoport consolidates many per-arch implementations of mem_init() into code generic code, where that is practical. - The series "mm/damon/sysfs: commit parameters online via damon_call()" from SeongJae Park continues the cleaning up of sysfs access to DAMON internal data. - The series "mm: page_ext: Introduce new iteration API" from Luiz Capitulino reworks the page_ext initialization to fix a boot-time crash which was observed with an unusual combination of compile and cmdline options. - The series "Buddy allocator like (or non-uniform) folio split" from Zi Yan reworks the code to split a folio into smaller folios. The main benefit is lessened memory consumption: fewer post-split folios are generated. - The series "Minimize xa_node allocation during xarry split" from Zi Yan reduces the number of xarray xa_nodes which are generated during an xarray split. - The series "drivers/base/memory: Two cleanups" from Gavin Shan performs some maintenance work on the drivers/base/memory code. - The series "Add tracepoints for lowmem reserves, watermarks and totalreserve_pages" from Martin Liu adds some more tracepoints to the page allocator code. - The series "mm/madvise: cleanup requests validations and classifications" from SeongJae Park cleans up some warts which SeongJae observed during his earlier madvise work. - The series "mm/hwpoison: Fix regressions in memory failure handling" from Shuai Xue addresses two quite serious regressions which Shuai has observed in the memory-failure implementation. - The series "mm: reliable huge page allocator" from Johannes Weiner makes huge page allocations cheaper and more reliable by reducing fragmentation. - The series "Minor memcg cleanups & prep for memdescs" from Matthew Wilcox is preparatory work for the future implementation of memdescs. - The series "track memory used by balloon drivers" from Nico Pache introduces a way to track memory used by our various balloon drivers. - The series "mm/damon: introduce DAMOS filter type for active pages" from Nhat Pham permits users to filter for active/inactive pages, separately for file and anon pages. - The series "Adding Proactive Memory Reclaim Statistics" from Hao Jia separates the proactive reclaim statistics from the direct reclaim statistics. - The series "mm/vmscan: don't try to reclaim hwpoison folio" from Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim code. * tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits) mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex() x86/mm: restore early initialization of high_memory for 32-bits mm/vmscan: don't try to reclaim hwpoison folio mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper cgroup: docs: add pswpin and pswpout items in cgroup v2 doc mm: vmscan: split proactive reclaim statistics from direct reclaim statistics selftests/mm: speed up split_huge_page_test selftests/mm: uffd-unit-tests support for hugepages > 2M docs/mm/damon/design: document active DAMOS filter type mm/damon: implement a new DAMOS filter type for active pages fs/dax: don't disassociate zero page entries MM documentation: add "Unaccepted" meminfo entry selftests/mm: add commentary about 9pfs bugs fork: use __vmalloc_node() for stack allocation docs/mm: Physical Memory: Populate the "Zones" section xen: balloon: update the NR_BALLOON_PAGES state hv_balloon: update the NR_BALLOON_PAGES state balloon_compaction: update the NR_BALLOON_PAGES state meminfo: add a per node counter for balloon drivers mm: remove references to folio in __memcg_kmem_uncharge_page() ...
2025-03-25Merge tag 'hyperv-next-signed-20250324' of ↵Linus Torvalds16-69/+5927
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv updates from Wei Liu: - Add support for running as the root partition in Hyper-V (Microsoft Hypervisor) by exposing /dev/mshv (Nuno and various people) - Add support for CPU offlining in Hyper-V (Hamza Mahfooz) - Misc fixes and cleanups (Roman Kisel, Tianyu Lan, Wei Liu, Michael Kelley, Thorsten Blum) * tag 'hyperv-next-signed-20250324' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (24 commits) x86/hyperv: fix an indentation issue in mshyperv.h x86/hyperv: Add comments about hv_vpset and var size hypercall input args Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs hyperv: Add definitions for root partition driver to hv headers x86: hyperv: Add mshv_handler() irq handler and setup function Drivers: hv: Introduce per-cpu event ring tail Drivers: hv: Export some functions for use by root partition module acpi: numa: Export node_to_pxm() hyperv: Introduce hv_recommend_using_aeoi() arm64/hyperv: Add some missing functions to arm64 x86/mshyperv: Add support for extended Hyper-V features hyperv: Log hypercall status codes as strings x86/hyperv: Fix check of return value from snp_set_vmsa() x86/hyperv: Add VTL mode callback for restarting the system x86/hyperv: Add VTL mode emergency restart callback hyperv: Remove unused union and structs hyperv: Add CONFIG_MSHV_ROOT to gate root partition support hyperv: Change hv_root_partition into a function hyperv: Convert hypercall statuses to linux error codes drivers/hv: add CPU offlining support ...
2025-03-21hv_balloon: update the NR_BALLOON_PAGES stateNico Pache1-0/+2
Update the NR_BALLOON_PAGES counter when pages are added to or removed from the Hyper-V balloon. Link: https://lkml.kernel.org/r/20250314213757.244258-4-npache@redhat.com Signed-off-by: Nico Pache <npache@redhat.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Cc: Alexander Atanasov <alexander.atanasov@virtuozzo.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: David Hildenbrand <david@redhat.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Juegren Gross <jgross@suse.com> Cc: Kanchana P Sridhar <kanchana.p.sridhar@intel.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Wei Liu <wei.liu@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-21Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMsNuno Das Neves12-1/+5439
Provide a set of IOCTLs for creating and managing child partitions when running as root partition on Hyper-V. The new driver is enabled via CONFIG_MSHV_ROOT. A brief overview of the interface: MSHV_CREATE_PARTITION is the entry point, returning a file descriptor representing a child partition. IOCTLs on this fd can be used to map memory, create VPs, etc. Creating a VP returns another file descriptor representing that VP which in turn has another set of corresponding IOCTLs for running the VP, getting/setting state, etc. MSHV_ROOT_HVCALL is a generic "passthrough" hypercall IOCTL which can be used for a number of partition or VP hypercalls. This is for hypercalls that do not affect any state in the kernel driver, such as getting and setting VP registers and partition properties, translating addresses, etc. It is "passthrough" because the binary input and output for the hypercall is only interpreted by the VMM - the kernel driver does nothing but insert the VP and partition id where necessary (which are always in the same place), and execute the hypercall. Co-developed-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com> Signed-off-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com> Co-developed-by: Jinank Jain <jinankjain@microsoft.com> Signed-off-by: Jinank Jain <jinankjain@microsoft.com> Co-developed-by: Mukesh Rathor <mrathor@linux.microsoft.com> Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com> Co-developed-by: Muminul Islam <muislam@microsoft.com> Signed-off-by: Muminul Islam <muislam@microsoft.com> Co-developed-by: Praveen K Paladugu <prapal@linux.microsoft.com> Signed-off-by: Praveen K Paladugu <prapal@linux.microsoft.com> Co-developed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Co-developed-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Roman Kisel <romank@linux.microsoft.com> Link: https://lore.kernel.org/r/1741980536-3865-11-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1741980536-3865-11-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-20x86: hyperv: Add mshv_handler() irq handler and setup functionNuno Das Neves1-0/+5
Add mshv_handler() to process messages related to managing guest partitions such as intercepts, doorbells, and scheduling messages. In a (non-nested) root partition, the same interrupt vector is shared between the vmbus and mshv_root drivers. Introduce a stub for mshv_handler() and call it in sysvec_hyperv_callback alongside vmbus_handler(). Even though both handlers will be called for every Hyper-V interrupt, the messages for each driver are delivered to different offsets within the SYNIC message page, so they won't step on each other. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Link: https://lore.kernel.org/r/1741980536-3865-9-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1741980536-3865-9-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-20Drivers: hv: Introduce per-cpu event ring tailNuno Das Neves1-4/+37
Add a pointer hv_synic_eventring_tail to track the tail pointer for the SynIC event ring buffer for each SINT. This will be used by the mshv driver, but must be tracked independently since the driver module could be removed and re-inserted. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Link: https://lore.kernel.org/r/1741980536-3865-8-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1741980536-3865-8-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-20Drivers: hv: Export some functions for use by root partition moduleNuno Das Neves1-1/+2
hv_get_hypervisor_version(), hv_call_deposit_pages(), and hv_call_create_vp(), are all needed in-module with CONFIG_MSHV_ROOT=m. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@microsoft.linux.com> Reviewed-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Link: https://lore.kernel.org/r/1741980536-3865-7-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1741980536-3865-7-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-20hyperv: Introduce hv_recommend_using_aeoi()Nuno Das Neves1-11/+1
Factor out the check for enabling auto eoi, to be reused in root partition code. No functional changes. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Link: https://lore.kernel.org/r/1741980536-3865-5-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1741980536-3865-5-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-20hyperv: Log hypercall status codes as stringsNuno Das Neves2-39/+100
Introduce hv_status_printk() macros as a convenience to log hypercall errors, formatting them with the status code (HV_STATUS_*) as a raw hex value and also as a string, which saves some time while debugging. Create a table of HV_STATUS_ codes with strings and mapped errnos, and use it for hv_result_to_string() and hv_result_to_errno(). Use the new hv_status_printk()s in hv_proc.c, hyperv-iommu.c, and irqdomain.c hypercalls to aid debugging in the root partition. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Link: https://lore.kernel.org/r/1741980536-3865-2-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1741980536-3865-2-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-20hyperv: Add CONFIG_MSHV_ROOT to gate root partition supportNuno Das Neves3-2/+22
CONFIG_MSHV_ROOT allows kernels built to run as a normal Hyper-V guest to exclude the root partition code, which is expected to grow significantly over time. This option is a tristate so future driver code can be built as a (m)odule, allowing faster development iteration cycles. If CONFIG_MSHV_ROOT is disabled, don't compile hv_proc.c, and stub hv_root_partition() to return false unconditionally. This allows the compiler to optimize away root partition code blocks since they will be disabled at compile time. In the case of booting as root partition *without* CONFIG_MSHV_ROOT enabled, print a critical error (the kernel will likely crash). Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1740167795-13296-4-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1740167795-13296-4-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-10Drivers: hv: vmbus: Don't release fb_mmio resource in vmbus_free_mmio()Michael Kelley1-0/+13
The VMBus driver manages the MMIO space it owns via the hyperv_mmio resource tree. Because the synthetic video framebuffer portion of the MMIO space is initially setup by the Hyper-V host for each guest, the VMBus driver does an early reserve of that portion of MMIO space in the hyperv_mmio resource tree. It saves a pointer to that resource in fb_mmio. When a VMBus driver requests MMIO space and passes "true" for the "fb_overlap_ok" argument, the reserved framebuffer space is used if possible. In that case it's not necessary to do another request against the "shadow" hyperv_mmio resource tree because that resource was already requested in the early reserve steps. However, the vmbus_free_mmio() function currently does no special handling for the fb_mmio resource. When a framebuffer device is removed, or the driver is unbound, the current code for vmbus_free_mmio() releases the reserved resource, leaving fb_mmio pointing to memory that has been freed. If the same or another driver is subsequently bound to the device, vmbus_allocate_mmio() checks against fb_mmio, and potentially gets garbage. Furthermore a second unbind operation produces this "nonexistent resource" error because of the unbalanced behavior between vmbus_allocate_mmio() and vmbus_free_mmio(): [ 55.499643] resource: Trying to free nonexistent resource <0x00000000f0000000-0x00000000f07fffff> Fix this by adding logic to vmbus_free_mmio() to recognize when MMIO space in the fb_mmio reserved area would be released, and don't release it. This filtering ensures the fb_mmio resource always exists, and makes vmbus_free_mmio() more parallel with vmbus_allocate_mmio(). Fixes: be000f93e5d7 ("drivers:hv: Track allocations of children of hv_vmbus in private resource tree") Signed-off-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Saurabh Sengar <ssengar@linux.microsoft.com> Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com> Link: https://lore.kernel.org/r/20250310035208.275764-1-mhklinux@outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250310035208.275764-1-mhklinux@outlook.com>
2025-02-22hyperv: Change hv_root_partition into a functionNuno Das Neves3-12/+32
Introduce hv_curr_partition_type to store the partition type as an enum. Right now this is limited to guest or root partition, but there will be other kinds in future and the enum is easily extensible. Set up hv_curr_partition_type early in Hyper-V initialization with hv_identify_partition_type(). hv_root_partition() just queries this value, and shouldn't be called before that. Making this check into a function sets the stage for adding a config option to gate the compilation of root partition code. In particular, hv_root_partition() can be stubbed out always be false if root partition support isn't desired. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1740167795-13296-3-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1740167795-13296-3-git-send-email-nunodasneves@linux.microsoft.com>
2025-02-22hyperv: Convert hypercall statuses to linux error codesNuno Das Neves2-5/+39
Return linux-friendly error codes from hypercall helper functions, which allows them to be used more flexibly. Introduce hv_result_to_errno() for this purpose, which also handles the special value U64_MAX returned from hv_do_hypercall(). Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1740167795-13296-2-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1740167795-13296-2-git-send-email-nunodasneves@linux.microsoft.com>
2025-02-13drivers/hv: add CPU offlining supportHamza Mahfooz1-21/+51
Currently, it is tedious to offline CPUs in a Hyper-V VM since CPUs may have VMBus channels attached to them that a user would have to manually rebind elsewhere. So, as made mention of in commit d570aec0f2154 ("Drivers: hv: vmbus: Synchronize init_vp_index() vs. CPU hotplug"), rebind channels associated with CPUs that a user is trying to offline to a new "randomly" selected CPU. Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Michael Kelley <mhklinux@outlook.com> Cc: Wei Liu <wei.liu@kernel.org> Signed-off-by: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/20250117203309.192072-3-hamzamahfooz@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250117203309.192072-3-hamzamahfooz@linux.microsoft.com>
2025-02-13drivers/hv: introduce vmbus_channel_set_cpu()Hamza Mahfooz1-21/+31
The core functionality in target_cpu_store() is also needed in a subsequent patch for automatically changing the CPU when taking a CPU offline. As such, factor out the body of target_cpu_store() into new function vmbus_channel_set_cpu() that can also be used elsewhere. No functional change is intended. Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Michael Kelley <mhklinux@outlook.com> Cc: Wei Liu <wei.liu@kernel.org> Signed-off-by: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/20250117203309.192072-2-hamzamahfooz@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250117203309.192072-2-hamzamahfooz@linux.microsoft.com>
2025-02-13hyperv: Move arch/x86/hyperv/hv_proc.c to drivers/hvNuno Das Neves2-1/+195
These helpers are not specific to x86_64 and will be needed by common code. Remove some unnecessary #includes. Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Link: https://lore.kernel.org/r/1738955002-20821-3-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1738955002-20821-3-git-send-email-nunodasneves@linux.microsoft.com>
2025-02-13hyperv: Move hv_current_partition_id to arch-generic codeNuno Das Neves1-0/+22
Move hv_current_partition_id and hv_get_partition_id() to hv_common.c, and call hv_get_partition_id() on arm64 in hyperv_init(). These aren't specific to x86_64 and will be needed by common code. Set hv_current_partition_id to HV_PARTITION_ID_SELF by default. Rename struct hv_get_partition_id to hv_output_get_partition_id, to make it distinct from the function hv_get_partition_id(), and match the original Hyper-V struct name. Remove the BUG()s. Failing to get the id need not crash the machine. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1738955002-20821-2-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1738955002-20821-2-git-send-email-nunodasneves@linux.microsoft.com>
2025-01-28treewide: const qualify ctl_tables where applicableJoel Granados1-1/+1
Add the const qualifier to all the ctl_tables in the tree except for watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls, loadpin_sysctl_table and the ones calling register_net_sysctl (./net, drivers/inifiniband dirs). These are special cases as they use a registration function with a non-const qualified ctl_table argument or modify the arrays before passing them on to the registration function. Constifying ctl_table structs will prevent the modification of proc_handler function pointers as the arrays would reside in .rodata. This is made possible after commit 78eb4ea25cd5 ("sysctl: treewide: constify the ctl_table argument of proc_handlers") constified all the proc_handlers. Created this by running an spatch followed by a sed command: Spatch: virtual patch @ depends on !(file in "net") disable optional_qualifier @ identifier table_name != { watchdog_hardlockup_sysctl, iwcm_ctl_table, ucma_ctl_table, memory_allocation_profiling_sysctls, loadpin_sysctl_table }; @@ + const struct ctl_table table_name [] = { ... }; sed: sed --in-place \ -e "s/struct ctl_table .table = &uts_kern/const struct ctl_table *table = \&uts_kern/" \ kernel/utsname_sysctl.c Reviewed-by: Song Liu <song@kernel.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> # for kernel/trace/ Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> # SCSI Reviewed-by: Darrick J. Wong <djwong@kernel.org> # xfs Acked-by: Jani Nikula <jani.nikula@intel.com> Acked-by: Corey Minyard <cminyard@mvista.com> Acked-by: Wei Liu <wei.liu@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Bill O'Donnell <bodonnel@redhat.com> Acked-by: Baoquan He <bhe@redhat.com> Acked-by: Ashutosh Dixit <ashutosh.dixit@intel.com> Acked-by: Anna Schumaker <anna.schumaker@oracle.com> Signed-off-by: Joel Granados <joel.granados@kernel.org>
2025-01-10hyperv: Enable the hypercall output page for the VTL modeRoman Kisel1-3/+8
Due to the hypercall page not being allocated in the VTL mode, the code resorts to using a part of the input page. Allocate the hypercall output page in the VTL mode thus enabling it to use it for output and share code with dom0. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Link: https://lore.kernel.org/r/20250108222138.1623703-4-romank@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250108222138.1623703-4-romank@linux.microsoft.com>
2025-01-10hv_balloon: Fallback to generic_online_page() for non-HV hot added memJacob Pan1-8/+10
The Hyper-V balloon driver installs a custom callback for handling page onlining operations performed by the memory hotplug subsystem. This custom callback is global, and overrides the default callback (generic_online_page) that Linux otherwise uses. The custom callback properly handles memory that is hot-added by the balloon driver as part of a Hyper-V hot-add region. But memory can also be hot-added directly by a device driver for a vPCI device, particularly GPUs. In such a case, the custom callback installed by the balloon driver runs, but won't find the page in its hot-add region list and doesn't online it, which could cause driver initialization failures. Fix this by having the balloon custom callback run generic_online_page() when the page isn't part of a Hyper-V hot-add region, thereby doing the default Linux behavior. This allows device driver hot-adds to work properly. Similar cases are handled the same way in the virtio-mem driver. Suggested-by: Vikram Sethi <vsethi@nvidia.com> Tested-by: Michael Frohlich <mfrohlich@microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Jacob Pan <jacob.pan@linux.microsoft.com> Link: https://lore.kernel.org/r/20250107180918.1053933-1-jacob.pan@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250107180918.1053933-1-jacob.pan@linux.microsoft.com>
2025-01-10Drivers: hv: vmbus: Log on missing offers if anyJohn Starks1-0/+17
When resuming from hibernation, log any channels that were present before hibernation but now are gone. In general, the boot-time devices configured for a resuming VM should be the same as the devices in the VM at the time of hibernation. It's uncommon for the configuration to have been changed such that offers are missing. Changing the configuration violates the rules for hibernation anyway. The cleanup of missing channels is not straight-forward and dependent on individual device driver functionality and implementation, so it can be added in future with separate changes. Signed-off-by: John Starks <jostarks@microsoft.com> Co-developed-by: Naman Jain <namjain@linux.microsoft.com> Signed-off-by: Naman Jain <namjain@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/20250102130712.1661-3-namjain@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250102130712.1661-3-namjain@linux.microsoft.com>
2025-01-10Drivers: hv: vmbus: Wait for boot-time offers during boot and resumeNaman Jain4-44/+51
Channel offers are requested during VMBus initialization and resume from hibernation. Add support to wait for all boot-time channel offers to be delivered and processed before returning from vmbus_request_offers. This is in analogy to a PCI bus not returning from probe until it has scanned all devices on the bus. Without this, user mode can race with VMBus initialization and miss channel offers. User mode has no way to work around this other than sleeping for a while, since there is no way to know when VMBus has finished processing boot-time offers. With this added functionality, remove earlier logic which keeps track of count of offered channels post resume from hibernation. Once all offers delivered message is received, no further boot-time offers are going to be received. Consequently, logic to prevent suspend from happening after previous resume had missing offers, is also removed. Co-developed-by: John Starks <jostarks@microsoft.com> Signed-off-by: John Starks <jostarks@microsoft.com> Signed-off-by: Naman Jain <namjain@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/20250102130712.1661-2-namjain@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250102130712.1661-2-namjain@linux.microsoft.com>
2025-01-10Drivers: hv: Don't assume cpu_possible_mask is denseMichael Kelley1-2/+2
Current code allocates the hv_vp_index array with size num_possible_cpus(). This code assumes cpu_possible_mask is dense, which is not true in the general case per [1]. If cpu_possible_mask is sparse, the array might be indexed by a value beyond the size of the array. However, the configurations that Hyper-V provides to guest VMs on x86 and ARM64 hardware, in combination with how architecture specific code assigns Linux CPU numbers, *does* always produce a dense cpu_possible_mask. So the dense assumption is not currently causing failures. But for robustness against future changes in how cpu_possible_mask is populated, update the code to no longer assume dense. The correct approach is to allocate and initialize the array using size "nr_cpu_ids". While this leaves unused array entries corresponding to holes in cpu_possible_mask, the holes are assumed to be minimal and hence the amount of memory wasted by unused entries is minimal. Using nr_cpu_ids also reduces initialization time, in that the loop to initialize the array currently rescans cpu_possible_mask on each iteration. This is n-squared in the number of CPUs, which could be significant for large CPU counts. [1] https://lore.kernel.org/lkml/SN6PR02MB4157210CC36B2593F8572E5ED4692@SN6PR02MB4157.namprd02.prod.outlook.com/ Signed-off-by: Michael Kelley <mhklinux@outlook.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20241003035333.49261-3-mhklinux@outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20241003035333.49261-3-mhklinux@outlook.com>
2025-01-10hyperv: Switch from hyperv-tlfs.h to hyperv/hvhdk.hNuno Das Neves5-6/+6
Switch to using hvhdk.h everywhere in the kernel. This header includes all the new Hyper-V headers in include/hyperv, which form a superset of the definitions found in hyperv-tlfs.h. This makes it easier to add new Hyper-V interfaces without being restricted to those in the TLFS doc (reflected in hyperv-tlfs.h). To be more consistent with the original Hyper-V code, the names of some definitions are changed slightly. Update those where needed. Update comments in mshyperv.h files to point to include/hyperv for adding new definitions. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Link: https://lore.kernel.org/r/1732577084-2122-5-git-send-email-nunodasneves@linux.microsoft.com Link: https://lore.kernel.org/r/20250108222138.1623703-3-romank@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2024-12-09Drivers: hv: util: Avoid accessing a ringbuffer not initialized yetMichael Kelley4-0/+23
If the KVP (or VSS) daemon starts before the VMBus channel's ringbuffer is fully initialized, we can hit the panic below: hv_utils: Registering HyperV Utility Driver hv_vmbus: registering driver hv_utils ... BUG: kernel NULL pointer dereference, address: 0000000000000000 CPU: 44 UID: 0 PID: 2552 Comm: hv_kvp_daemon Tainted: G E 6.11.0-rc3+ #1 RIP: 0010:hv_pkt_iter_first+0x12/0xd0 Call Trace: ... vmbus_recvpacket hv_kvp_onchannelcallback vmbus_on_event tasklet_action_common tasklet_action handle_softirqs irq_exit_rcu sysvec_hyperv_stimer0 </IRQ> <TASK> asm_sysvec_hyperv_stimer0 ... kvp_register_done hvt_op_read vfs_read ksys_read __x64_sys_read This can happen because the KVP/VSS channel callback can be invoked even before the channel is fully opened: 1) as soon as hv_kvp_init() -> hvutil_transport_init() creates /dev/vmbus/hv_kvp, the kvp daemon can open the device file immediately and register itself to the driver by writing a message KVP_OP_REGISTER1 to the file (which is handled by kvp_on_msg() ->kvp_handle_handshake()) and reading the file for the driver's response, which is handled by hvt_op_read(), which calls hvt->on_read(), i.e. kvp_register_done(). 2) the problem with kvp_register_done() is that it can cause the channel callback to be called even before the channel is fully opened, and when the channel callback is starting to run, util_probe()-> vmbus_open() may have not initialized the ringbuffer yet, so the callback can hit the panic of NULL pointer dereference. To reproduce the panic consistently, we can add a "ssleep(10)" for KVP in __vmbus_open(), just before the first hv_ringbuffer_init(), and then we unload and reload the driver hv_utils, and run the daemon manually within the 10 seconds. Fix the panic by reordering the steps in util_probe() so the char dev entry used by the KVP or VSS daemon is not created until after vmbus_open() has completed. This reordering prevents the race condition from happening. Reported-by: Dexuan Cui <decui@microsoft.com> Fixes: e0fa3e5e7df6 ("Drivers: hv: utils: fix a race on userspace daemons registration") Cc: stable@vger.kernel.org Signed-off-by: Michael Kelley <mhklinux@outlook.com> Acked-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20241106154247.2271-3-mhklinux@outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20241106154247.2271-3-mhklinux@outlook.com>
2024-12-09Drivers: hv: util: Don't force error code to ENODEV in util_probe()Michael Kelley1-3/+1
If the util_init function call in util_probe() returns an error code, util_probe() always return ENODEV, and the error code from the util_init function is lost. The error message output in the caller, vmbus_probe(), doesn't show the real error code. Fix this by just returning the error code from the util_init function. There doesn't seem to be a reason to force ENODEV, as other errors such as ENOMEM can already be returned from util_probe(). And the code in call_driver_probe() implies that ENODEV should mean that a matching driver wasn't found, which is not the case here. Suggested-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Michael Kelley <mhklinux@outlook.com> Acked-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20241106154247.2271-2-mhklinux@outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20241106154247.2271-2-mhklinux@outlook.com>
2024-12-09drivers: hv: Convert open-coded timeouts to secs_to_jiffies()Easwar Hariharan4-8/+10
We have several places where timeouts are open-coded as N (seconds) * HZ, but best practice is to use the utility functions from jiffies.h. Convert the timeouts to be compliant. This doesn't fix any bugs, it's a simple code improvement. Signed-off-by: Easwar Hariharan <eahariha@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/20241030-open-coded-timeouts-v3-2-9ba123facf88@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20241030-open-coded-timeouts-v3-2-9ba123facf88@linux.microsoft.com>