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authorLinus Torvalds <torvalds@linux-foundation.org>2026-06-16 05:57:30 +0530
committerLinus Torvalds <torvalds@linux-foundation.org>2026-06-16 05:57:30 +0530
commitc61f479852493fd2cf5ca754e42ac272b1e2d2c5 (patch)
tree8f99e3a4c0fbecc54eb2f0631d0c58e344c5c26c /arch
parent97cc7dc16aaee163e15173009c063fc9cd42b5ff (diff)
parent9d8460a1c7a6b0f2dc6302e5d0f31d4e8c2a7913 (diff)
downloadath-c61f479852493fd2cf5ca754e42ac272b1e2d2c5.tar.gz
Merge tag 'x86_sev_for_v7.2_rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip
Pull x86 SEV updates from Borislav Petkov: - Remove redundant GHCB initialization guards in the SEV page state and SVSM call paths now that the GHCB helpers handle early-boot fallback internally - Skip SNP initialization in the CCP driver immediately when the preparation step fails rather than proceeding to an operation that will certainly fail - Abort SNP preparation and return an error when not all CPUs are online, since the firmware enforces that every CPU enables SNP and will fail init if not - Simplify the VMM communication exception entry path by replacing separate kernel and user mode macros with a single handler that dispatches based on the current privilege level * tag 'x86_sev_for_v7.2_rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: x86/sev: Remove redundant ghcbs_initialized checks around __sev_{get,put}_ghcb() crypto/ccp: Skip SNP_INIT if preparation fails x86/sev: Do not initialize SNP if missing CPUs x86/entry: Zap the #VC entry user and kernel macros
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/coco/sev/core.c8
-rw-r--r--arch/x86/coco/sev/internal.h3
-rw-r--r--arch/x86/coco/sev/noinstr.c4
-rw-r--r--arch/x86/coco/sev/svsm.c10
-rw-r--r--arch/x86/coco/sev/vc-handle.c12
-rw-r--r--arch/x86/entry/entry_64.S4
-rw-r--r--arch/x86/entry/entry_fred.c10
-rw-r--r--arch/x86/include/asm/idtentry.h29
-rw-r--r--arch/x86/include/asm/sev.h4
-rw-r--r--arch/x86/virt/svm/sev.c18
10 files changed, 43 insertions, 59 deletions
diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c
index 7ed3da998489d..ecd77d3217f3c 100644
--- a/arch/x86/coco/sev/core.c
+++ b/arch/x86/coco/sev/core.c
@@ -367,17 +367,13 @@ static unsigned long __set_pages_state(struct snp_psc_desc *data, unsigned long
local_irq_save(flags);
- if (sev_cfg.ghcbs_initialized)
- ghcb = __sev_get_ghcb(&state);
- else
- ghcb = boot_ghcb;
+ ghcb = __sev_get_ghcb(&state);
/* Invoke the hypervisor to perform the page state changes */
if (!ghcb || vmgexit_psc(ghcb, data))
sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC);
- if (sev_cfg.ghcbs_initialized)
- __sev_put_ghcb(&state);
+ __sev_put_ghcb(&state);
local_irq_restore(flags);
diff --git a/arch/x86/coco/sev/internal.h b/arch/x86/coco/sev/internal.h
index b1d0c66a651a6..b9632c0fc3916 100644
--- a/arch/x86/coco/sev/internal.h
+++ b/arch/x86/coco/sev/internal.h
@@ -70,6 +70,9 @@ void svsm_pval_pages(struct snp_psc_desc *desc);
int svsm_perform_call_protocol(struct svsm_call *call);
bool snp_svsm_vtpm_probe(void);
+noinstr void kernel_exc_vmm_communication(struct pt_regs *regs, unsigned long error_code);
+noinstr void user_exc_vmm_communication(struct pt_regs *regs, unsigned long error_code);
+
static inline u64 sev_es_rd_ghcb_msr(void)
{
return native_rdmsrq(MSR_AMD64_SEV_ES_GHCB);
diff --git a/arch/x86/coco/sev/noinstr.c b/arch/x86/coco/sev/noinstr.c
index 5afd663a1c217..e1e03f12fc7bb 100644
--- a/arch/x86/coco/sev/noinstr.c
+++ b/arch/x86/coco/sev/noinstr.c
@@ -121,8 +121,10 @@ noinstr struct ghcb *__sev_get_ghcb(struct ghcb_state *state)
WARN_ON(!irqs_disabled());
- if (!sev_cfg.ghcbs_initialized)
+ if (!sev_cfg.ghcbs_initialized) {
+ state->ghcb = NULL;
return boot_ghcb;
+ }
data = this_cpu_read(runtime_data);
ghcb = &data->ghcb_page;
diff --git a/arch/x86/coco/sev/svsm.c b/arch/x86/coco/sev/svsm.c
index 2acf4a76afe7a..916d62cd17dc7 100644
--- a/arch/x86/coco/sev/svsm.c
+++ b/arch/x86/coco/sev/svsm.c
@@ -74,20 +74,14 @@ int svsm_perform_call_protocol(struct svsm_call *call)
flags = native_local_irq_save();
- if (sev_cfg.ghcbs_initialized)
- ghcb = __sev_get_ghcb(&state);
- else if (boot_ghcb)
- ghcb = boot_ghcb;
- else
- ghcb = NULL;
+ ghcb = __sev_get_ghcb(&state);
do {
ret = ghcb ? svsm_perform_ghcb_protocol(ghcb, call)
: __pi_svsm_perform_msr_protocol(call);
} while (ret == -EAGAIN);
- if (sev_cfg.ghcbs_initialized)
- __sev_put_ghcb(&state);
+ __sev_put_ghcb(&state);
native_local_irq_restore(flags);
diff --git a/arch/x86/coco/sev/vc-handle.c b/arch/x86/coco/sev/vc-handle.c
index d98b5c08ef00d..96b62b49b2b53 100644
--- a/arch/x86/coco/sev/vc-handle.c
+++ b/arch/x86/coco/sev/vc-handle.c
@@ -954,7 +954,7 @@ static __always_inline bool vc_is_db(unsigned long error_code)
* Runtime #VC exception handler when raised from kernel mode. Runs in NMI mode
* and will panic when an error happens.
*/
-DEFINE_IDTENTRY_VC_KERNEL(exc_vmm_communication)
+noinstr void kernel_exc_vmm_communication(struct pt_regs *regs, unsigned long error_code)
{
irqentry_state_t irq_state;
@@ -1006,7 +1006,7 @@ DEFINE_IDTENTRY_VC_KERNEL(exc_vmm_communication)
* Runtime #VC exception handler when raised from user mode. Runs in IRQ mode
* and will kill the current task with SIGBUS when an error happens.
*/
-DEFINE_IDTENTRY_VC_USER(exc_vmm_communication)
+noinstr void user_exc_vmm_communication(struct pt_regs *regs, unsigned long error_code)
{
/*
* Handle #DB before calling into !noinstr code to avoid recursive #DB.
@@ -1032,6 +1032,14 @@ DEFINE_IDTENTRY_VC_USER(exc_vmm_communication)
irqentry_exit_to_user_mode(regs);
}
+DEFINE_IDTENTRY_RAW_ERRORCODE(exc_vmm_communication)
+{
+ if (user_mode(regs))
+ return user_exc_vmm_communication(regs, error_code);
+ else
+ return kernel_exc_vmm_communication(regs, error_code);
+}
+
bool __init handle_vc_boot_ghcb(struct pt_regs *regs)
{
unsigned long exit_code = regs->orig_ax;
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 42447b1e1dffa..c6d996593f329 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -492,7 +492,7 @@ SYM_CODE_START(\asmsym)
movq %rsp, %rdi /* pt_regs pointer */
- call kernel_\cfunc
+ call \cfunc
/*
* No need to switch back to the IST stack. The current stack is either
@@ -503,7 +503,7 @@ SYM_CODE_START(\asmsym)
/* Switch to the regular task stack */
.Lfrom_usermode_switch_stack_\@:
- idtentry_body user_\cfunc, has_error_code=1
+ idtentry_body \cfunc, has_error_code=1
_ASM_NOKPROBE(\asmsym)
SYM_CODE_END(\asmsym)
diff --git a/arch/x86/entry/entry_fred.c b/arch/x86/entry/entry_fred.c
index fbe2d10dd737d..fb3594ddf731f 100644
--- a/arch/x86/entry/entry_fred.c
+++ b/arch/x86/entry/entry_fred.c
@@ -177,16 +177,6 @@ static noinstr void fred_extint(struct pt_regs *regs)
}
}
-#ifdef CONFIG_AMD_MEM_ENCRYPT
-noinstr void exc_vmm_communication(struct pt_regs *regs, unsigned long error_code)
-{
- if (user_mode(regs))
- return user_exc_vmm_communication(regs, error_code);
- else
- return kernel_exc_vmm_communication(regs, error_code);
-}
-#endif
-
static noinstr void fred_hwexc(struct pt_regs *regs, unsigned long error_code)
{
/* Optimize for #PF. That's the only exception which matters performance wise */
diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 42bf6a58ec368..20f5487024042 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -340,17 +340,14 @@ static __always_inline void __##func(struct pt_regs *regs)
__visible void noist_##func(struct pt_regs *regs)
/**
- * DECLARE_IDTENTRY_VC - Declare functions for the VC entry point
+ * DECLARE_IDTENTRY_VC - Declare a function for the VC entry point
* @vector: Vector number (ignored for C)
* @func: Function name of the entry point
*
- * Maps to DECLARE_IDTENTRY_RAW_ERRORCODE, but declares also the
- * safe_stack C handler.
+ * Maps to DECLARE_IDTENTRY_RAW_ERRORCODE.
*/
#define DECLARE_IDTENTRY_VC(vector, func) \
- DECLARE_IDTENTRY_RAW_ERRORCODE(vector, func); \
- __visible noinstr void kernel_##func(struct pt_regs *regs, unsigned long error_code); \
- __visible noinstr void user_##func(struct pt_regs *regs, unsigned long error_code)
+ DECLARE_IDTENTRY_RAW_ERRORCODE(vector, func);
/**
* DEFINE_IDTENTRY_IST - Emit code for IST entry points
@@ -391,26 +388,6 @@ static __always_inline void __##func(struct pt_regs *regs)
#define DEFINE_IDTENTRY_DF(func) \
DEFINE_IDTENTRY_RAW_ERRORCODE(func)
-/**
- * DEFINE_IDTENTRY_VC_KERNEL - Emit code for VMM communication handler
- * when raised from kernel mode
- * @func: Function name of the entry point
- *
- * Maps to DEFINE_IDTENTRY_RAW_ERRORCODE
- */
-#define DEFINE_IDTENTRY_VC_KERNEL(func) \
- DEFINE_IDTENTRY_RAW_ERRORCODE(kernel_##func)
-
-/**
- * DEFINE_IDTENTRY_VC_USER - Emit code for VMM communication handler
- * when raised from user mode
- * @func: Function name of the entry point
- *
- * Maps to DEFINE_IDTENTRY_RAW_ERRORCODE
- */
-#define DEFINE_IDTENTRY_VC_USER(func) \
- DEFINE_IDTENTRY_RAW_ERRORCODE(user_##func)
-
#else /* CONFIG_X86_64 */
/**
diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index 09e605c85de4c..594cfa19cbd4b 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -661,7 +661,7 @@ static inline void snp_leak_pages(u64 pfn, unsigned int pages)
{
__snp_leak_pages(pfn, pages, true);
}
-void snp_prepare(void);
+int snp_prepare(void);
void snp_shutdown(void);
#else
static inline bool snp_probe_rmptable_info(void) { return false; }
@@ -679,7 +679,7 @@ static inline void __snp_leak_pages(u64 pfn, unsigned int npages, bool dump_rmp)
static inline void snp_leak_pages(u64 pfn, unsigned int npages) {}
static inline void kdump_sev_callback(void) { }
static inline void snp_fixup_e820_tables(void) {}
-static inline void snp_prepare(void) {}
+static inline int snp_prepare(void) { return -ENODEV; }
static inline void snp_shutdown(void) {}
#endif
diff --git a/arch/x86/virt/svm/sev.c b/arch/x86/virt/svm/sev.c
index 41f76f15caa13..8bcdce98f6dce 100644
--- a/arch/x86/virt/svm/sev.c
+++ b/arch/x86/virt/svm/sev.c
@@ -511,8 +511,9 @@ static void clear_hsave_pa(void *arg)
wrmsrq(MSR_VM_HSAVE_PA, 0);
}
-void snp_prepare(void)
+int snp_prepare(void)
{
+ int ret;
u64 val;
/*
@@ -521,12 +522,20 @@ void snp_prepare(void)
*/
rdmsrq(MSR_AMD64_SYSCFG, val);
if (val & MSR_AMD64_SYSCFG_SNP_EN)
- return;
+ return 0;
clear_rmp();
cpus_read_lock();
+ if (!cpumask_equal(cpu_online_mask, cpu_present_mask)) {
+ ret = -EOPNOTSUPP;
+ pr_warn("SNP init failed: not all CPUs online. (%*pbl online <-> %*pbl present masks).\n",
+ cpumask_pr_args(cpu_online_mask),
+ cpumask_pr_args(cpu_present_mask));
+ goto unlock;
+ }
+
/*
* MtrrFixDramModEn is not shared between threads on a core,
* therefore it must be set on all CPUs prior to enabling SNP.
@@ -537,7 +546,12 @@ void snp_prepare(void)
/* SNP_INIT requires MSR_VM_HSAVE_PA to be cleared on all CPUs. */
on_each_cpu(clear_hsave_pa, NULL, 1);
+ ret = 0;
+
+unlock:
cpus_read_unlock();
+
+ return ret;
}
EXPORT_SYMBOL_FOR_MODULES(snp_prepare, "ccp");
generated by cgit 1.3-korg (git 2.53.0) at 2026-07-01 13:56:02 +0000