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| author | Paolo Bonzini <pbonzini@redhat.com> | 2025-05-27 12:17:06 -0400 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2025-05-28 06:29:17 -0400 |
| commit | 8e86e73626527e5a69bf5263d6bbe9c2a86b4319 (patch) | |
| tree | d56a6bc701bded71bf3befc233df4f73bd0589a9 /virt | |
| parent | 4e02d4f9734fa55e3eb18be9b759cd42d93497ec (diff) | |
| parent | 4dbe28c0fabd69842890ba38f185b96664cba26a (diff) | |
| download | linux-8e86e73626527e5a69bf5263d6bbe9c2a86b4319.tar.gz | |
Merge branch 'kvm-lockdep-common' into HEAD
Introduce new mutex locking functions mutex_trylock_nest_lock() and
mutex_lock_killable_nest_lock() and use them to clean up locking
of all vCPUs for a VM.
For x86, this removes some complex code that was used instead
of lockdep's "nest_lock" feature.
For ARM and RISC-V, this removes a lockdep warning when the VM is
configured to have more than MAX_LOCK_DEPTH vCPUs, and removes a fair
amount of duplicate code by sharing the logic across all architectures.
Signed-off-by: Paolo BOnzini <pbonzini@redhat.com>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/kvm_main.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index b24db92e98f3f1..eec82775c5bfbe 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1368,6 +1368,65 @@ static int kvm_vm_release(struct inode *inode, struct file *filp) return 0; } +int kvm_trylock_all_vcpus(struct kvm *kvm) +{ + struct kvm_vcpu *vcpu; + unsigned long i, j; + + lockdep_assert_held(&kvm->lock); + + kvm_for_each_vcpu(i, vcpu, kvm) + if (!mutex_trylock_nest_lock(&vcpu->mutex, &kvm->lock)) + goto out_unlock; + return 0; + +out_unlock: + kvm_for_each_vcpu(j, vcpu, kvm) { + if (i == j) + break; + mutex_unlock(&vcpu->mutex); + } + return -EINTR; +} +EXPORT_SYMBOL_GPL(kvm_trylock_all_vcpus); + +int kvm_lock_all_vcpus(struct kvm *kvm) +{ + struct kvm_vcpu *vcpu; + unsigned long i, j; + int r; + + lockdep_assert_held(&kvm->lock); + + kvm_for_each_vcpu(i, vcpu, kvm) { + r = mutex_lock_killable_nest_lock(&vcpu->mutex, &kvm->lock); + if (r) + goto out_unlock; + } + return 0; + +out_unlock: + kvm_for_each_vcpu(j, vcpu, kvm) { + if (i == j) + break; + mutex_unlock(&vcpu->mutex); + } + return r; +} +EXPORT_SYMBOL_GPL(kvm_lock_all_vcpus); + +void kvm_unlock_all_vcpus(struct kvm *kvm) +{ + struct kvm_vcpu *vcpu; + unsigned long i; + + lockdep_assert_held(&kvm->lock); + + kvm_for_each_vcpu(i, vcpu, kvm) + mutex_unlock(&vcpu->mutex); +} +EXPORT_SYMBOL_GPL(kvm_unlock_all_vcpus); + /* * Allocation size is twice as large as the actual dirty bitmap size. * See kvm_vm_ioctl_get_dirty_log() why this is needed. |