diff options
| author |   Paolo Bonzini <pbonzini@redhat.com> | 2021-03-25 14:05:11 -0400 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-04-01 05:14:19 -0400 |
| commit | c2c647f91aec192f45f0849c225f134183cf4e90 (patch) | |
| tree | 9e300bec50aef907eed3af159066e32870d6f4e2 /arch/x86/kvm/x86.c | |
| parent | Merge branch 'kvm-fix-svm-races' into kvm-master (diff) | |
| download | linux-dev-c2c647f91aec192f45f0849c225f134183cf4e90.tar.xz linux-dev-c2c647f91aec192f45f0849c225f134183cf4e90.zip | |
KVM: x86: reduce pvclock_gtod_sync_lock critical sections
There is no need to include changes to vcpu->requests into
the pvclock_gtod_sync_lock critical section. The changes to
the shared data structures (in pvclock_update_vm_gtod_copy)
already occur under the lock.
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to '')
| -rw-r--r-- | arch/x86/kvm/x86.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index f7d12fca397b..2301623d3c53 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2561,10 +2561,12 @@ static void kvm_gen_update_masterclock(struct kvm *kvm) kvm_hv_invalidate_tsc_page(kvm); - spin_lock(&ka->pvclock_gtod_sync_lock); kvm_make_mclock_inprogress_request(kvm); + /* no guest entries from this point */ + spin_lock(&ka->pvclock_gtod_sync_lock); pvclock_update_vm_gtod_copy(kvm); + spin_unlock(&ka->pvclock_gtod_sync_lock); kvm_for_each_vcpu(i, vcpu, kvm) kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu); @@ -2572,8 +2574,6 @@ static void kvm_gen_update_masterclock(struct kvm *kvm) /* guest entries allowed */ kvm_for_each_vcpu(i, vcpu, kvm) kvm_clear_request(KVM_REQ_MCLOCK_INPROGRESS, vcpu); - - spin_unlock(&ka->pvclock_gtod_sync_lock); #endif } @@ -7739,16 +7739,14 @@ static void kvm_hyperv_tsc_notifier(void) struct kvm_arch *ka = &kvm->arch; spin_lock(&ka->pvclock_gtod_sync_lock); - pvclock_update_vm_gtod_copy(kvm); + spin_unlock(&ka->pvclock_gtod_sync_lock); kvm_for_each_vcpu(cpu, vcpu, kvm) kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu); kvm_for_each_vcpu(cpu, vcpu, kvm) kvm_clear_request(KVM_REQ_MCLOCK_INPROGRESS, vcpu); - - spin_unlock(&ka->pvclock_gtod_sync_lock); } mutex_unlock(&kvm_lock); } |