diff options
Diffstat (limited to 'arch/x86/kvm/svm/avic.c')
| -rw-r--r-- | arch/x86/kvm/svm/avic.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index 8f9af7b7dbbe..0e5b49294086 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -293,7 +293,7 @@ static void avic_kick_target_vcpus(struct kvm *kvm, struct kvm_lapic *source, u32 icrl, u32 icrh) { struct kvm_vcpu *vcpu; - int i; + unsigned long i; kvm_for_each_vcpu(i, vcpu, kvm) { bool m = kvm_apic_match_dest(vcpu, source, @@ -675,10 +675,18 @@ int svm_deliver_avic_intr(struct kvm_vcpu *vcpu, int vec) smp_mb__after_atomic(); if (avic_vcpu_is_running(vcpu)) { - int cpuid = vcpu->cpu; + int cpu = READ_ONCE(vcpu->cpu); - if (cpuid != get_cpu()) - wrmsrl(SVM_AVIC_DOORBELL, kvm_cpu_get_apicid(cpuid)); + /* + * Note, the vCPU could get migrated to a different pCPU at any + * point, which could result in signalling the wrong/previous + * pCPU. But if that happens the vCPU is guaranteed to do a + * VMRUN (after being migrated) and thus will process pending + * interrupts, i.e. a doorbell is not needed (and the spurious + * one is harmless). + */ + if (cpu != get_cpu()) + wrmsrl(SVM_AVIC_DOORBELL, kvm_cpu_get_apicid(cpu)); put_cpu(); } else kvm_vcpu_wake_up(vcpu); |