From 47a66eed99e6f231f4a1d261a9d493f4eee94829 Mon Sep 17 00:00:00 2001 From: ZhuangYanying <ann.zhuangyanying@huawei.com> Date: Fri, 26 May 2017 13:16:48 +0800 Subject: [PATCH] KVM: x86: Fix nmi injection failure when vcpu got blocked When spin_lock_irqsave() deadlock occurs inside the guest, vcpu threads, other than the lock-holding one, would enter into S state because of pvspinlock. Then inject NMI via libvirt API "inject-nmi", the NMI could not be injected into vm. The reason is: 1 It sets nmi_queued to 1 when calling ioctl KVM_NMI in qemu, and sets cpu->kvm_vcpu_dirty to true in do_inject_external_nmi() meanwhile. 2 It sets nmi_queued to 0 in process_nmi(), before entering guest, because cpu->kvm_vcpu_dirty is true. It's not enough just to check nmi_queued to decide whether to stay in vcpu_block() or not. NMI should be injected immediately at any situation. Add checking nmi_pending, and testing KVM_REQ_NMI replaces nmi_queued in vm_vcpu_has_events(). Do the same change for SMIs. Signed-off-by: Zhuang Yanying <ann.zhuangyanying@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- arch/x86/kvm/x86.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 02363e37d4a6..a2cd0997343c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8394,10 +8394,13 @@ static inline bool kvm_vcpu_has_events(struct kvm_vcpu *vcpu) if (vcpu->arch.pv.pv_unhalted) return true; - if (atomic_read(&vcpu->arch.nmi_queued)) + if (kvm_test_request(KVM_REQ_NMI, vcpu) || + (vcpu->arch.nmi_pending && + kvm_x86_ops->nmi_allowed(vcpu))) return true; - if (kvm_test_request(KVM_REQ_SMI, vcpu)) + if (kvm_test_request(KVM_REQ_SMI, vcpu) || + (vcpu->arch.smi_pending && !is_smm(vcpu))) return true; if (kvm_arch_interrupt_allowed(vcpu) && -- GitLab