From: ZhuangYanying <ann.zhuangyanying@xxxxxxxxxx> 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 KVM_REQ_NMI request plus with nmi_queued in vm_vcpu_has_events(). Signed-off-by: Zhuang Yanying <ann.zhuangyanying@xxxxxxxxxx> --- arch/x86/kvm/x86.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 02363e3..2d15708 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8394,7 +8394,9 @@ 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) || + atomic_read(&vcpu->arch.nmi_queued)) && + kvm_x86_ops->nmi_allowed(vcpu)) return true; if (kvm_test_request(KVM_REQ_SMI, vcpu)) -- 1.8.3.1
