From: Vitaly Kuznetsov <[email protected]> commit 99c221796a810055974b54c02e8f53297e48d146 upstream.
I noticed that apic test from kvm-unit-tests always hangs on my EPYC 7401P, the hanging test nmi-after-sti is trying to deliver 30000 NMIs and tracing shows that we're sometimes able to deliver a few but never all. When we're trying to inject an NMI we may fail to do so immediately for various reasons, however, we still need to inject it so enable_nmi_window() arms nmi_singlestep mode. #DB occurs as expected, but we're not checking for pending NMIs before entering the guest and unless there's a different event to process, the NMI will never get delivered. Make KVM_REQ_EVENT request on the vCPU from db_interception() to make sure pending NMIs are checked and possibly injected. Signed-off-by: Vitaly Kuznetsov <[email protected]> Cc: [email protected] Signed-off-by: Paolo Bonzini <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/x86/kvm/svm.c | 3 +++ 1 file changed, 3 insertions(+) --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -2211,6 +2211,7 @@ static int pf_interception(struct vcpu_s static int db_interception(struct vcpu_svm *svm) { struct kvm_run *kvm_run = svm->vcpu.run; + struct kvm_vcpu *vcpu = &svm->vcpu; if (!(svm->vcpu.guest_debug & (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP)) && @@ -2221,6 +2222,8 @@ static int db_interception(struct vcpu_s if (svm->nmi_singlestep) { disable_nmi_singlestep(svm); + /* Make sure we check for pending NMIs upon entry */ + kvm_make_request(KVM_REQ_EVENT, vcpu); } if (svm->vcpu.guest_debug &
