KVM: x86: Pending interrupt may be delivered after INIT

We encountered a scenario in which after an INIT is delivered, a pending
interrupt is delivered, although it was sent before the INIT.  As the SDM
states in section 10.4.7.1, the ISR and the IRR should be cleared after INIT as
KVM does.  This also means that pending interrupts should be cleared.  This
patch clears upon reset (and INIT) the pending interrupts; and at the same
occassion clears the pending exceptions, since they may cause a similar issue.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f056f855f8e6612a3d6c3a38bb6d6a5d79e10cbb..b13f3a39ebecf2fcfbd84ac73aa414ae825c8a6f 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6845,6 +6845,8 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu)
        atomic_set(&vcpu->arch.nmi_queued, 0);
        vcpu->arch.nmi_pending = 0;
        vcpu->arch.nmi_injected = false;
+       kvm_clear_interrupt_queue(vcpu);
+       kvm_clear_exception_queue(vcpu);
 
        memset(vcpu->arch.db, 0, sizeof(vcpu->arch.db));
        vcpu->arch.dr6 = DR6_FIXED_1;