From 55934c0bd3bb232a9cf902820dd63ad18ed65e49 Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Mon, 15 Dec 2008 13:52:10 +0100 Subject: KVM: VMX: Allow single-stepping when uninterruptible When single-stepping over STI and MOV SS, we must clear the corresponding interruptibility bits in the guest state. Otherwise vmentry fails as it then expects bit 14 (BS) in pending debug exceptions being set, but that's not correct for the guest debugging case. Note that clearing those bits is safe as we check for interruptibility based on the original state and do not inject interrupts or NMIs if guest interruptibility was blocked. Signed-off-by: Jan Kiszka Signed-off-by: Avi Kivity --- arch/x86/kvm/vmx.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index f55690ddb3a..c776868ffe4 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2478,6 +2478,11 @@ static void do_interrupt_requests(struct kvm_vcpu *vcpu, { vmx_update_window_states(vcpu); + if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) + vmcs_clear_bits(GUEST_INTERRUPTIBILITY_INFO, + GUEST_INTR_STATE_STI | + GUEST_INTR_STATE_MOV_SS); + if (vcpu->arch.nmi_pending && !vcpu->arch.nmi_injected) { if (vcpu->arch.interrupt.pending) { enable_nmi_window(vcpu); @@ -3244,6 +3249,11 @@ static void vmx_intr_assist(struct kvm_vcpu *vcpu) vmx_update_window_states(vcpu); + if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) + vmcs_clear_bits(GUEST_INTERRUPTIBILITY_INFO, + GUEST_INTR_STATE_STI | + GUEST_INTR_STATE_MOV_SS); + if (vcpu->arch.nmi_pending && !vcpu->arch.nmi_injected) { if (vcpu->arch.interrupt.pending) { enable_nmi_window(vcpu); -- cgit v1.2.3