From 787ff73637bbf34ef276cb04a127b421de71cc43 Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Mon, 18 May 2009 11:44:06 +0300 Subject: [PATCH] KVM: Drop interrupt shadow when single stepping should be done only on VMX The problem exists only on VMX. Also currently we skip this step if there is pending exception. The patch fixes this too. Signed-off-by: Gleb Natapov Signed-off-by: Avi Kivity --- arch/x86/kvm/vmx.c | 8 ++++++++ arch/x86/kvm/x86.c | 3 --- 2 files changed, 8 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index c87c93fd129a..c14bffc8c1f9 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3453,6 +3453,14 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) if (test_bit(VCPU_REGS_RIP, (unsigned long *)&vcpu->arch.regs_dirty)) vmcs_writel(GUEST_RIP, vcpu->arch.regs[VCPU_REGS_RIP]); + /* 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. */ + if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) + vmx_set_interrupt_shadow(vcpu, 0); + /* * Loading guest fpu may have cleared host cr0.ts */ diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 25a1c5739dfc..f0642396783f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3361,9 +3361,6 @@ static void update_cr8_intercept(struct kvm_vcpu *vcpu) static void inject_pending_irq(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) { - if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) - kvm_x86_ops->set_interrupt_shadow(vcpu, 0); - /* try to reinject previous events if any */ if (vcpu->arch.nmi_injected) { kvm_x86_ops->set_nmi(vcpu); -- 2.34.1