While in real mode, sti does not block interrupts from the subsequent instruction. This is stated at Intel SDM Volume 2b, page 4-432
Without this patch, I cannot boot gpxe option roms at vmx machines. This is described at https://bugzilla.redhat.com/show_bug.cgi?id=494469 Signed-off-by: Glauber Costa <[email protected]> --- arch/x86/kvm/vmx.c | 9 +++++---- 1 files changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index c6997c0..51e0b8a 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2490,18 +2490,19 @@ static void vmx_inject_nmi(struct kvm_vcpu *vcpu) static void vmx_update_window_states(struct kvm_vcpu *vcpu) { u32 guest_intr = vmcs_read32(GUEST_INTERRUPTIBILITY_INFO); + int rmode = vcpu->arch.rmode.active; vcpu->arch.nmi_window_open = - !(guest_intr & (GUEST_INTR_STATE_STI | - GUEST_INTR_STATE_MOV_SS | + (rmode || !(guest_intr & GUEST_INTR_STATE_STI)) && + !(guest_intr & (GUEST_INTR_STATE_MOV_SS | GUEST_INTR_STATE_NMI)); if (!cpu_has_virtual_nmis() && to_vmx(vcpu)->soft_vnmi_blocked) vcpu->arch.nmi_window_open = 0; vcpu->arch.interrupt_window_open = ((vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_IF) && - !(guest_intr & (GUEST_INTR_STATE_STI | - GUEST_INTR_STATE_MOV_SS))); + (rmode || !(guest_intr & GUEST_INTR_STATE_STI)) && + !(guest_intr & GUEST_INTR_STATE_MOV_SS)); } static int vmx_interrupt_allowed(struct kvm_vcpu *vcpu) -- 1.6.2 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
