we currently unblock shadow interrupt state when we skip an instruction, but failing to do so when we actually emulate one. This blocks interrupts in key instruction blocks, in particular sti; hlt; sequences 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 <glommer@xxxxxxxxxx> CC: H. Peter Anvin <hpa@xxxxxxxxx> CC: Avi Kivity <avi@xxxxxxxxxx> --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/svm.c | 12 ++++++++++-- arch/x86/kvm/vmx.c | 29 +++++++++++++++++++---------- arch/x86/kvm/x86.c | 2 ++ 4 files changed, 32 insertions(+), 12 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 3fc4623..0890a6e 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -513,6 +513,7 @@ struct kvm_x86_ops { void (*run)(struct kvm_vcpu *vcpu, struct kvm_run *run); int (*handle_exit)(struct kvm_run *run, struct kvm_vcpu *vcpu); void (*skip_emulated_instruction)(struct kvm_vcpu *vcpu); + void (*block_interrupt_shadow)(struct kvm_vcpu *vcpu); void (*patch_hypercall)(struct kvm_vcpu *vcpu, unsigned char *hypercall_addr); int (*get_irq)(struct kvm_vcpu *vcpu); diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 3ffb695..d303e86 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -210,6 +210,14 @@ static int is_external_interrupt(u32 info) return info == (SVM_EVTINJ_VALID | SVM_EVTINJ_TYPE_INTR); } +static void svm_block_interrupt_shadow(struct kvm_vcpu *vcpu) +{ + struct vcpu_svm *svm = to_svm(vcpu); + + svm->vmcb->control.int_state &= ~SVM_INTERRUPT_SHADOW_MASK; + vcpu->arch.interrupt_window_open = (svm->vcpu.arch.hflags & HF_GIF_MASK); +} + static void skip_emulated_instruction(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); @@ -223,9 +231,8 @@ static void skip_emulated_instruction(struct kvm_vcpu *vcpu) __func__, kvm_rip_read(vcpu), svm->next_rip); kvm_rip_write(vcpu, svm->next_rip); - svm->vmcb->control.int_state &= ~SVM_INTERRUPT_SHADOW_MASK; - vcpu->arch.interrupt_window_open = (svm->vcpu.arch.hflags & HF_GIF_MASK); + svm_block_interrupt_shadow(vcpu); } static int has_svm(void) @@ -2660,6 +2667,7 @@ static struct kvm_x86_ops svm_x86_ops = { .run = svm_vcpu_run, .handle_exit = handle_exit, .skip_emulated_instruction = skip_emulated_instruction, + .block_interrupt_shadow = svm_block_interrupt_shadow, .patch_hypercall = svm_patch_hypercall, .get_irq = svm_get_irq, .set_irq = svm_set_irq, diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index c6997c0..cee38e4 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -736,26 +736,34 @@ static void vmx_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags) vmcs_writel(GUEST_RFLAGS, rflags); } +static void vmx_block_interrupt_shadow(struct kvm_vcpu *vcpu) +{ + /* + * We emulated an instruction, so temporary interrupt blocking + * should be removed, if set. + */ + u32 interruptibility = vmcs_read32(GUEST_INTERRUPTIBILITY_INFO); + u32 interruptibility_mask = ((GUEST_INTR_STATE_STI | GUEST_INTR_STATE_MOV_SS)); + + if (interruptibility & interruptibility_mask) + vmcs_write32(GUEST_INTERRUPTIBILITY_INFO, + interruptibility & ~interruptibility_mask); + vcpu->arch.interrupt_window_open = 1; +} + static void skip_emulated_instruction(struct kvm_vcpu *vcpu) { unsigned long rip; - u32 interruptibility; rip = kvm_rip_read(vcpu); rip += vmcs_read32(VM_EXIT_INSTRUCTION_LEN); kvm_rip_write(vcpu, rip); - /* - * We emulated an instruction, so temporary interrupt blocking - * should be removed, if set. - */ - interruptibility = vmcs_read32(GUEST_INTERRUPTIBILITY_INFO); - if (interruptibility & 3) - vmcs_write32(GUEST_INTERRUPTIBILITY_INFO, - interruptibility & ~3); - vcpu->arch.interrupt_window_open = 1; + /* skipping an emulated instruction also counts */ + vmx_block_interrupt_shadow(vcpu); } + static void vmx_queue_exception(struct kvm_vcpu *vcpu, unsigned nr, bool has_error_code, u32 error_code) { @@ -3727,6 +3735,7 @@ static struct kvm_x86_ops vmx_x86_ops = { .run = vmx_vcpu_run, .handle_exit = vmx_handle_exit, .skip_emulated_instruction = skip_emulated_instruction, + .block_interrupt_shadow = vmx_block_interrupt_shadow, .patch_hypercall = vmx_patch_hypercall, .get_irq = vmx_get_irq, .set_irq = vmx_inject_irq, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 0bb4131..8fa83b9 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2414,6 +2414,8 @@ int emulate_instruction(struct kvm_vcpu *vcpu, r = x86_emulate_insn(&vcpu->arch.emulate_ctxt, &emulate_ops); + kvm_x86_ops->block_interrupt_shadow(vcpu); + if (vcpu->arch.pio.string) return EMULATE_DO_MMIO; -- 1.5.6.6 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
