On Wed, Apr 08, 2009 at 01:57:32PM -0400, Glauber Costa wrote: > 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); remove_interrupt_shadow or unblock_interrupt_shadow would be better names IMHO. > 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 -- Gleb. -- 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
