diff mbox

[2/2] Interrupt unhalts vcpu when it shouldn't

Message ID 20090323101211.25798.89641.stgit@dhcp-1-237.tlv.redhat.com (mailing list archive)
State Accepted
Headers show

Commit Message

Gleb Natapov March 23, 2009, 10:12 a.m. UTC 
kvm_vcpu_block() unhalts vpu on an interrupt/timer without checking
if interrupt window is actually opened.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
---

 arch/ia64/kvm/kvm-ia64.c        |    6 ++++++
 arch/powerpc/kvm/powerpc.c      |    6 ++++++
 arch/s390/kvm/interrupt.c       |    6 ++++++
 arch/x86/include/asm/kvm_host.h |    2 +-
 arch/x86/kvm/svm.c              |   10 ++++++++++
 arch/x86/kvm/vmx.c              |    8 +++++++-
 arch/x86/kvm/x86.c              |    5 +++++
 include/linux/kvm_host.h        |    1 +
 virt/kvm/kvm_main.c             |    3 ++-
 9 files changed, 44 insertions(+), 3 deletions(-)


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Comments

Avi Kivity March 23, 2009, 2:31 p.m. UTC | #1 
Gleb Natapov wrote:
> kvm_vcpu_block() unhalts vpu on an interrupt/timer without checking
> if interrupt window is actually opened.
>
>  
> +static int svm_interrupt_allowed(struct kvm_vcpu *vcpu)
> +{
> +	struct vcpu_svm *svm = to_svm(vcpu);
> +	struct vmcb *vmcb = svm->vmcb;
> +	return (vmcb->save.rflags & X86_EFLAGS_IF) && 
> +		!(vmcb->control.int_state & SVM_INTERRUPT_SHADOW_MASK) &&
> +		(svm->vcpu.arch.hflags & HF_GIF_MASK);
> +}
> +
>  
> +static int vmx_interrupt_allowed(struct kvm_vcpu *vcpu)
> +{
> +	vmx_update_window_states(vcpu);
> +	return vcpu->arch.interrupt_window_open;
> +}
> +
>  static void kvm_do_inject_irq(struct kvm_vcpu *vcpu)
>  }
> +
> +int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu)
> +{
> +	return kvm_x86_ops->interrupt_allowed(vcpu);
> +}
>   

If the guest enables interrupts but sets tpr/cr8 to block interrupts, 
we'll spin (like we do now).

So I think this should be called kvm_arch_can_accept_interrupt() and 
take tpr into account.
Avi Kivity March 23, 2009, 3:17 p.m. UTC | #2 
Avi Kivity wrote:
> Gleb Natapov wrote:
>> kvm_vcpu_block() unhalts vpu on an interrupt/timer without checking
>> if interrupt window is actually opened.
>>
>>  
>> +static int svm_interrupt_allowed(struct kvm_vcpu *vcpu)
>> +{
>> +    struct vcpu_svm *svm = to_svm(vcpu);
>> +    struct vmcb *vmcb = svm->vmcb;
>> +    return (vmcb->save.rflags & X86_EFLAGS_IF) && +        
>> !(vmcb->control.int_state & SVM_INTERRUPT_SHADOW_MASK) &&
>> +        (svm->vcpu.arch.hflags & HF_GIF_MASK);
>> +}
>> +
>>  
>> +static int vmx_interrupt_allowed(struct kvm_vcpu *vcpu)
>> +{
>> +    vmx_update_window_states(vcpu);
>> +    return vcpu->arch.interrupt_window_open;
>> +}
>> +
>>  static void kvm_do_inject_irq(struct kvm_vcpu *vcpu)
>>  }
>> +
>> +int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu)
>> +{
>> +    return kvm_x86_ops->interrupt_allowed(vcpu);
>> +}
>>   
>
> If the guest enables interrupts but sets tpr/cr8 to block interrupts, 
> we'll spin (like we do now).
>
> So I think this should be called kvm_arch_can_accept_interrupt() and 
> take tpr into account.
>

kvm_cpu_has_interrupt() takes the tpr into account, so we're okay here.

Marcelo, Sheng?
Sheng Yang March 24, 2009, 5:24 a.m. UTC | #3 
On Monday 23 March 2009 23:17:42 Avi Kivity wrote:
> Avi Kivity wrote:
> > Gleb Natapov wrote:
> >> kvm_vcpu_block() unhalts vpu on an interrupt/timer without checking
> >> if interrupt window is actually opened.
> >>
> >>
> >> +static int svm_interrupt_allowed(struct kvm_vcpu *vcpu)
> >> +{
> >> +    struct vcpu_svm *svm = to_svm(vcpu);
> >> +    struct vmcb *vmcb = svm->vmcb;
> >> +    return (vmcb->save.rflags & X86_EFLAGS_IF) && +
> >> !(vmcb->control.int_state & SVM_INTERRUPT_SHADOW_MASK) &&
> >> +        (svm->vcpu.arch.hflags & HF_GIF_MASK);
> >> +}
> >> +
> >>
> >> +static int vmx_interrupt_allowed(struct kvm_vcpu *vcpu)
> >> +{
> >> +    vmx_update_window_states(vcpu);
> >> +    return vcpu->arch.interrupt_window_open;
> >> +}
> >> +
> >>  static void kvm_do_inject_irq(struct kvm_vcpu *vcpu)
> >>  }
> >> +
> >> +int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu)
> >> +{
> >> +    return kvm_x86_ops->interrupt_allowed(vcpu);
> >> +}
> >
> > If the guest enables interrupts but sets tpr/cr8 to block interrupts,
> > we'll spin (like we do now).
> >
> > So I think this should be called kvm_arch_can_accept_interrupt() and
> > take tpr into account.
>
> kvm_cpu_has_interrupt() takes the tpr into account, so we're okay here.
>
> Marcelo, Sheng?

Yes, looks good to me.
Avi Kivity March 24, 2009, 10:13 a.m. UTC | #4 
Gleb Natapov wrote:
> kvm_vcpu_block() unhalts vpu on an interrupt/timer without checking
> if interrupt window is actually opened.
>
>   

Applied both, thanks.
diff mbox

Patch

diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index db0b2a5..fdda799 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -1960,6 +1960,12 @@  int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
+int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu)
+{
+	/* do real check here */
+	return 1;
+}
+
 int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
 {
 	return vcpu->arch.timer_fired;
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 9057335..2cf915e 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -41,6 +41,12 @@  int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
 	return !!(v->arch.pending_exceptions);
 }
 
+int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu)
+{
+	/* do real check here */
+	return 1;
+}
+
 int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
 {
 	return !(v->arch.msr & MSR_WE);
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 0189356..4ed4c3a 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -318,6 +318,12 @@  int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu)
 	return rc;
 }
 
+int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu)
+{
+	/* do real check here */
+	return 1;
+}
+
 int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
 {
 	return 0;
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 4627627..8351c4d 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -521,7 +521,7 @@  struct kvm_x86_ops {
 	void (*inject_pending_irq)(struct kvm_vcpu *vcpu);
 	void (*inject_pending_vectors)(struct kvm_vcpu *vcpu,
 				       struct kvm_run *run);
-
+	int (*interrupt_allowed)(struct kvm_vcpu *vcpu);
 	int (*set_tss_addr)(struct kvm *kvm, unsigned int addr);
 	int (*get_tdp_level)(void);
 	int (*get_mt_mask_shift)(void);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index da23fd3..70c9dd3 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2285,6 +2285,15 @@  static void update_cr8_intercept(struct kvm_vcpu *vcpu)
 		vmcb->control.intercept_cr_write |= INTERCEPT_CR8_MASK;
 }
 
+static int svm_interrupt_allowed(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_svm *svm = to_svm(vcpu);
+	struct vmcb *vmcb = svm->vmcb;
+	return (vmcb->save.rflags & X86_EFLAGS_IF) && 
+		!(vmcb->control.int_state & SVM_INTERRUPT_SHADOW_MASK) &&
+		(svm->vcpu.arch.hflags & HF_GIF_MASK);
+}
+
 static void svm_intr_assist(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
@@ -2664,6 +2673,7 @@  static struct kvm_x86_ops svm_x86_ops = {
 	.exception_injected = svm_exception_injected,
 	.inject_pending_irq = svm_intr_assist,
 	.inject_pending_vectors = do_interrupt_requests,
+	.interrupt_allowed = svm_interrupt_allowed,
 
 	.set_tss_addr = svm_set_tss_addr,
 	.get_tdp_level = get_npt_level,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 5cf28df..dcc1036 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2489,6 +2489,12 @@  static void vmx_update_window_states(struct kvm_vcpu *vcpu)
 				 GUEST_INTR_STATE_MOV_SS)));
 }
 
+static int vmx_interrupt_allowed(struct kvm_vcpu *vcpu)
+{
+	vmx_update_window_states(vcpu);
+	return vcpu->arch.interrupt_window_open;
+}
+
 static void kvm_do_inject_irq(struct kvm_vcpu *vcpu)
 {
 	int word_index = __ffs(vcpu->arch.irq_summary);
@@ -3703,7 +3709,7 @@  static struct kvm_x86_ops vmx_x86_ops = {
 	.exception_injected = vmx_exception_injected,
 	.inject_pending_irq = vmx_intr_assist,
 	.inject_pending_vectors = do_interrupt_requests,
-
+	.interrupt_allowed = vmx_interrupt_allowed,
 	.set_tss_addr = vmx_set_tss_addr,
 	.get_tdp_level = get_ept_level,
 	.get_mt_mask_shift = vmx_get_mt_mask_shift,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index cfe8213..83822c0 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4465,3 +4465,8 @@  void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
 		smp_call_function_single(ipi_pcpu, vcpu_kick_intr, vcpu, 0);
 	put_cpu();
 }
+
+int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu)
+{
+	return kvm_x86_ops->interrupt_allowed(vcpu);
+}
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 11eb702..095ebb6 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -298,6 +298,7 @@  int kvm_arch_hardware_setup(void);
 void kvm_arch_hardware_unsetup(void);
 void kvm_arch_check_processor_compat(void *rtn);
 int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu);
+int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu);
 
 void kvm_free_physmem(struct kvm *kvm);
 
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 273490f..8aa3b95 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1612,7 +1612,8 @@  void kvm_vcpu_block(struct kvm_vcpu *vcpu)
 	for (;;) {
 		prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
 
-		if (kvm_cpu_has_interrupt(vcpu) ||
+		if ((kvm_arch_interrupt_allowed(vcpu) &&
+					kvm_cpu_has_interrupt(vcpu)) ||
 				kvm_arch_vcpu_runnable(vcpu)) {
 			set_bit(KVM_REQ_UNHALT, &vcpu->requests);
 			break;