* [PATCH] If interrupt injection is not possible do not scan IRR.
@ 2009-05-18 8:44 Gleb Natapov
2009-05-18 9:00 ` Avi Kivity
2009-05-18 11:16 ` Gleb Natapov
0 siblings, 2 replies; 5+ messages in thread
From: Gleb Natapov @ 2009-05-18 8:44 UTC (permalink / raw)
To: avi; +Cc: kvm
Signed-off-by: Gleb Natapov <gleb@redhat.com>
---
arch/x86/kvm/i8259.c | 5 +++++
arch/x86/kvm/irq.c | 1 -
arch/x86/kvm/x86.c | 9 +++++----
3 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index 1ccb50c..d32ceac 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -218,6 +218,11 @@ int kvm_pic_read_irq(struct kvm *kvm)
struct kvm_pic *s = pic_irqchip(kvm);
pic_lock(s);
+ if (!s->output) {
+ pic_unlock(s);
+ return -1;
+ }
+ s->output = 0;
irq = pic_get_irq(&s->pics[0]);
if (irq >= 0) {
pic_intack(&s->pics[0], irq);
diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
index 96dfbb6..e93405a 100644
--- a/arch/x86/kvm/irq.c
+++ b/arch/x86/kvm/irq.c
@@ -78,7 +78,6 @@ int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
if (vector == -1) {
if (kvm_apic_accept_pic_intr(v)) {
s = pic_irqchip(v->kvm);
- s->output = 0; /* PIC */
vector = kvm_pic_read_irq(v->kvm);
}
}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 44e87a5..a08d96f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3174,10 +3174,11 @@ static void inject_pending_irq(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
vcpu->arch.nmi_injected = true;
kvm_x86_ops->set_nmi(vcpu);
}
- } else if (kvm_cpu_has_interrupt(vcpu)) {
- if (kvm_x86_ops->interrupt_allowed(vcpu)) {
- kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu),
- false);
+ } else if (kvm_x86_ops->interrupt_allowed(vcpu)) {
+ int vec = kvm_cpu_get_interrupt(vcpu);
+ if (vec != -1) {
+ printk(KERN_ERR"inject %d rip=%x\n", vec, kvm_rip_read(vcpu));
+ kvm_queue_interrupt(vcpu, vec, false);
kvm_x86_ops->set_irq(vcpu);
}
}
--
1.6.2.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] If interrupt injection is not possible do not scan IRR.
2009-05-18 8:44 [PATCH] If interrupt injection is not possible do not scan IRR Gleb Natapov
@ 2009-05-18 9:00 ` Avi Kivity
2009-05-18 9:08 ` Gleb Natapov
2009-05-18 11:16 ` Gleb Natapov
1 sibling, 1 reply; 5+ messages in thread
From: Avi Kivity @ 2009-05-18 9:00 UTC (permalink / raw)
To: Gleb Natapov; +Cc: kvm
Gleb Natapov wrote:
> @@ -3174,10 +3174,11 @@ static void inject_pending_irq(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
> vcpu->arch.nmi_injected = true;
> kvm_x86_ops->set_nmi(vcpu);
> }
> - } else if (kvm_cpu_has_interrupt(vcpu)) {
> - if (kvm_x86_ops->interrupt_allowed(vcpu)) {
> - kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu),
> - false);
> + } else if (kvm_x86_ops->interrupt_allowed(vcpu)) {
> + int vec = kvm_cpu_get_interrupt(vcpu);
> + if (vec != -1) {
> + printk(KERN_ERR"inject %d rip=%x\n", vec, kvm_rip_read(vcpu));
> + kvm_queue_interrupt(vcpu, vec, false);
> kvm_x86_ops->set_irq(vcpu);
> } }
>
Not sure if this is a win. Usually interrupts are allowed, so we'll
have to do both calculations. On vmx ->interrupt_allowed() reads the
vmcs, which is slow.
--
error compiling committee.c: too many arguments to function
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] If interrupt injection is not possible do not scan IRR.
2009-05-18 9:00 ` Avi Kivity
@ 2009-05-18 9:08 ` Gleb Natapov
0 siblings, 0 replies; 5+ messages in thread
From: Gleb Natapov @ 2009-05-18 9:08 UTC (permalink / raw)
To: Avi Kivity; +Cc: kvm
On Mon, May 18, 2009 at 12:00:40PM +0300, Avi Kivity wrote:
> Gleb Natapov wrote:
>> @@ -3174,10 +3174,11 @@ static void inject_pending_irq(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
>> vcpu->arch.nmi_injected = true;
>> kvm_x86_ops->set_nmi(vcpu);
>> }
>> - } else if (kvm_cpu_has_interrupt(vcpu)) {
>> - if (kvm_x86_ops->interrupt_allowed(vcpu)) {
>> - kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu),
>> - false);
>> + } else if (kvm_x86_ops->interrupt_allowed(vcpu)) {
>> + int vec = kvm_cpu_get_interrupt(vcpu);
>> + if (vec != -1) {
>> + printk(KERN_ERR"inject %d rip=%x\n", vec, kvm_rip_read(vcpu));
>> + kvm_queue_interrupt(vcpu, vec, false);
>> kvm_x86_ops->set_irq(vcpu);
>> } }
>>
>
> Not sure if this is a win. Usually interrupts are allowed, so we'll
> have to do both calculations. On vmx ->interrupt_allowed() reads the
> vmcs, which is slow.
>
Depend on how slow vmcs read is. In case when interrupt is available we
also scan IRR twice with current code: first time in kvm_cpu_has_interrupt()
and another in kvm_cpu_get_interrupt().
If we want to optimize vmcs access, and for nested virtualization we may
want to do it, we can read common ones on exit and use in memory copy.
--
Gleb.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] If interrupt injection is not possible do not scan IRR.
2009-05-18 8:44 [PATCH] If interrupt injection is not possible do not scan IRR Gleb Natapov
2009-05-18 9:00 ` Avi Kivity
@ 2009-05-18 11:16 ` Gleb Natapov
2009-05-19 9:50 ` Avi Kivity
1 sibling, 1 reply; 5+ messages in thread
From: Gleb Natapov @ 2009-05-18 11:16 UTC (permalink / raw)
To: avi; +Cc: kvm
Forget to remove debug output before submitting. Resending.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index 1ccb50c..d32ceac 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -218,6 +218,11 @@ int kvm_pic_read_irq(struct kvm *kvm)
struct kvm_pic *s = pic_irqchip(kvm);
pic_lock(s);
+ if (!s->output) {
+ pic_unlock(s);
+ return -1;
+ }
+ s->output = 0;
irq = pic_get_irq(&s->pics[0]);
if (irq >= 0) {
pic_intack(&s->pics[0], irq);
diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
index 96dfbb6..e93405a 100644
--- a/arch/x86/kvm/irq.c
+++ b/arch/x86/kvm/irq.c
@@ -78,7 +78,6 @@ int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
if (vector == -1) {
if (kvm_apic_accept_pic_intr(v)) {
s = pic_irqchip(v->kvm);
- s->output = 0; /* PIC */
vector = kvm_pic_read_irq(v->kvm);
}
}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 44e87a5..854e8c9 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3174,10 +3174,10 @@ static void inject_pending_irq(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
vcpu->arch.nmi_injected = true;
kvm_x86_ops->set_nmi(vcpu);
}
- } else if (kvm_cpu_has_interrupt(vcpu)) {
- if (kvm_x86_ops->interrupt_allowed(vcpu)) {
- kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu),
- false);
+ } else if (kvm_x86_ops->interrupt_allowed(vcpu)) {
+ int vec = kvm_cpu_get_interrupt(vcpu);
+ if (vec != -1) {
+ kvm_queue_interrupt(vcpu, vec, false);
kvm_x86_ops->set_irq(vcpu);
}
}
--
Gleb.
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] If interrupt injection is not possible do not scan IRR.
2009-05-18 11:16 ` Gleb Natapov
@ 2009-05-19 9:50 ` Avi Kivity
0 siblings, 0 replies; 5+ messages in thread
From: Avi Kivity @ 2009-05-19 9:50 UTC (permalink / raw)
To: Gleb Natapov; +Cc: kvm
Gleb Natapov wrote:
> Forget to remove debug output before submitting. Resending.
>
> Signed-off-by: Gleb Natapov <gleb@redhat.com>
> diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
> index 1ccb50c..d32ceac 100644
> --- a/arch/x86/kvm/i8259.c
> +++ b/arch/x86/kvm/i8259.c
> @@ -218,6 +218,11 @@ int kvm_pic_read_irq(struct kvm *kvm)
> struct kvm_pic *s = pic_irqchip(kvm);
>
> pic_lock(s);
> + if (!s->output) {
> + pic_unlock(s);
> + return -1;
> + }
> + s->output = 0;
> irq = pic_get_irq(&s->pics[0]);
> if (irq >= 0) {
> pic_intack(&s->pics[0], irq);
> diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
> index 96dfbb6..e93405a 100644
> --- a/arch/x86/kvm/irq.c
> +++ b/arch/x86/kvm/irq.c
> @@ -78,7 +78,6 @@ int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
> if (vector == -1) {
> if (kvm_apic_accept_pic_intr(v)) {
> s = pic_irqchip(v->kvm);
> - s->output = 0; /* PIC */
> vector = kvm_pic_read_irq(v->kvm);
> }
> }
>
Please split into a different patch. Even though it is a lot simpler,
it contains non-local changes and is therefore relatively dangerous.
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 44e87a5..854e8c9 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -3174,10 +3174,10 @@ static void inject_pending_irq(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
> vcpu->arch.nmi_injected = true;
> kvm_x86_ops->set_nmi(vcpu);
> }
> - } else if (kvm_cpu_has_interrupt(vcpu)) {
> - if (kvm_x86_ops->interrupt_allowed(vcpu)) {
> - kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu),
> - false);
> + } else if (kvm_x86_ops->interrupt_allowed(vcpu)) {
> + int vec = kvm_cpu_get_interrupt(vcpu);
> + if (vec != -1) {
> + kvm_queue_interrupt(vcpu, vec, false);
> kvm_x86_ops->set_irq(vcpu);
> }
> }
>
Again, I don't think this is a win. Usually ->interrupts_allowed() ==
true so we'll execute the rest anyway.
Perhaps we could move the call to has_interrupt into get_interrupt.
--
error compiling committee.c: too many arguments to function
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2009-05-19 9:50 UTC | newest]
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2009-05-18 8:44 [PATCH] If interrupt injection is not possible do not scan IRR Gleb Natapov
2009-05-18 9:00 ` Avi Kivity
2009-05-18 9:08 ` Gleb Natapov
2009-05-18 11:16 ` Gleb Natapov
2009-05-19 9:50 ` Avi Kivity
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