* [PATCH] KVM: remove isr_ack logic from PIC
@ 2011-02-09 10:09 Gleb Natapov
2011-02-10 10:37 ` Avi Kivity
0 siblings, 1 reply; 2+ messages in thread
From: Gleb Natapov @ 2011-02-09 10:09 UTC (permalink / raw)
To: avi, mtosatti; +Cc: kvm
isr_ack logic was added by e48258009d to avoid unnecessary IPIs. Back
then it made sense, but now the code checks that vcpu is ready to accept
interrupt before sending IPI, so this logic is no longer needed. The
patch removes it.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index 3cece05..5528484 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -62,9 +62,6 @@ static void pic_unlock(struct kvm_pic *s)
}
if (!found)
- found = s->kvm->bsp_vcpu;
-
- if (!found)
return;
kvm_make_request(KVM_REQ_EVENT, found);
@@ -75,7 +72,6 @@ static void pic_unlock(struct kvm_pic *s)
static void pic_clear_isr(struct kvm_kpic_state *s, int irq)
{
s->isr &= ~(1 << irq);
- s->isr_ack |= (1 << irq);
if (s != &s->pics_state->pics[0])
irq += 8;
/*
@@ -89,16 +85,6 @@ static void pic_clear_isr(struct kvm_kpic_state *s, int irq)
pic_lock(s->pics_state);
}
-void kvm_pic_clear_isr_ack(struct kvm *kvm)
-{
- struct kvm_pic *s = pic_irqchip(kvm);
-
- pic_lock(s);
- s->pics[0].isr_ack = 0xff;
- s->pics[1].isr_ack = 0xff;
- pic_unlock(s);
-}
-
/*
* set irq level. If an edge is detected, then the IRR is set to 1
*/
@@ -281,7 +267,6 @@ void kvm_pic_reset(struct kvm_kpic_state *s)
s->irr = 0;
s->imr = 0;
s->isr = 0;
- s->isr_ack = 0xff;
s->priority_add = 0;
s->irq_base = 0;
s->read_reg_select = 0;
@@ -545,15 +530,11 @@ static int picdev_read(struct kvm_io_device *this,
*/
static void pic_irq_request(struct kvm *kvm, int level)
{
- struct kvm_vcpu *vcpu = kvm->bsp_vcpu;
struct kvm_pic *s = pic_irqchip(kvm);
- int irq = pic_get_irq(&s->pics[0]);
- s->output = level;
- if (vcpu && level && (s->pics[0].isr_ack & (1 << irq))) {
- s->pics[0].isr_ack &= ~(1 << irq);
+ if (!s->output)
s->wakeup_needed = true;
- }
+ s->output = level;
}
static const struct kvm_io_device_ops picdev_ops = {
@@ -575,8 +556,6 @@ struct kvm_pic *kvm_create_pic(struct kvm *kvm)
s->pics[1].elcr_mask = 0xde;
s->pics[0].pics_state = s;
s->pics[1].pics_state = s;
- s->pics[0].isr_ack = 0xff;
- s->pics[1].isr_ack = 0xff;
/*
* Initialize PIO device
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 8575d85..dffff0e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2669,8 +2669,6 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu,
vcpu->arch.interrupt.pending = events->interrupt.injected;
vcpu->arch.interrupt.nr = events->interrupt.nr;
vcpu->arch.interrupt.soft = events->interrupt.soft;
- if (vcpu->arch.interrupt.pending && irqchip_in_kernel(vcpu->kvm))
- kvm_pic_clear_isr_ack(vcpu->kvm);
if (events->flags & KVM_VCPUEVENT_VALID_SHADOW)
kvm_x86_ops->set_interrupt_shadow(vcpu,
events->interrupt.shadow);
@@ -5619,8 +5617,6 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
if (pending_vec < max_bits) {
kvm_queue_interrupt(vcpu, pending_vec, false);
pr_debug("Set back pending irq %d\n", pending_vec);
- if (irqchip_in_kernel(vcpu->kvm))
- kvm_pic_clear_isr_ack(vcpu->kvm);
}
kvm_set_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
--
Gleb.
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] KVM: remove isr_ack logic from PIC
2011-02-09 10:09 [PATCH] KVM: remove isr_ack logic from PIC Gleb Natapov
@ 2011-02-10 10:37 ` Avi Kivity
0 siblings, 0 replies; 2+ messages in thread
From: Avi Kivity @ 2011-02-10 10:37 UTC (permalink / raw)
To: Gleb Natapov; +Cc: mtosatti, kvm
On 02/09/2011 12:09 PM, Gleb Natapov wrote:
> isr_ack logic was added by e48258009d to avoid unnecessary IPIs. Back
> then it made sense, but now the code checks that vcpu is ready to accept
> interrupt before sending IPI, so this logic is no longer needed. The
> patch removes it.
>
Applied, thanks.
--
error compiling committee.c: too many arguments to function
^ permalink raw reply [flat|nested] 2+ messages in thread
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