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KVM: deliver PIC interrupt only to vcpu0

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This patch changes the PIC interrupts delivery. Now it is only delivered
to vcpu0 when either condition is met (on vcpu0):
  1. local APIC is hardware disabled
  2. LVT0 is unmasked and configured to delivery mode ExtInt

It fixes the 2x faster wall clock on x86_64 and SMP i386 Linux guests

Signed-off-by: Eddie (Yaozu) Dong <eddie.dong@intel.com>
Signed-off-by: Qing He <qing.he@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
This commit is contained in:
Qing He
2007-09-17 14:47:13 +08:00
committed by Avi Kivity
parent 5cd4f6fd85
commit 40487c680d
3 changed files with 28 additions and 5 deletions
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15
drivers/kvm/irq.c
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@ -33,8 +33,11 @@ int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
struct kvm_pic *s;
if (kvm_apic_has_interrupt(v) == -1) { /* LAPIC */
s = pic_irqchip(v->kvm); /* PIC */
return s->output;
if (kvm_apic_accept_pic_intr(v)) {
s = pic_irqchip(v->kvm); /* PIC */
return s->output;
} else
return 0;
}
return 1;
}
@ -50,9 +53,11 @@ int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
vector = kvm_get_apic_interrupt(v); /* APIC */
if (vector == -1) {
s = pic_irqchip(v->kvm);
s->output = 0; /* PIC */
vector = kvm_pic_read_irq(s);
if (kvm_apic_accept_pic_intr(v)) {
s = pic_irqchip(v->kvm);
s->output = 0; /* PIC */
vector = kvm_pic_read_irq(s);
}
}
return vector;
}