diff options
| author | Qing He <qing.he@intel.com> | 2007-09-17 14:47:13 +0800 |
|---|---|---|
| committer | Avi Kivity <avi@qumranet.com> | 2007-10-13 10:18:26 +0200 |
| commit | 40487c680d5855459dfdce340df13d40071bb774 (patch) | |
| tree | abc0ec56ecb1b6d1533b918621c060a1d38fccef /drivers/kvm | |
| parent | 5cd4f6fd8506f59cb8a232f364c54f6bd8e5150a (diff) | |
| download | linux-40487c680d5855459dfdce340df13d40071bb774.tar.bz2 | |
KVM: deliver PIC interrupt only to vcpu0
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>
Diffstat (limited to 'drivers/kvm')
| -rw-r--r-- | drivers/kvm/irq.c | 15 | ||||
| -rw-r--r-- | drivers/kvm/irq.h | 1 | ||||
| -rw-r--r-- | drivers/kvm/lapic.c | 17 |
3 files changed, 28 insertions, 5 deletions
diff --git a/drivers/kvm/irq.c b/drivers/kvm/irq.c index b88e50115588..7628c7ff628f 100644 --- a/drivers/kvm/irq.c +++ b/drivers/kvm/irq.c @@ -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; } diff --git a/drivers/kvm/irq.h b/drivers/kvm/irq.h index f324cfb40084..ec46a09e2135 100644 --- a/drivers/kvm/irq.h +++ b/drivers/kvm/irq.h @@ -135,6 +135,7 @@ do { \ void kvm_vcpu_kick(struct kvm_vcpu *vcpu); int kvm_apic_has_interrupt(struct kvm_vcpu *vcpu); +int kvm_apic_accept_pic_intr(struct kvm_vcpu *vcpu); int kvm_get_apic_interrupt(struct kvm_vcpu *vcpu); int kvm_create_lapic(struct kvm_vcpu *vcpu); void kvm_free_apic(struct kvm_lapic *apic); diff --git a/drivers/kvm/lapic.c b/drivers/kvm/lapic.c index 2706ec36c258..01e769672dcc 100644 --- a/drivers/kvm/lapic.c +++ b/drivers/kvm/lapic.c @@ -788,6 +788,8 @@ static void lapic_reset(struct kvm_vcpu *vcpu) for (i = 0; i < APIC_LVT_NUM; i++) apic_set_reg(apic, APIC_LVTT + 0x10 * i, APIC_LVT_MASKED); + apic_set_reg(apic, APIC_LVT0, + SET_APIC_DELIVERY_MODE(0, APIC_MODE_EXTINT)); apic_set_reg(apic, APIC_DFR, 0xffffffffU); apic_set_reg(apic, APIC_SPIV, 0xff); @@ -932,6 +934,21 @@ int kvm_apic_has_interrupt(struct kvm_vcpu *vcpu) return highest_irr; } +int kvm_apic_accept_pic_intr(struct kvm_vcpu *vcpu) +{ + u32 lvt0 = apic_get_reg(vcpu->apic, APIC_LVT0); + int r = 0; + + if (vcpu->vcpu_id == 0) { + if (!apic_hw_enabled(vcpu->apic)) + r = 1; + if ((lvt0 & APIC_LVT_MASKED) == 0 && + GET_APIC_DELIVERY_MODE(lvt0) == APIC_MODE_EXTINT) + r = 1; + } + return r; +} + void kvm_inject_apic_timer_irqs(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->apic; |