diff options
author | Marcelo Tosatti <mtosatti@redhat.com> | 2008-04-11 14:53:26 -0300 |
---|---|---|
committer | Avi Kivity <avi@qumranet.com> | 2008-04-27 12:04:11 +0300 |
commit | 3d80840d96127401ba6aeadd813c3a15b84e70fe (patch) | |
tree | b3e083c651f09fee362d88f0d1fc140194f2431d /arch | |
parent | 3564990af1b9f77a63692c1079e9c41af229f066 (diff) | |
download | linux-3d80840d96127401ba6aeadd813c3a15b84e70fe.tar.bz2 |
KVM: hlt emulation should take in-kernel APIC/PIT timers into account
Timers that fire between guest hlt and vcpu_block's add_wait_queue() are
ignored, possibly resulting in hangs.
Also make sure that atomic_inc and waitqueue_active tests happen in the
specified order, otherwise the following race is open:
CPU0 CPU1
if (waitqueue_active(wq))
add_wait_queue()
if (!atomic_read(pit_timer->pending))
schedule()
atomic_inc(pit_timer->pending)
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/ia64/kvm/kvm-ia64.c | 5 | ||||
-rw-r--r-- | arch/s390/kvm/interrupt.c | 5 | ||||
-rw-r--r-- | arch/x86/kvm/i8254.c | 10 | ||||
-rw-r--r-- | arch/x86/kvm/irq.c | 15 | ||||
-rw-r--r-- | arch/x86/kvm/irq.h | 3 | ||||
-rw-r--r-- | arch/x86/kvm/lapic.c | 10 |
6 files changed, 48 insertions, 0 deletions
diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c index 9c56b6429cb6..ca1cfb124d4f 100644 --- a/arch/ia64/kvm/kvm-ia64.c +++ b/arch/ia64/kvm/kvm-ia64.c @@ -1778,6 +1778,11 @@ int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu) return 0; } +int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu) +{ + return 0; +} + gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn) { return gfn; diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index f62588cb75f8..fcd1ed8015c1 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -325,6 +325,11 @@ int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu) return rc; } +int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu) +{ + return 0; +} + int kvm_s390_handle_wait(struct kvm_vcpu *vcpu) { u64 now, sltime; diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index 9f118e2f350d..ed1af80432b3 100644 --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -212,6 +212,16 @@ int __pit_timer_fn(struct kvm_kpit_state *ps) return (pt->period == 0 ? 0 : 1); } +int pit_has_pending_timer(struct kvm_vcpu *vcpu) +{ + struct kvm_pit *pit = vcpu->kvm->arch.vpit; + + if (pit && vcpu->vcpu_id == 0) + return atomic_read(&pit->pit_state.pit_timer.pending); + + return 0; +} + static enum hrtimer_restart pit_timer_fn(struct hrtimer *data) { struct kvm_kpit_state *ps; diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c index dbfe21c99c48..ce1f583459b1 100644 --- a/arch/x86/kvm/irq.c +++ b/arch/x86/kvm/irq.c @@ -26,6 +26,21 @@ #include "i8254.h" /* + * check if there are pending timer events + * to be processed. + */ +int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu) +{ + int ret; + + ret = pit_has_pending_timer(vcpu); + ret |= apic_has_pending_timer(vcpu); + + return ret; +} +EXPORT_SYMBOL(kvm_cpu_has_pending_timer); + +/* * check if there is pending interrupt without * intack. */ diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h index fa5ed5d59b5d..1802134b836f 100644 --- a/arch/x86/kvm/irq.h +++ b/arch/x86/kvm/irq.h @@ -85,4 +85,7 @@ void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu); void kvm_inject_apic_timer_irqs(struct kvm_vcpu *vcpu); void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu); +int pit_has_pending_timer(struct kvm_vcpu *vcpu); +int apic_has_pending_timer(struct kvm_vcpu *vcpu); + #endif diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 31280df7d2e3..debf58211bdd 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -952,6 +952,16 @@ static int __apic_timer_fn(struct kvm_lapic *apic) return result; } +int apic_has_pending_timer(struct kvm_vcpu *vcpu) +{ + struct kvm_lapic *lapic = vcpu->arch.apic; + + if (lapic) + return atomic_read(&lapic->timer.pending); + + return 0; +} + static int __inject_apic_timer_irq(struct kvm_lapic *apic) { int vector; |