diff options
author | Marcelo Tosatti <mtosatti@redhat.com> | 2008-07-27 00:01:01 +0400 |
---|---|---|
committer | Avi Kivity <avi@qumranet.com> | 2008-10-15 12:15:17 +0400 |
commit | 3cf57fed216e2c1b6fdfeccb792650bab72a350a (patch) | |
tree | 5a557f5870f5fccfbdee3bd61cab5a15e6cdc012 /arch/x86/kvm/i8254.h | |
parent | f52447261bc8c21dfd4635196e32d2da1352f589 (diff) | |
download | linux-3cf57fed216e2c1b6fdfeccb792650bab72a350a.tar.xz |
KVM: PIT: fix injection logic and count
The PIT injection logic is problematic under the following cases:
1) If there is a higher priority vector to be delivered by the time
kvm_pit_timer_intr_post is invoked ps->inject_pending won't be set.
This opens the possibility for missing many PIT event injections (say if
guest executes hlt at this point).
2) ps->inject_pending is racy with more than two vcpus. Since there's no locking
around read/dec of pt->pending, two vcpu's can inject two interrupts for a single
pt->pending count.
Fix 1 by using an irq ack notifier: only reinject when the previous irq
has been acked. Fix 2 with appropriate locking around manipulation of
pending count and irq_ack by the injection / ack paths.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'arch/x86/kvm/i8254.h')
-rw-r--r-- | arch/x86/kvm/i8254.h | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/arch/x86/kvm/i8254.h b/arch/x86/kvm/i8254.h index db25c2a6c8c4..e436d4983aa1 100644 --- a/arch/x86/kvm/i8254.h +++ b/arch/x86/kvm/i8254.h @@ -8,7 +8,6 @@ struct kvm_kpit_timer { int irq; s64 period; /* unit: ns */ s64 scheduled; - ktime_t last_update; atomic_t pending; }; @@ -34,8 +33,9 @@ struct kvm_kpit_state { u32 speaker_data_on; struct mutex lock; struct kvm_pit *pit; - bool inject_pending; /* if inject pending interrupts */ - unsigned long last_injected_time; + spinlock_t inject_lock; + unsigned long irq_ack; + struct kvm_irq_ack_notifier irq_ack_notifier; }; struct kvm_pit { @@ -54,7 +54,6 @@ struct kvm_pit { #define KVM_PIT_CHANNEL_MASK 0x3 void kvm_inject_pit_timer_irqs(struct kvm_vcpu *vcpu); -void kvm_pit_timer_intr_post(struct kvm_vcpu *vcpu, int vec); void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val); struct kvm_pit *kvm_create_pit(struct kvm *kvm); void kvm_free_pit(struct kvm *kvm); |