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authorMarcelo Tosatti <mtosatti@redhat.com>2008-04-11 14:53:26 -0300
committerAvi Kivity <avi@qumranet.com>2008-04-27 12:04:11 +0300
commit3d80840d96127401ba6aeadd813c3a15b84e70fe (patch)
treeb3e083c651f09fee362d88f0d1fc140194f2431d /arch/x86/kvm/irq.c
parent3564990af1b9f77a63692c1079e9c41af229f066 (diff)
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/x86/kvm/irq.c')
-rw-r--r--arch/x86/kvm/irq.c15
1 files changed, 15 insertions, 0 deletions
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.
*/