KVM: x86: Introduce a workqueue to deliver PIT timer interrupts

We really want to "kvm_set_irq" during the hrtimer callback,
but that is risky because that is during interrupt context.
Instead, offload the work to a workqueue, which is a bit safer
and should provide most of the same functionality.

Signed-off-by: Chris Lalancette <clalance@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/arch/x86/kvm/i8254.h b/arch/x86/kvm/i8254.h
index 900d6b0ba7c2..46d08ca0b48f 100644
--- a/arch/x86/kvm/i8254.h
+++ b/arch/x86/kvm/i8254.h
@@ -27,7 +27,7 @@ struct kvm_kpit_state {
         u32    speaker_data_on;
         struct mutex lock;
         struct kvm_pit *pit;
-        raw_spinlock_t inject_lock;
+        spinlock_t inject_lock;
         unsigned long irq_ack;
         struct kvm_irq_ack_notifier irq_ack_notifier;
 };
@@ -40,6 +40,8 @@ struct kvm_pit {
         struct kvm_kpit_state pit_state;
         int irq_source_id;
         struct kvm_irq_mask_notifier mask_notifier;
+        struct workqueue_struct *wq;
+        struct work_struct expired;
 };
 
 #define KVM_PIT_BASE_ADDRESS        0x40