[PATCH 3/5] kvm: kick vcpu when async_pf is resolved

[Roman Kagan <rkagan@virtuozzo.com>]

When async_pf is ready the guest needs to be made aware of it ASAP,
because it may be holding off a higher priority task pending the
async_pf resolution in favor of a lower priority one.

In case async_pf's are harvested in vcpu context (x86) we have to not
only wake the vcpu up but kick it into host.

While at this, also replace the open-coded vcpu wakeup by the existing
helper.

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
---
 virt/kvm/async_pf.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c
index 9cced14..5f0a66c 100644
--- a/virt/kvm/async_pf.c
+++ b/virt/kvm/async_pf.c
@@ -105,8 +105,11 @@ static void async_pf_execute(struct work_struct *work)
 	 * This memory barrier pairs with prepare_to_wait's set_current_state()
 	 */
 	smp_mb();
-	if (swait_active(&vcpu->wq))
-		swake_up(&vcpu->wq);
+#ifdef CONFIG_KVM_ASYNC_PF_SYNC
+	kvm_vcpu_wake_up(vcpu);
+#else
+	kvm_vcpu_kick(vcpu);
+#endif
 
 	mmput(mm);
 	kvm_put_kvm(vcpu->kvm);
-- 
2.9.3