KVM: x86: do not execute halted vcpus

Offline or uninitialized vcpu's can be executed if requested to perform
userspace work.

Follow Avi's suggestion to handle halted vcpu's in the main loop,
simplifying kvm_emulate_halt(). Introduce a new vcpu->requests bit to
indicate events that promote state from halted to running.

Also standardize vcpu wake sites.

Signed-off-by: Marcelo Tosatti <mtosatti <at> redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 2 insertions, 3 deletions

diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index 4cb443026ec4..634132a9a512 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -200,10 +200,9 @@ static int __pit_timer_fn(struct kvm_kpit_state *ps)
 
         if (!atomic_inc_and_test(&pt->pending))
                 set_bit(KVM_REQ_PENDING_TIMER, &vcpu0->requests);
-        if (vcpu0 && waitqueue_active(&vcpu0->wq)) {
-                vcpu0->arch.mp_state = KVM_MP_STATE_RUNNABLE;
+
+        if (vcpu0 && waitqueue_active(&vcpu0->wq))
                 wake_up_interruptible(&vcpu0->wq);
-        }
 
         pt->timer.expires = ktime_add_ns(pt->timer.expires, pt->period);
         pt->scheduled = ktime_to_ns(pt->timer.expires);