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, 4 insertions, 12 deletions

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index be94f93a73f6..fd00f698692f 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -339,13 +339,7 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
                 } else
                         apic_clear_vector(vector, apic->regs + APIC_TMR);
 
-                if (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE)
-                        kvm_vcpu_kick(vcpu);
-                else if (vcpu->arch.mp_state == KVM_MP_STATE_HALTED) {
-                        vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
-                        if (waitqueue_active(&vcpu->wq))
-                                wake_up_interruptible(&vcpu->wq);
-                }
+                kvm_vcpu_kick(vcpu);
 
                 result = (orig_irr == 0);
                 break;
@@ -384,8 +378,7 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
                 if (vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED) {
                         vcpu->arch.sipi_vector = vector;
                         vcpu->arch.mp_state = KVM_MP_STATE_SIPI_RECEIVED;
-                        if (waitqueue_active(&vcpu->wq))
-                                wake_up_interruptible(&vcpu->wq);
+                        kvm_vcpu_kick(vcpu);
                 }
                 break;
 
@@ -950,10 +943,9 @@ static int __apic_timer_fn(struct kvm_lapic *apic)
 
         if(!atomic_inc_and_test(&apic->timer.pending))
                 set_bit(KVM_REQ_PENDING_TIMER, &apic->vcpu->requests);
-        if (waitqueue_active(q)) {
-                apic->vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
+        if (waitqueue_active(q))
                 wake_up_interruptible(q);
-        }
+
         if (apic_lvtt_period(apic)) {
                 result = 1;
                 apic->timer.dev.expires = ktime_add_ns(