KVM: Timer event should not unconditionally unhalt vcpu.

Currently timer events are processed before entering guest mode. Move it
to main vcpu event loop since timer events should be processed even while
vcpu is halted.  Timer may cause interrupt/nmi to be injected and only then
vcpu will be unhalted.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 34 insertions, 23 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c0ae5e6cba9..8fca7a4e95a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3133,9 +3133,6 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
                 }
         }
 
-        clear_bit(KVM_REQ_PENDING_TIMER, &vcpu->requests);
-        kvm_inject_pending_timer_irqs(vcpu);
-
         preempt_disable();
 
         kvm_x86_ops->prepare_guest_switch(vcpu);
@@ -3235,6 +3232,7 @@ out:
         return r;
 }
 
+
 static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 {
         int r;
@@ -3261,29 +3259,42 @@ static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
                         kvm_vcpu_block(vcpu);
                         down_read(&vcpu->kvm->slots_lock);
                         if (test_and_clear_bit(KVM_REQ_UNHALT, &vcpu->requests))
-                                if (vcpu->arch.mp_state == KVM_MP_STATE_HALTED)
+                        {
+                                switch(vcpu->arch.mp_state) {
+                                case KVM_MP_STATE_HALTED:
                                         vcpu->arch.mp_state =
-                                                        KVM_MP_STATE_RUNNABLE;
-                        if (vcpu->arch.mp_state != KVM_MP_STATE_RUNNABLE)
-                                r = -EINTR;
+                                                KVM_MP_STATE_RUNNABLE;
+                                case KVM_MP_STATE_RUNNABLE:
+                                        break;
+                                case KVM_MP_STATE_SIPI_RECEIVED:
+                                default:
+                                        r = -EINTR;
+                                        break;
+                                }
+                        }
                 }
 
-                if (r > 0) {
-                        if (dm_request_for_irq_injection(vcpu, kvm_run)) {
-                                r = -EINTR;
-                                kvm_run->exit_reason = KVM_EXIT_INTR;
-                                ++vcpu->stat.request_irq_exits;
-                        }
-                        if (signal_pending(current)) {
-                                r = -EINTR;
-                                kvm_run->exit_reason = KVM_EXIT_INTR;
-                                ++vcpu->stat.signal_exits;
-                        }
-                        if (need_resched()) {
-                                up_read(&vcpu->kvm->slots_lock);
-                                kvm_resched(vcpu);
-                                down_read(&vcpu->kvm->slots_lock);
-                        }
+                if (r <= 0)
+                        break;
+
+                clear_bit(KVM_REQ_PENDING_TIMER, &vcpu->requests);
+                if (kvm_cpu_has_pending_timer(vcpu))
+                        kvm_inject_pending_timer_irqs(vcpu);
+
+                if (dm_request_for_irq_injection(vcpu, kvm_run)) {
+                        r = -EINTR;
+                        kvm_run->exit_reason = KVM_EXIT_INTR;
+                        ++vcpu->stat.request_irq_exits;
+                }
+                if (signal_pending(current)) {
+                        r = -EINTR;
+                        kvm_run->exit_reason = KVM_EXIT_INTR;
+                        ++vcpu->stat.signal_exits;
+                }
+                if (need_resched()) {
+                        up_read(&vcpu->kvm->slots_lock);
+                        kvm_resched(vcpu);
+                        down_read(&vcpu->kvm->slots_lock);
                 }
         }