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>
git-mirror · Jun 10, 2009 · 09cec75 · 09cec75
1 parent 089d034
commit 09cec75
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Showing 3 changed files with 40 additions and 28 deletions.
diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
@@ -488,10 +488,10 @@ int kvm_emulate_halt(struct kvm_vcpu *vcpu)
 		hrtimer_cancel(p_ht);
 		vcpu->arch.ht_active = 0;
 
-		if (test_and_clear_bit(KVM_REQ_UNHALT, &vcpu->requests))
+		if (test_and_clear_bit(KVM_REQ_UNHALT, &vcpu->requests) ||
+				kvm_cpu_has_pending_timer(vcpu))
 			if (vcpu->arch.mp_state == KVM_MP_STATE_HALTED)
-				vcpu->arch.mp_state =
-					KVM_MP_STATE_RUNNABLE;
+				vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
 
 		if (vcpu->arch.mp_state != KVM_MP_STATE_RUNNABLE)
 			return -EINTR;

diff --git 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 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 	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);
 		}
 	}
 

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
@@ -1611,11 +1611,12 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
 		prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
 
 		if (kvm_cpu_has_interrupt(vcpu) ||
-		    kvm_cpu_has_pending_timer(vcpu) ||
-		    kvm_arch_vcpu_runnable(vcpu)) {
+				kvm_arch_vcpu_runnable(vcpu)) {
 			set_bit(KVM_REQ_UNHALT, &vcpu->requests);
 			break;
 		}
+		if (kvm_cpu_has_pending_timer(vcpu))
+			break;
 		if (signal_pending(current))
 			break;