On 11/01/2010 08:55 PM, Gleb Natapov wrote:

quoted text
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 2cfdf2d..f7aed95 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -5295,8 +5295,9 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
>  			{
>  				switch(vcpu->arch.mp_state) {
>  				case KVM_MP_STATE_HALTED:
> -					vcpu->arch.mp_state =
> -						KVM_MP_STATE_RUNNABLE;
> +					if (list_empty_careful(&vcpu->async_pf.done))
> +						vcpu->arch.mp_state =
> +							KVM_MP_STATE_RUNNABLE;

if nmi/interrupt and apfs completed event occur at the same time, we will miss to
exit halt sate. Maybe we can check the pending event here, see below patch please.

quoted text
>  				case KVM_MP_STATE_RUNNABLE:
>  					vcpu->arch.apf.halted = false;
>  					break;
> @@ -6279,6 +6280,7 @@ void kvm_arch_async_page_present(struct kvm_vcpu *vcpu,
>  		vcpu->arch.fault.error_code = 0;
>  		vcpu->arch.fault.address = work->arch.token;
>  		kvm_inject_page_fault(vcpu);
> +		vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
>  	}
>  }

Have a stupid question, why we make the vcpu runnable here? Sorry i don't know
kvm pv guest to much. :-(

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2044302..27a712b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5267,6 +5267,12 @@ out:
 	return r;
 }
 
+static bool kvm_vcpu_leave_halt_state(struct kvm_vcpu *vcpu)
+{
+	return vcpu->arch.nmi_pending ||
+		(kvm_arch_interrupt_allowed(vcpu) &&
+		 kvm_cpu_has_interrupt(vcpu));
+}
 
 static int __vcpu_run(struct kvm_vcpu *vcpu)
 {
@@ -5299,8 +5305,9 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
 			{
 				switch(vcpu->arch.mp_state) {
 				case KVM_MP_STATE_HALTED:
-					vcpu->arch.mp_state =
-						KVM_MP_STATE_RUNNABLE;
+					if (kvm_vcpu_leave_halt_state(vcpu))
+						vcpu->arch.mp_state =
+							KVM_MP_STATE_RUNNABLE;
 				case KVM_MP_STATE_RUNNABLE:
 					vcpu->arch.apf.halted = false;
 					break;
@@ -6113,9 +6120,7 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
 		!vcpu->arch.apf.halted)
 		|| !list_empty_careful(&vcpu->async_pf.done)
 		|| vcpu->arch.mp_state == KVM_MP_STATE_SIPI_RECEIVED
-		|| vcpu->arch.nmi_pending ||
-		(kvm_arch_interrupt_allowed(vcpu) &&
-		 kvm_cpu_has_interrupt(vcpu));
+		|| kvm_vcpu_leave_halt_state(vcpu);
 }
 
 void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
--
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