On 27.02.2012, at 20:28, Scott Wood wrote:
> On 02/24/2012 08:26 AM, Alexander Graf wrote:
>> -void kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu)
>> +int kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu)
>> {
>> unsigned long *pending = &vcpu->arch.pending_exceptions;
>> unsigned long old_pending = vcpu->arch.pending_exceptions;
>> @@ -283,6 +283,8 @@ void kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu)
>>
>> /* Tell the guest about our interrupt status */
>> kvmppc_update_int_pending(vcpu, *pending, old_pending);
>> +
>> + return 0;
>> }
>>
>> pfn_t kvmppc_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn)
>> diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
>> index 9979be1..3fcec2c 100644
>> --- a/arch/powerpc/kvm/booke.c
>> +++ b/arch/powerpc/kvm/booke.c
>> @@ -439,8 +439,9 @@ static void kvmppc_core_check_exceptions(struct kvm_vcpu
>> *vcpu)
>> }
>>
>> /* Check pending exceptions and deliver one, if possible. */
>> -void kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu)
>> +int kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu)
>> {
>> + int r = 0;
>> WARN_ON_ONCE(!irqs_disabled());
>>
>> kvmppc_core_check_exceptions(vcpu);
>> @@ -451,8 +452,44 @@ void kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu)
>> local_irq_disable();
>>
>> kvmppc_set_exit_type(vcpu, EMULATED_MTMSRWE_EXITS);
>> - kvmppc_core_check_exceptions(vcpu);
>> + r = 1;
>> };
>> +
>> + return r;
>> +}
>> +
>> +/*
>> + * Common checks before entering the guest world. Call with interrupts
>> + * disabled.
>> + *
>> + * returns !0 if a signal is pending and check_signal is true
>> + */
>> +static int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu, bool check_signal)
>> +{
>> + int r = 0;
>> +
>> + WARN_ON_ONCE(!irqs_disabled());
>> + while (true) {
>> + if (need_resched()) {
>> + local_irq_enable();
>> + cond_resched();
>> + local_irq_disable();
>> + continue;
>> + }
>> +
>> + if (kvmppc_core_prepare_to_enter(vcpu)) {
>> + /* interrupts got enabled in between, so we
>> + are back at square 1 */
>> + continue;
>> + }
>> +
>> +
>> + if (check_signal && signal_pending(current))
>> + r = 1;
>
> If there is a signal pending and MSR[WE] is set, we'll loop forever
> without reaching this check.
Good point. How about something like this on top (will fold in later)?
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 430055e..9f27258 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -477,15 +477,17 @@ static int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu)
continue;
}
+ if (signal_pending(current)) {
+ r = 1;
+ break;
+ }
+
if (kvmppc_core_prepare_to_enter(vcpu)) {
/* interrupts got enabled in between, so we
are back at square 1 */
continue;
}
- if (signal_pending(current))
- r = 1;
-
break;
}
Alex
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