On 15.08.2012, at 02:10, Scott Wood wrote:
> On 08/14/2012 06:04 PM, Alexander Graf wrote:
>> We need a central place to check for pending requests in. Add one that
>> only does the timer check we already do in a different place.
>>
>> Later, this central function can be extended by more checks.
>>
>> Signed-off-by: Alexander Graf <agraf@xxxxxxx>
>> ---
>> arch/powerpc/kvm/booke.c | 24 +++++++++++++++++-------
>> 1 files changed, 17 insertions(+), 7 deletions(-)
>>
>> diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
>> index 1d4ce9a..bcf87fe 100644
>> --- a/arch/powerpc/kvm/booke.c
>> +++ b/arch/powerpc/kvm/booke.c
>> @@ -419,13 +419,6 @@ static void kvmppc_core_check_exceptions(struct kvm_vcpu *vcpu)
>> unsigned long *pending = &vcpu->arch.pending_exceptions;
>> unsigned int priority;
>>
>> - if (vcpu->requests) {
>> - if (kvm_check_request(KVM_REQ_PENDING_TIMER, vcpu)) {
>> - smp_mb();
>> - update_timer_ints(vcpu);
>> - }
>> - }
>> -
>> priority = __ffs(*pending);
>> while (priority < BOOKE_IRQPRIO_MAX) {
>> if (kvmppc_booke_irqprio_deliver(vcpu, priority))
>> @@ -461,6 +454,14 @@ int kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu)
>> return r;
>> }
>>
>> +static void kvmppc_check_requests(struct kvm_vcpu *vcpu)
>> +{
>> + if (vcpu->requests) {
>> + if (kvm_check_request(KVM_REQ_PENDING_TIMER, vcpu))
>> + update_timer_ints(vcpu);
>> + }
>> +}
>> +
>> /*
>> * Common checks before entering the guest world. Call with interrupts
>> * disabled.
>> @@ -485,6 +486,15 @@ static int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu)
>> break;
>> }
>>
>> + smp_mb();
>> + if (vcpu->requests) {
>> + /* Make sure we process requests preemptable */
>> + local_irq_enable();
>> + kvmppc_check_requests(vcpu);
>> + local_irq_disable();
>> + continue;
>> + }
>
> What previous memory access is the smp_mb() ordering against?
Against itself really (see the continue?). I might have just gotten this wrong though :).
Alex
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