On Tue, Aug 14, 2012 at 07:10:43PM -0500, 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 <[email protected]> > > --- > > 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? > > -Scott
It is good practice to document each memory barrier. -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
