Re: [PATCH] KVM: PPC: booke: check for signals in kvmppc_vcpu_run

Scott Wood
2011-11-11T15:32:06Z

On Fri, Nov 11, 2011 at 03:09:17PM +0100, Alexander Graf wrote:
> On 11/08/2011 11:11 PM, Scott Wood wrote:
> >Currently we check prior to returning from a lightweight exit,
> >but not prior to initial entry.
> >
> >book3s already does a similar test.
> >
> >Signed-off-by: Scott Wood<scottwood@freescale.com>
> >---
> > arch/powerpc/kvm/booke.c | 10 +++++++++-
> > 1 files changed, 9 insertions(+), 1 deletions(-)
> >
> >diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
> >index b642200..9c78589 100644
> >--- a/arch/powerpc/kvm/booke.c
> >+++ b/arch/powerpc/kvm/booke.c
> >@@ -322,11 +322,19 @@ int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
> > }
> >
> > local_irq_disable();
> >+
> >+ if (signal_pending(current)) {
>
> Any reason you're doing this after irq_disable()?

If we get a signal after the check, we want to be sure that we don't
receive the reschedule IPI until after we're in the guest, so that it
will cause another signal check.

-Scott