Re: [Xen-devel] [PATCH v4 6/6] xen/arm: disable a physical IRQ when the guest disables the corresponding IRQ

[Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>]

On Thu, 12 Dec 2013, Ian Campbell wrote:
> On Wed, 2013-12-11 at 19:07 +0000, Stefano Stabellini wrote:
> > Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
> > Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
> > Acked-by: Julien Grall <julien.grall@xxxxxxxxxx>
> > 
> > ---
> > Changes in v2:
> > - disable IRQs that were previously disabled.
> > ---
> >  xen/arch/arm/vgic.c |   18 ++++++++++++++++++
> >  1 file changed, 18 insertions(+)
> > 
> > diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
> > index ad17d1d..9022658 100644
> > --- a/xen/arch/arm/vgic.c
> > +++ b/xen/arch/arm/vgic.c
> > @@ -360,6 +360,22 @@ read_as_zero:
> >      return 1;
> >  }
> >  
> > +static void vgic_disable_irqs(struct vcpu *v, uint32_t r, int n)
> > +{
> > +    struct pending_irq *p;
> > +    unsigned int irq;
> > +    int i = 0;
> > +
> > +    while ( (i = find_next_bit((const long unsigned int *) &r, 32, i)) < 
> > 32 ) {
> > +        irq = i + (32 * n);
> > +        p = irq_to_pending(v, irq);
> > +        clear_bit(GIC_IRQ_GUEST_ENABLED, &p->status);
> 
> Do we need to remove from some queues, like lr_pending? In case it is
> already pending when it gets masked we don't want to pick it off the
> queue in the maint interrupt do we?

I think that you are right. Removing irqs from lr_pending should be all
that is needed to solve this problem.

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