Re: [PATCH] KVM: arm64: vgic-debug: Don't put unmarked LPIs

Zenghui Yu
2024-08-17T10:31:49Z

On 2024/8/17 18:25, Marc Zyngier wrote:
> On Sat, 17 Aug 2024 11:15:41 +0100,
> Zenghui Yu <yuzenghui@huawei.com> wrote:
> >
> > If there were LPIs being mapped behind our back (i.e., between .start() and
> > .stop()), we would put them at iter_unmark_lpis() without checking if they
> > were actually *marked*, which is obviously not good.
> >
> > Switch to use the xa_for_each_marked() iterator to fix it.
> >
> > Fixes: 85d3ccc8b75b ("KVM: arm64: vgic-debug: Use an xarray mark for debug iterator")
> > Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
> > ---
> > arch/arm64/kvm/vgic/vgic-debug.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/arm64/kvm/vgic/vgic-debug.c b/arch/arm64/kvm/vgic/vgic-debug.c
> > index bc74d06398ef..e1397ab2072a 100644
> > --- a/arch/arm64/kvm/vgic/vgic-debug.c
> > +++ b/arch/arm64/kvm/vgic/vgic-debug.c
> > @@ -85,7 +85,7 @@ static void iter_unmark_lpis(struct kvm *kvm)
> > struct vgic_irq *irq;
> > unsigned long intid;
> >
> > - xa_for_each(&dist->lpi_xa, intid, irq) {
> > + xa_for_each_marked(&dist->lpi_xa, intid, irq, LPI_XA_MARK_DEBUG_ITER) {
> > xa_clear_mark(&dist->lpi_xa, intid, LPI_XA_MARK_DEBUG_ITER);
> > vgic_put_irq(kvm, irq);
> > }
>
> Ouch. Nicely caught. I think this deserves a
>
> Cc: stable@vger.kernel.org # v6.10

Yup. I guess Oliver will help to add it when applying ;-)

>
> With that,
>
> Reviewed-by: Marc Zyngier <maz@kernel.org>

Thanks!

Zenghui