Re: [PATCH] KVM: arm64: fix potential bug
From: Gong John
Date: Mon Mar 11 2019 - 23:16:11 EST
On Tue, Mar 12, 2019 at 9:44 AM AndrÃ Przywara <andre.przywara@xxxxxxx> wrote:
> On 12/03/2019 00:32, John Gong wrote:
> > Since intid always >= VGIC_NR_PRIVATE_IRQS,
> How so? The PMU and the arch timer emulation use PPIs, so intid is
> definitely < VGIC_NR_PRIVATE_IRQS there.
> > so then even vcpu == NULL, it never return -EINVAL.
> I am not sure I follow.
> To uniquely identify an SPI interrupt, we just need the interrupt ID
> (which is always >= 32). For PPIs and SGIs, we additionally need the
> vCPU ID this private interrupt belongs to, as there are multiple
> interrupts with the same INTID (one per VCPU).
> The VCPU ID passed in for SPIs is just a dummy value (because we use the
> same function to inject private and shared interrupts), so we don't need
> to check for its validity.
Thanks for your explanation. It's my fault to not consider the PPIs
and SGIs injection.
Sorry for polluting the mail list.
> > Signed-off-by: Shengmin Gong <shengmin.gong@xxxxxxxxx>
> > Signed-off-by: John Gong <johngong0791@xxxxxxxxx>
> > ---
> > virt/kvm/arm/vgic/vgic.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> > diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
> > index abd9c7352677..d3cb1ce880e2 100644
> > --- a/virt/kvm/arm/vgic/vgic.c
> > +++ b/virt/kvm/arm/vgic/vgic.c
> > @@ -424,7 +424,7 @@ int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int intid,
> > return ret;
> > vcpu = kvm_get_vcpu(kvm, cpuid);
> > - if (!vcpu && intid < VGIC_NR_PRIVATE_IRQS)
> > + if (!vcpu)
> > return -EINVAL;
> > irq = vgic_get_irq(kvm, vcpu, intid);