On Tue, Jul 29, 2025 at 09:56:12AM -0700, Raghavendra Rao Ananta wrote:
> On Tue, Jul 29, 2025 at 7:37 AM Oliver Upton <oliver.upton@xxxxxxxxx> wrote:
> >
> > Hi Raghu,
> >
> > Thanks for reporting this so quickly :)
> >
> > On Mon, Jul 28, 2025 at 10:37:10PM +0000, Raghavendra Rao Ananta wrote:
> > > diff --git a/arch/arm64/kvm/vgic/vgic-v4.c b/arch/arm64/kvm/vgic/vgic-v4.c
> > > index e7e284d47a77..873a190bcff7 100644
> > > --- a/arch/arm64/kvm/vgic/vgic-v4.c
> > > +++ b/arch/arm64/kvm/vgic/vgic-v4.c
> > > @@ -433,7 +433,7 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
> > > unsigned long flags;
> > > int ret = 0;
> > >
> > > - if (!vgic_supports_direct_msis(kvm))
> > > + if (!vgic_supports_direct_irqs(kvm))
> > > return 0;
> > >
> > > /*
> > > @@ -533,7 +533,7 @@ int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int host_irq)
> > > unsigned long flags;
> > > int ret = 0;
> > >
> > > - if (!vgic_supports_direct_msis(kvm))
> > > + if (!vgic_supports_direct_irqs(kvm))
> > > return 0;
> >
> > I'm not sure this is what we want, since a precondition of actually
> > doing vLPI injection is the guest having an ITS. Could you try the
> > following?
> >
> > Thanks,
> > Oliver
> >
> > diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
> > index a3ef185209e9..70d50c77e5dc 100644
> > --- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c
> > +++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
> > @@ -50,6 +50,14 @@ bool vgic_has_its(struct kvm *kvm)
> >
> > bool vgic_supports_direct_msis(struct kvm *kvm)
> > {
> > + /*
> > + * Deliberately conflate vLPI and vSGI support on GICv4.1 hardware,
> > + * indirectly allowing userspace to control whether or not vPEs are
> > + * allocated for the VM.
> > + */
> > + if (system_supports_direct_sgis() && !vgic_supports_direct_sgis(kvm))
> > + return false;
> > +
> > return kvm_vgic_global_state.has_gicv4 && vgic_has_its(kvm);
> > }
> >
> > diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
> > index 1384a04c0784..de1c1d3261c3 100644
> > --- a/arch/arm64/kvm/vgic/vgic.h
> > +++ b/arch/arm64/kvm/vgic/vgic.h
> > @@ -396,15 +396,7 @@ bool vgic_supports_direct_sgis(struct kvm *kvm);
> >
> > static inline bool vgic_supports_direct_irqs(struct kvm *kvm)
> > {
> > - /*
> > - * Deliberately conflate vLPI and vSGI support on GICv4.1 hardware,
> > - * indirectly allowing userspace to control whether or not vPEs are
> > - * allocated for the VM.
> > - */
> > - if (system_supports_direct_sgis())
> > - return vgic_supports_direct_sgis(kvm);
> > -
> > - return vgic_supports_direct_msis(kvm);
> > + return vgic_supports_direct_msis(kvm) || vgic_supports_direct_sgis(kvm);
> > }
> >
> > int vgic_v4_init(struct kvm *kvm);
>
> Yes, the diff seems fine (tested as well). Would you be pushing a v2
> or do you want me to (on your behalf)?
Go ahead and respin this diff, thanks!
Oliver
