Re: [PATCH 04/12] KVM: arm64: Force GICv3 traps activa when no irqchip is configured on VHE

Oliver Upton
2024-08-21T16:52:39Z

On Wed, Aug 21, 2024 at 12:13:57PM +0100, Marc Zyngier wrote:
> On Wed, 21 Aug 2024 00:33:40 +0100,
> Oliver Upton <oliver.upton@linux.dev> wrote:
> >
> > s/activa/active/
> >
> > On Tue, Aug 20, 2024 at 11:03:41AM +0100, Marc Zyngier wrote:
> > > On a VHE system, no GICv3 traps get configured when no irqchip is
> > > present. This is not quite matching the "no GICv3" semantics that
> > > we want to present.
> > >
> > > Force such traps to be configured in this case.
> > >
> > > Signed-off-by: Marc Zyngier <maz@kernel.org>
> > > ---
> > > arch/arm64/kvm/vgic/vgic.c | 14 ++++++++++----
> > > 1 file changed, 10 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c
> > > index 974849ea7101..2caa64415ff3 100644
> > > --- a/arch/arm64/kvm/vgic/vgic.c
> > > +++ b/arch/arm64/kvm/vgic/vgic.c
> > > @@ -917,10 +917,13 @@ void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
> > >
> > > void kvm_vgic_load(struct kvm_vcpu *vcpu)
> > > {
> > > - if (unlikely(!vgic_initialized(vcpu->kvm)))
> > > + if (unlikely(!irqchip_in_kernel(vcpu->kvm) || !vgic_initialized(vcpu->kvm))) {
> >
> > Doesn't !vgic_initialized(vcpu->kvm) also cover the case of no irqchip
> > in kernel?
>
> It does, but that's purely accidental. I can drop that, but it is
> really fragile.

Oh, definitely not, I was just wondering if this was meant as a
functional change or a readability change to make the relation explicit.

--
Thanks,
Oliver