Re: [PATCH v3 05/12] KVM: arm/arm64: Revisit Redistributor TYPER last bit computation

Christoffer Dall
2018-04-24T21:06:55Z

On Fri, Apr 13, 2018 at 10:20:51AM +0200, Eric Auger wrote:
> The TYPER of an redistributor reflects whether the rdist is
> the last one of the redistributor region. Let's compare the TYPER
> GPA against the address of the last occupied slot within the
> redistributor region.
>
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> ---
> virt/kvm/arm/vgic/vgic-mmio-v3.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> index 49ca176..ce5c927 100644
> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> @@ -184,12 +184,17 @@ static unsigned long vgic_mmio_read_v3r_typer(struct kvm_vcpu *vcpu,
> gpa_t addr, unsigned int len)
> {
> unsigned long mpidr = kvm_vcpu_get_mpidr_aff(vcpu);
> + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
> + struct vgic_redist_region *rdreg = vgic_cpu->rdreg;
> int target_vcpu_id = vcpu->vcpu_id;
> + gpa_t last_rdist_typer = rdreg->base + GICR_TYPER +
> + (rdreg->free_index - 1) * KVM_VGIC_V3_REDIST_SIZE;
> u64 value;
>
> value = (u64)(mpidr & GENMASK(23, 0)) << 32;
> value |= ((target_vcpu_id & 0xffff) << 8);
> - if (target_vcpu_id == atomic_read(&vcpu->kvm->online_vcpus) - 1)
> +
> + if (addr == last_rdist_typer)
> value |= GICR_TYPER_LAST;
> if (vgic_has_its(vcpu->kvm))
> value |= GICR_TYPER_PLPIS;
> --
> 2.5.5
>

Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>