Re: [PATCH v3 54/59] KVM: arm/arm64: GICv4: Enable virtual cpuif if VLPIs can be delivered

Christoffer Dall
2017-08-28T18:18:35Z

On Mon, Jul 31, 2017 at 06:26:32PM +0100, Marc Zyngier wrote:
> In order for VLPIs to be delivered to the guest, we must make
> sure that the cpuif is always enabled, irrespective of the
> presence of virtual interrupt in the LRs.
>
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
> virt/kvm/arm/hyp/vgic-v3-sr.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/virt/kvm/arm/hyp/vgic-v3-sr.c b/virt/kvm/arm/hyp/vgic-v3-sr.c
> index 91728faa13fd..f5c3d6d7019e 100644
> --- a/virt/kvm/arm/hyp/vgic-v3-sr.c
> +++ b/virt/kvm/arm/hyp/vgic-v3-sr.c
> @@ -258,7 +258,8 @@ void __hyp_text __vgic_v3_save_state(struct kvm_vcpu *vcpu)
> cpu_if->vgic_ap1r[0] = __vgic_v3_read_ap1rn(0);
> }
> } else {
> - if (static_branch_unlikely(&vgic_v3_cpuif_trap))
> + if (static_branch_unlikely(&vgic_v3_cpuif_trap) ||
> + cpu_if->its_vpe.its_vm)
> write_gicreg(0, ICH_HCR_EL2);
>
> cpu_if->vgic_elrsr = 0xffff;
> @@ -337,9 +338,11 @@ void __hyp_text __vgic_v3_restore_state(struct kvm_vcpu *vcpu)
> /*
> * If we need to trap system registers, we must write
> * ICH_HCR_EL2 anyway, even if no interrupts are being
> - * injected,
> + * injected. Same thing if GICv4 is used, as VLPI
> + * delivery is gated by ICH_HCR_EL2.En.
> */
> - if (static_branch_unlikely(&vgic_v3_cpuif_trap))
> + if (static_branch_unlikely(&vgic_v3_cpuif_trap) ||
> + cpu_if->its_vpe.its_vm)
> write_gicreg(cpu_if->vgic_hcr, ICH_HCR_EL2);
> }
>
> --
> 2.11.0
>

Acked-by: Christoffer Dall <cdall@linaro.org>