Re: [PATCH 26/31] KVM: arm64: vgic-v3: Add ICV_DIR_EL1 handler

Auger Eric
2017-05-30T10:15:41Z

Marc,

On 03/05/2017 12:46, Marc Zyngier wrote:
> Add a handler for writing the guest's view of the ICC_DIR_EL1
> register, performing the deactivation of an interrupt if EOImode
> is set ot 1.
>
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
> virt/kvm/arm/hyp/vgic-v3-sr.c | 23 +++++++++++++++++++++++
> 1 file changed, 23 insertions(+)
>
> diff --git a/virt/kvm/arm/hyp/vgic-v3-sr.c b/virt/kvm/arm/hyp/vgic-v3-sr.c
> index 9c639f57268b..563dd2d16c59 100644
> --- a/virt/kvm/arm/hyp/vgic-v3-sr.c
> +++ b/virt/kvm/arm/hyp/vgic-v3-sr.c
> @@ -612,6 +612,26 @@ static void __hyp_text __vgic_v3_bump_eoicount(void)
> write_gicreg(hcr, ICH_HCR_EL2);
> }
>
> +static void __hyp_text __vgic_v3_write_dir(struct kvm_vcpu *vcpu,
> + u32 vmcr, int rt)
> +{
> + u32 vid = vcpu_get_reg(vcpu, rt);
> + u64 lr_val;
> + int lr;
> +
> + /* No deactivate to be performed on an LPI */
> + if (vid >= VGIC_MIN_LPI)
> + return;

don't you need to test the EOImode first? Spec says:
"
When EOImode == ‘0’. GICv3 implementations must ignore such writes. In
systems supporting system error generation, an implementation might
generate an SEI.
"

Thanks

Eric

> +
> + lr = __vgic_v3_find_active_lr(vcpu, vid, &lr_val);
> + if (lr == -1) {
> + __vgic_v3_bump_eoicount();
> + return;
> + }
> +
> + __vgic_v3_clear_active_lr(lr, lr_val);
> +}
> +
> static void __hyp_text __vgic_v3_write_eoir(struct kvm_vcpu *vcpu, u32 vmcr, int rt)
> {
> u32 vid = vcpu_get_reg(vcpu, rt);
> @@ -912,6 +932,9 @@ int __hyp_text __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu)
> else
> fn = __vgic_v3_write_bpr0;
> break;
> + case SYS_ICC_DIR_EL1:
> + fn = __vgic_v3_write_dir;
> + break;
> default:
> return 0;
> }
>