Re: [PATCH 11/31] KVM: arm64: vgic-v3: Add ICV_BPR1_EL1 handler

Auger Eric
2017-05-17T15:35:59Z

Hi,

On 03/05/2017 12:45, Marc Zyngier wrote:
> Add a handler for reading/writing the guest's view of the ICC_BPR1_EL1
> register, which is located in the ICH_VMCR_EL2.BPR1 field.
>
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
> virt/kvm/arm/hyp/vgic-v3-sr.c | 61 ++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 60 insertions(+), 1 deletion(-)
>
> diff --git a/virt/kvm/arm/hyp/vgic-v3-sr.c b/virt/kvm/arm/hyp/vgic-v3-sr.c
> index 435787a93c6c..f0f038c490a5 100644
> --- a/virt/kvm/arm/hyp/vgic-v3-sr.c
> +++ b/virt/kvm/arm/hyp/vgic-v3-sr.c
> @@ -375,9 +375,57 @@ void __hyp_text __vgic_v3_write_vmcr(u32 vmcr)
>
> #ifdef CONFIG_ARM64
>
> +static unsigned int __hyp_text __vgic_v3_get_bpr0(u32 vmcr)
> +{
> + return (vmcr & ICH_VMCR_BPR0_MASK) >> ICH_VMCR_BPR0_SHIFT;
> +}
> +
> +static unsigned int __hyp_text __vgic_v3_get_bpr1(u32 vmcr)
> +{
> + unsigned int bpr;
> +
> + if (vmcr & ICH_VMCR_CBPR_MASK) {
> + bpr = __vgic_v3_get_bpr0(vmcr);
> + if (bpr < 7)
> + bpr++;
> + } else {
> + bpr = (vmcr & ICH_VMCR_BPR1_MASK) >> ICH_VMCR_BPR1_SHIFT;
> + }
> +
> + return bpr;
> +}
> +
> +static void __hyp_text __vgic_v3_read_bpr1(struct kvm_vcpu *vcpu, u32 vmcr, int rt)
> +{
> + vcpu_set_reg(vcpu, rt, __vgic_v3_get_bpr1(vmcr));
> +}
> +
> +static void __hyp_text __vgic_v3_write_bpr1(struct kvm_vcpu *vcpu, u32 vmcr, int rt)
> +{
> + u64 val = vcpu_get_reg(vcpu, rt);
> + u8 bpr_min = 8 - vtr_to_nr_pre_bits(read_gicreg(ICH_VTR_EL2));
> +
> + if (vmcr & ICH_VMCR_CBPR_MASK)
> + return;
> +
> + /* Enforce BPR limiting */
> + if (val < bpr_min)
> + val = bpr_min;
> +
> + val <<= ICH_VMCR_BPR1_SHIFT;
> + val &= ICH_VMCR_BPR1_MASK;
> + vmcr &= ~ICH_VMCR_BPR1_MASK;
> + vmcr |= val;
> +
> + __vgic_v3_write_vmcr(vmcr);
> +}
> +
> int __hyp_text __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu)
> {
> - u32 esr = kvm_vcpu_get_hsr(vcpu);
> + int rt = kvm_vcpu_sys_get_rt(vcpu);
nit: could be done later when setting is_read.

> + u32 vmcr, esr = kvm_vcpu_get_hsr(vcpu);
Christoffer does not like this ;-)

Besides looks good to me

Reviewed-by: Eric Auger <eric.auger@redhat.com>

Thanks

Eric

> + void (*fn)(struct kvm_vcpu *, u32, int);
> + bool is_read;
> u32 sysreg;
>
> if (vcpu_mode_is_32bit(vcpu)) {
> @@ -389,11 +437,22 @@ int __hyp_text __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu)
> sysreg = esr_sys64_to_sysreg(esr);
> }
>
> + is_read = (esr & ESR_ELx_SYS64_ISS_DIR_MASK) == ESR_ELx_SYS64_ISS_DIR_READ;
> +
> switch (sysreg) {
> + case SYS_ICC_BPR1_EL1:
> + if (is_read)
> + fn = __vgic_v3_read_bpr1;
> + else
> + fn = __vgic_v3_write_bpr1;
> + break;
> default:
> return 0;
> }
>
> + vmcr = __vgic_v3_read_vmcr();
> + fn(vcpu, vmcr, rt);
> +
> return 1;
> }
>
>