Re: [PATCH 5/6] KVM: arm64: Limit the debug architecture to ARMv8.0

Auger Eric
2021-01-15T14:03:38Z

Hi Marc,

On 1/14/21 11:56 AM, Marc Zyngier wrote:
> Let's not pretend we support anything but ARMv8.0 as far as the
> debug architecture is concerned.
>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>

Eric
> ---
> arch/arm64/kvm/sys_regs.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> index dda16d60197b..8f79ec1fffa7 100644
> --- a/arch/arm64/kvm/sys_regs.c
> +++ b/arch/arm64/kvm/sys_regs.c
> @@ -1048,6 +1048,9 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu,
> FEATURE(ID_AA64ISAR1_GPI));
> break;
> case SYS_ID_AA64DFR0_EL1:
> + /* Limit debug to ARMv8.0 */
> + val &= ~FEATURE(ID_AA64DFR0_DEBUGVER);
> + val |= FIELD_PREP(FEATURE(ID_AA64DFR0_DEBUGVER), 6);
> /* Limit guests to PMUv3 for ARMv8.1 */
> val = cpuid_feature_cap_perfmon_field(val,
> ID_AA64DFR0_PMUVER_SHIFT,
>