[PATCH v2 5/7] KVM: arm64: Limit the debug architecture to ARMv8.0

[Alexandru Elisei]

Hi Marc,

This looks correct, and it also matches what we report for aarch32 in trap_dbgidr():

Reviewed-by: Alexandru Elisei <alexandru.elisei at arm.com>

On 1/25/21 12:26 PM, Marc Zyngier wrote:
> Let's not pretend we support anything but ARMv8.0 as far as the
> debug architecture is concerned.
>
> Reviewed-by: Eric Auger <eric.auger at redhat.com>
> Signed-off-by: Marc Zyngier <maz at kernel.org>
> ---
>  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,