Re: [PATCH v21 12/15] KVM: selftests: arm64: Add GCS to set_id_regs

["Lorenzo Stoakes (ARM)" <ljs@kernel.org>]

On Wed, Sep 30, 2026 at 10:48:22PM +0100, Mark Brown wrote:
> Now that GCS is configurable via the ID registers update set_id_regs to
> cover ID_AA64PFR1_EL1.GCS.

Should maybe also mention adding the GCS-without-S1PIE test?

>
> Signed-off-by: Mark Brown <broonie@kernel.org>

Looks obviously correct (TM) to me too so:

Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>

> ---
>  tools/testing/selftests/kvm/arm64/set_id_regs.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/tools/testing/selftests/kvm/arm64/set_id_regs.c b/tools/testing/selftests/kvm/arm64/set_id_regs.c
> index cb5e6358c59c..9db8516748cc 100644
> --- a/tools/testing/selftests/kvm/arm64/set_id_regs.c
> +++ b/tools/testing/selftests/kvm/arm64/set_id_regs.c
> @@ -154,6 +154,7 @@ static const struct reg_ftr_bits ftr_id_aa64pfr0_el1[] = {
>
>  static const struct reg_ftr_bits ftr_id_aa64pfr1_el1[] = {
>  	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR1_EL1, DF2, 0),
> +	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR1_EL1, GCS, 0),
>  	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR1_EL1, CSV2_frac, 0),
>  	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR1_EL1, SSBS, ID_AA64PFR1_EL1_SSBS_NI),
>  	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR1_EL1, BT, 0),
> @@ -818,6 +819,12 @@ struct reg_ftr_val {
>  	  .mask = r ## _ ## f ## _MASK,				\
>  	  .val = (r ## _ ## f ## _ ## v  << r ## _ ## f ## _SHIFT) }
>
> +static const struct reg_ftr_val gcs_no_s1pie[] = {
> +	REG_FTR_VAL(ID_AA64PFR1_EL1, GCS, IMP),
> +	REG_FTR_VAL(ID_AA64MMFR3_EL1, S1PIE, NI),
> +	{ }
> +};
> +
>  static const struct reg_ftr_val s1pie_no_tcr2[] = {
>  	REG_FTR_VAL(ID_AA64MMFR3_EL1, TCRX, NI),
>  	REG_FTR_VAL(ID_AA64MMFR3_EL1, S1PIE, IMP),
> @@ -836,6 +843,7 @@ struct ftr_config {
>  };
>
>  static const struct ftr_config invalid_configs[] = {
> +	{ .name = "GCS without S1PIE", .regs = gcs_no_s1pie },
>  	{ .name = "S1PIE without TCRX", .regs = s1pie_no_tcr2 },
>  	{ .name = "S1POE without TCRX", .regs = s1poe_no_tcr2 },
>  };
>
> --
> 2.47.3
>
>

--
Cheers, Lorenzo