[PATCH v3 09/27] arm64: Add feature detection for fine grained traps

[Jing Zhang]

Hi Marc,

On Tue, Aug 8, 2023 at 4:47 AM Marc Zyngier <maz at kernel.org> wrote:
>
> From: Mark Brown <broonie at kernel.org>
>
> In order to allow us to have shared code for managing fine grained traps
> for KVM guests add it as a detected feature rather than relying on it
> being a dependency of other features.
>
> Acked-by: Catalin Marinas <catalin.marinas at arm.com>
> Reviewed-by: Eric Auger <eric.auger at redhat.com>
> Signed-off-by: Mark Brown <broonie at kernel.org>
> [maz: converted to ARM64_CPUID_FIELDS()]
> Signed-off-by: Marc Zyngier <maz at kernel.org>
> Link: https://lore.kernel.org/r/20230301-kvm-arm64-fgt-v4-1-1bf8d235ac1f@kernel.org
> Reviewed-by: Zenghui Yu <yuzenghui at huawei.com>
> Reviewed-by: Miguel Luis <miguel.luis at oracle.com>
> ---
>  arch/arm64/kernel/cpufeature.c | 7 +++++++
>  arch/arm64/tools/cpucaps       | 1 +
>  2 files changed, 8 insertions(+)
>
> diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
> index f9d456fe132d..668e2872a086 100644
> --- a/arch/arm64/kernel/cpufeature.c
> +++ b/arch/arm64/kernel/cpufeature.c
> @@ -2627,6 +2627,13 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
>                 .matches = has_cpuid_feature,
>                 ARM64_CPUID_FIELDS(ID_AA64ISAR1_EL1, LRCPC, IMP)
>         },
> +       {
> +               .desc = "Fine Grained Traps",
> +               .type = ARM64_CPUCAP_SYSTEM_FEATURE,
> +               .capability = ARM64_HAS_FGT,
> +               .matches = has_cpuid_feature,
> +               ARM64_CPUID_FIELDS(ID_AA64MMFR0_EL1, FGT, IMP)
> +       },
>  #ifdef CONFIG_ARM64_SME
>         {
>                 .desc = "Scalable Matrix Extension",
> diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps
> index c80ed4f3cbce..c3f06fdef609 100644
> --- a/arch/arm64/tools/cpucaps
> +++ b/arch/arm64/tools/cpucaps
> @@ -26,6 +26,7 @@ HAS_ECV
>  HAS_ECV_CNTPOFF
>  HAS_EPAN
>  HAS_EVT
> +HAS_FGT
>  HAS_GENERIC_AUTH
>  HAS_GENERIC_AUTH_ARCH_QARMA3
>  HAS_GENERIC_AUTH_ARCH_QARMA5
> --
> 2.34.1
>
>

Reviewed-by: Jing Zhang <jingzhangos at google.com>