[PATCH v2 09/26] arm64: Add feature detection for fine grained traps

[Miguel Luis]

Hi Marc,

> On 28 Jul 2023, at 08:29, 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
> ---
> 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

Reviewed-by: Miguel Luis <miguel.luis at oracle.com>

Thanks

Miguel

> HAS_GENERIC_AUTH
> HAS_GENERIC_AUTH_ARCH_QARMA3
> HAS_GENERIC_AUTH_ARCH_QARMA5
> -- 
> 2.34.1
>