[PATCH v11 5/5] KVM: arm64: Refactor writings for PMUVer/CSV2/CSV3

[Jitindar Singh, Suraj]

On Fri, 2023-06-02 at 00:51 +0000, Jing Zhang wrote:
> Refactor writings for ID_AA64PFR0_EL1.[CSV2|CSV3],
> ID_AA64DFR0_EL1.PMUVer and ID_DFR0_ELF.PerfMon based on utilities
> specific to ID register.
> 
> Signed-off-by: Jing Zhang <jingzhangos at google.com>
> ---
>  arch/arm64/include/asm/cpufeature.h |   1 +
>  arch/arm64/kernel/cpufeature.c      |   2 +-
>  arch/arm64/kvm/sys_regs.c           | 291 +++++++++++++++++++-------
> --
>  3 files changed, 203 insertions(+), 91 deletions(-)
> 
> 
> +
> +static u64 read_sanitised_id_dfr0_el1(struct kvm_vcpu *vcpu,
> +                                     const struct sys_reg_desc *rd)
> +{
> +       u64 val;
> +       u32 id = reg_to_encoding(rd);
> +
> +       val = read_sanitised_ftr_reg(id);
> +       /*
> +        * Initialise the default PMUver before there is a chance to
> +        * create an actual PMU.
> +        */
> +       val &= ~ARM64_FEATURE_MASK(ID_DFR0_EL1_PerfMon);
> +       val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_DFR0_EL1_PerfMon),
> kvm_arm_pmu_get_pmuver_limit());

Maybe it's never possible, but does this need a:
pmuver_to_perfmon(kvm_arm_pmu_get_pmuver_limit()) ?

> +
> +       return val;
>  }
>  
>  
Thanks
- Suraj