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

[Jing Zhang]

On Fri, Jun 2, 2023 at 12:22 PM Jitindar Singh, Suraj
<surajjs at amazon.com> wrote:
>
> 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()) ?
Yes, will fix it and also update the comment above it.
>
> > +
> > +       return val;
> >  }
> >
> >
> Thanks
> - Suraj
Thanks,
Jing