RE: [RFC v1 1/9] KVM: x86: Add base address parameter for get_fixed_pmc function

From: Kang, Luwei
Date: Thu Aug 29 2019 - 20:15:36 EST


> > /* returns fixed PMC with the specified MSR */ -static inline struct
> > kvm_pmc *get_fixed_pmc(struct kvm_pmu *pmu, u32 msr)
> > +static inline struct kvm_pmc *get_fixed_pmc(struct kvm_pmu *pmu, u32
> msr,
> > + int base)
>
> Better define a __get_fixed_pmc just for this case, with the existing
> get_fixed_pmc being a wrapper.
>
> This would avoid changing all the callers below.

Do you mean change the code like this, and call "__get_fixed_pmc" in my patch? We already have a similar function to get gp counters.
struct kvm_pmc *get_gp_pmc(struct kvm_pmu *pmu, u32 msr, u32 base) // get gp counters
struct kvm_pmc *get_fixed_pmc(struct kvm_pmu *pmu, u32 msr) // get fixed counters

-/* returns fixed PMC with the specified MSR */
-static inline struct kvm_pmc *get_fixed_pmc(struct kvm_pmu *pmu, u32 msr)
+static inline struct kvm_pmc *__get_fixed_pmc(struct kvm_pmu *pmu, u32 msr, u32 base)
{
- int base = MSR_CORE_PERF_FIXED_CTR0;
-
if (msr >= base && msr < base + pmu->nr_arch_fixed_counters)
return &pmu->fixed_counters[msr - base];

return NULL;
}

+/* returns fixed PMC with the specified MSR */
+static inline struct kvm_pmc *get_fixed_pmc(struct kvm_pmu *pmu, u32 msr)
+{
+ return __get_fixed_pmc(pmu, msr, MSR_CORE_PERF_FIXED_CTR0)
+}

Thanks,
Luwei Kang

>
>
> -Andi