On Tue, May 30, 2023, Like Xu wrote:
> From: Like Xu <likexu@xxxxxxxxxxx>
>
> AMD PerfMonV2 defines three registers similar to part of the Intel
> v2 PMU registers, including the GLOBAL_CTRL, GLOBAL_STATUS and
> GLOBAL_OVF_CTRL MSRs. For better code reuse, this specific part of
> the handling can be extracted to make it generic for X86 as a straight
> code movement.
>
> Specifically, the kvm_pmu_set/get_msr() handlers of GLOBAL_STATUS,
> GLOBAL_CTRL, GLOBAL_OVF_CTRL defined for Intel are moved to generic
> pmu.c and the callback function .pmc_is_globally_enabled is removed,
> which is very helpful to introduce the AMD PerfMonV2 code later.
Yeah, except this patch doesn't actually move anything. *Some* of the common bits
show up in pmu.c, but the same bits in pmu_intel.c get left behind.
> The new eponymous pmc_is_globally_enabled() works well as legacy AMD
> vPMU version is indexed as 1. Note that the specific *_is_valid_msr will
> continue to be used to avoid cross-vendor MSR access.
This should be two patches. Moving the GLOBAL_CTRL stuff is logically separate
from moving the pmc_is_enabled() code.
> Signed-off-by: Like Xu <likexu@xxxxxxxxxxx>
> ---
> @@ -213,6 +212,22 @@ static inline void reprogram_counters(struct kvm_pmu *pmu, u64 diff)
> kvm_make_request(KVM_REQ_PMU, pmu_to_vcpu(pmu));
> }
>
> +/*
> + * Check if a PMC is enabled by comparing it against global_ctrl bits.
> + *
> + * If the current version of vPMU doesn't have global_ctrl MSR,
> + * all vPMCs are enabled (return TRUE).
> + */
> +static inline bool pmc_is_globally_enabled(struct kvm_pmc *pmc)
> +{
> + struct kvm_pmu *pmu = pmc_to_pmu(pmc);
> +
> + if (pmu->version < 2)
Nah, we're not open coding this check, not after putting in the effort to squash
the mess of open coding on Intel. Moving intel_pmu_has_perf_global_ctrl() is
trivial, and also allows moving the existence checks into kvm_pmu_is_valid_msr().
