KVM: x86/pmu: Replace pmc_perf_hw_id() with perf_get_hw_event_config()

With the help of perf_get_hw_event_config(), KVM could query the correct
EVENTSEL_{EVENT, UMASK} pair of a kernel-generic hw event directly from
the different *_perfmon_event_map[] by the kernel's pre-defined perf_hw_id.

Also extend the bit range of the comparison field to
AMD64_RAW_EVENT_MASK_NB to prevent AMD from
defining EventSelect[11:8] into perfmon_event_map[] one day.

Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20220518132512.37864-11-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index b46a96604fe62b1f16f58f8a58bbe20f53883b9e..2843ce35c8d9143e453630aca9dc6474f34c8ca0 100644 (file)
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -525,13 +525,8 @@ static void kvm_pmu_incr_counter(struct kvm_pmc *pmc)
 static inline bool eventsel_match_perf_hw_id(struct kvm_pmc *pmc,
        unsigned int perf_hw_id)
 {
-       u64 old_eventsel = pmc->eventsel;
-       unsigned int config;
-
-       pmc->eventsel &= (ARCH_PERFMON_EVENTSEL_EVENT | ARCH_PERFMON_EVENTSEL_UMASK);
-       config = static_call(kvm_x86_pmu_pmc_perf_hw_id)(pmc);
-       pmc->eventsel = old_eventsel;
-       return config == perf_hw_id;
+       return !((pmc->eventsel ^ perf_get_hw_event_config(perf_hw_id)) &
+               AMD64_RAW_EVENT_MASK_NB);
 }
 
 static inline bool cpl_is_matched(struct kvm_pmc *pmc)