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| author | Like Xu <likexu@tencent.com> | 2023-06-03 04:10:57 +0300 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2023-06-07 03:31:44 +0300 |
| commit | 4a2771895ca63a055df815be5e307cce8e85308c (patch) | |
| tree | e27fb5669aca01459be7ad6c975ddfec98a91c37 /arch/x86/kvm/x86.c | |
| parent | fe8d76c1a6f04387953727ee3e63469956e7360d (diff) | |
| download | linux-4a2771895ca63a055df815be5e307cce8e85308c.tar.xz | |
KVM: x86/svm/pmu: Add AMD PerfMonV2 support
If AMD Performance Monitoring Version 2 (PerfMonV2) is detected by
the guest, it can use a new scheme to manage the Core PMCs using the
new global control and status registers.
In addition to benefiting from the PerfMonV2 functionality in the same
way as the host (higher precision), the guest also can reduce the number
of vm-exits by lowering the total number of MSRs accesses.
In terms of implementation details, amd_is_valid_msr() is resurrected
since three newly added MSRs could not be mapped to one vPMC.
The possibility of emulating PerfMonV2 on the mainframe has also
been eliminated for reasons of precision.
Co-developed-by: Sandipan Das <sandipan.das@amd.com>
Signed-off-by: Sandipan Das <sandipan.das@amd.com>
Signed-off-by: Like Xu <likexu@tencent.com>
[sean: drop "Based on the observed HW." comments]
Link: https://lore.kernel.org/r/20230603011058.1038821-12-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c0778ca39650..abfba3cae0ba 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1483,6 +1483,10 @@ static const u32 msrs_to_save_pmu[] = { MSR_F15H_PERF_CTL3, MSR_F15H_PERF_CTL4, MSR_F15H_PERF_CTL5, MSR_F15H_PERF_CTR0, MSR_F15H_PERF_CTR1, MSR_F15H_PERF_CTR2, MSR_F15H_PERF_CTR3, MSR_F15H_PERF_CTR4, MSR_F15H_PERF_CTR5, + + MSR_AMD64_PERF_CNTR_GLOBAL_CTL, + MSR_AMD64_PERF_CNTR_GLOBAL_STATUS, + MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR, }; static u32 msrs_to_save[ARRAY_SIZE(msrs_to_save_base) + @@ -7150,6 +7154,12 @@ static void kvm_probe_msr_to_save(u32 msr_index) kvm_pmu_cap.num_counters_fixed) return; break; + case MSR_AMD64_PERF_CNTR_GLOBAL_CTL: + case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS: + case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR: + if (!kvm_cpu_cap_has(X86_FEATURE_PERFMON_V2)) + return; + break; case MSR_IA32_XFD: case MSR_IA32_XFD_ERR: if (!kvm_cpu_cap_has(X86_FEATURE_XFD)) |