Messages in this thread | | | From | Like Xu <> | Subject | [PATCH v2 0/3] KVM: x86: Add AMD Guest PerfMonV2 PMU support | Date | Mon, 19 Sep 2022 17:34:50 +0800 |
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Starting with Zen4, core PMU on AMD platforms such as Genoa and Ryzen-7000 will support PerfMonV2, and it is also compatible with legacy PERFCTR_CORE behavior and msr addresses.
If you don't have access to the hardware specification, the commits d6d0c7f681fd..7685665c390d for host perf can also bring a quick overview. Its main change is the addition of three msr's equivalent to Intel V2, namely global_ctrl, global_status, global_status_clear.
It is worth noting that this feature is very attractive for reducing the overhead of PMU virtualization, since multiple msr accesses to multiple counters will be replaced by a single access to the global register, plus more accuracy gain when multiple guest counters are used.
The KVM part is based on the latest vPMU fixes patch set [1], while the kvm-unit-test patch has been move to the preemptive test cases effort [2] for testing leagcy AMD vPMU, which didn't exist before.
All related testcases are passed on a Genoa box. Please feel free to run more tests, add more or share comments.
[1] https://lore.kernel.org/kvm/20220831085328.45489-1-likexu@tencent.com/ [2] https://lore.kernel.org/kvm/20220819110939.78013-1-likexu@tencent.com/
Previous: https://lore.kernel.org/kvm/20220905123946.95223-1-likexu@tencent.com/
V1 -> V2 Changelog: - The patch limiting the x86 GP counters is moved to specific patch set; - MSR scope is bounded by pmu->nr_arch_gp_counters (Jim); - Fn8000_0022_EBX can never report less than four counters \ (or six, if Fn8000_0001_ECX[PerfCtrExtCore] is set); (Jim) - Use "kvm_pmu_cap.version > 1" check instead of "guest perfmon_v2 bit";
Like Xu (2): KVM: x86/pmu: Make part of the Intel v2 PMU MSRs handling x86 generic KVM: x86/svm/pmu: Add AMD PerfMonV2 support
Sandipan Das (1): KVM: x86/cpuid: Add AMD CPUID ExtPerfMonAndDbg leaf 0x80000022
arch/x86/include/asm/kvm-x86-pmu-ops.h | 1 - arch/x86/include/asm/kvm_host.h | 1 + arch/x86/include/asm/perf_event.h | 8 +++ arch/x86/kvm/cpuid.c | 32 ++++++++++- arch/x86/kvm/pmu.c | 61 +++++++++++++++++++-- arch/x86/kvm/pmu.h | 30 +++++++++- arch/x86/kvm/svm/pmu.c | 76 +++++++++++++++++++------- arch/x86/kvm/vmx/pmu_intel.c | 58 +------------------- arch/x86/kvm/x86.c | 14 ++++- 9 files changed, 193 insertions(+), 88 deletions(-)
-- 2.37.3
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