[PATCH v6 00/10] KVM: x86: Add AMD Guest PerfMonV2 PMU support

[Like Xu <like.xu.linux@gmail.com>]

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.

All related testcases are passed on a Genoa box.
Please feel free to run more tests, add more or share comments.

Patch 0001-0007 could be applied earlier, which may help reduce
the burden on industrious reviewers.

Previous:
https://lore.kernel.org/kvm/20230214050757.9623-1-likexu@tencent.com/

V5 -> V6 Changelog:
- Introduce pmu_ops->MIN_NR_GP_COUNTERS and WARN_ON_ONCE; (Sean)
- Set MIN_NR_GP_COUNTERS = 2 instead of 1 for Intel Arch PMU;

Like Xu (10):
  KVM: x86/pmu: Expose reprogram_counters() in pmu.h
  KVM: x86/pmu: Return #GP if user sets the GLOBAL_STATUS reserved bits
  KVM: x86/pmu: Make part of the Intel v2 PMU MSRs handling x86 generic
  KVM: x86: Explicitly zero cpuid "0xa" leaf when PMU is disabled
  KVM: x86/pmu: Disable vPMU if the minimum num of counters isn't met
  KVM: x86/pmu: Forget PERFCTR_CORE if the min num of counters isn't met
  KVM: x86/pmu: Constrain the num of guest counters with kvm_pmu_cap
  KVM: x86/cpuid: Add a KVM-only leaf to redirect AMD PerfMonV2 flag
  KVM: x86/svm/pmu: Add AMD PerfMonV2 support
  KVM: x86/cpuid: Add AMD CPUID ExtPerfMonAndDbg leaf 0x80000022

 arch/x86/include/asm/kvm-x86-pmu-ops.h |  1 -
 arch/x86/kvm/cpuid.c                   | 30 +++++++++-
 arch/x86/kvm/pmu.c                     | 83 +++++++++++++++++++++++---
 arch/x86/kvm/pmu.h                     | 43 +++++++++++--
 arch/x86/kvm/reverse_cpuid.h           |  7 +++
 arch/x86/kvm/svm/pmu.c                 | 68 +++++++++++++++------
 arch/x86/kvm/svm/svm.c                 | 19 +++++-
 arch/x86/kvm/vmx/pmu_intel.c           | 33 +++-------
 arch/x86/kvm/x86.c                     | 10 ++++
 9 files changed, 230 insertions(+), 64 deletions(-)


base-commit: b9846a698c9aff4eb2214a06ac83638ad098f33f
-- 
2.40.1