[v9,00/28] KVM: x86/pmu: selftests: Fixes and new tests

Message

Sean Christopherson Dec. 2, 2023, 12:03 a.m. UTC

Yet another version of fixes and tests for PMU counters.  New in v9 is a
fix for priority inversion of #GP vs. VM-Exit on Intel when KVM fully
emulates a RDPMC with a "bad" index.  For all intents and purposes, this
priority inversion triggered the WARN in v8[*], which is why I included
the fix in this series (and because the fix would conflict horribly).

Dapeng, I dropped one of your reviews (patch "Disallow "fast" RDPMC for
architectural Intel PMUs) as the patch ended up being quite different after
eliminating the early RDPMC index check.

[*] https://lore.kernel.org/all/[e-mail]

v9:
 - Collect reviews. [Dapeng, Kan]
 - Fix a 63:31 => 63:32 typo in a changelog. [Dapeng]
 - Actually check that forced emulation is enabled before trying to force
   emulation on RDPMC. [Jinrong]
 - Fix the aformentioned priority inversion issue.
 - Completely drop "support" for fast RDPMC, in quotes because KVM doesn't
   actually support RDPMC for non-architectural PMUs.  I had left the code
   in v8 because I didn't fully grok what the early emulator check was
   doing, i.e. wasn't 100% confident it was dead code.

v8:
 - https://lore.kernel.org/all/[e-mail]
 - Collect reviews. [Jim, Dapeng, Kan]
 - Tweak names for the RDPMC flags in the selftests #defines.
 - Get the event selectors used to virtualize fixed straight from perf
   instead of hardcoding the (wrong) selectors in KVM. [Kan]
 - Rename an "eventsel" field to "event" for a patch that gets blasted
   away in the end anyways. [Jim]
 - Add patches to fix RDPMC emulation and to test the behavior on Intel.
   I spot tested on AMD and spent ~30 minutes trying to squeeze in the
   bare minimum AMD support, but the PMU implementations between Intel
   and AMD are juuuust different enough to make adding AMD support non-
   trivial, and this series is already way too big.
 
v7:
 - https://lore.kernel.org/all/[e-mail]
 - Drop patches that unnecessarily sanitized supported CPUID. [Jim]
 - Purge the array of architectural event encodings. [Jim, Dapeng]
 - Clean up pmu.h to remove useless macros, and make it easier to use the
   new macros. [Jim]
 - Port more of pmu_event_filter_test.c to pmu.h macros. [Jim, Jinrong]
 - Clean up test comments and error messages. [Jim]
 - Sanity check the value provided to vcpu_set_cpuid_property(). [Jim]

v6:
 - https://lore.kernel.org/all/[e-mail]
 - Test LLC references/misses with CFLUSH{OPT}. [Jim]
 - Make the tests play nice without PERF_CAPABILITIES. [Mingwei]
 - Don't squash eventsels that happen to match an unsupported arch event. [Kan]
 - Test PMC counters with forced emulation (don't ask how long it took me to
   figure out how to read integer module params).

v5: https://lore.kernel.org/all/[e-mail]
v4: https://lore.kernel.org/all/[e-mail]
v3: https://lore.kernel.org/kvm/[e-mail]

Jinrong Liang (7):
  KVM: selftests: Add vcpu_set_cpuid_property() to set properties
  KVM: selftests: Add pmu.h and lib/pmu.c for common PMU assets
  KVM: selftests: Test Intel PMU architectural events on gp counters
  KVM: selftests: Test Intel PMU architectural events on fixed counters
  KVM: selftests: Test consistency of CPUID with num of gp counters
  KVM: selftests: Test consistency of CPUID with num of fixed counters
  KVM: selftests: Add functional test for Intel's fixed PMU counters

Sean Christopherson (21):
  KVM: x86/pmu: Always treat Fixed counters as available when supported
  KVM: x86/pmu: Allow programming events that match unsupported arch
    events
  KVM: x86/pmu: Remove KVM's enumeration of Intel's architectural
    encodings
  KVM: x86/pmu: Setup fixed counters' eventsel during PMU initialization
  KVM: x86/pmu: Get eventsel for fixed counters from perf
  KVM: x86/pmu: Don't ignore bits 31:30 for RDPMC index on AMD
  KVM: x86/pmu: Prioritize VMX interception over #GP on RDPMC due to bad
    index
  KVM: x86/pmu: Apply "fast" RDPMC only to Intel PMUs
  KVM: x86/pmu: Disallow "fast" RDPMC for architectural Intel PMUs
  KVM: x86/pmu: Explicitly check for RDPMC of unsupported Intel PMC
    types
  KVM: selftests: Drop the "name" param from KVM_X86_PMU_FEATURE()
  KVM: selftests: Extend {kvm,this}_pmu_has() to support fixed counters
  KVM: selftests: Expand PMU counters test to verify LLC events
  KVM: selftests: Add a helper to query if the PMU module param is
    enabled
  KVM: selftests: Add helpers to read integer module params
  KVM: selftests: Query module param to detect FEP in MSR filtering test
  KVM: selftests: Move KVM_FEP macro into common library header
  KVM: selftests: Test PMC virtualization with forced emulation
  KVM: selftests: Add a forced emulation variation of KVM_ASM_SAFE()
  KVM: selftests: Add helpers for safe and safe+forced RDMSR, RDPMC, and
    XGETBV
  KVM: selftests: Extend PMU counters test to validate RDPMC after WRMSR

 arch/x86/include/asm/kvm-x86-pmu-ops.h        |   3 +-
 arch/x86/kvm/emulate.c                        |   2 +-
 arch/x86/kvm/kvm_emulate.h                    |   2 +-
 arch/x86/kvm/pmu.c                            |  20 +-
 arch/x86/kvm/pmu.h                            |   5 +-
 arch/x86/kvm/svm/pmu.c                        |  17 +-
 arch/x86/kvm/vmx/pmu_intel.c                  | 157 ++---
 arch/x86/kvm/x86.c                            |   9 +-
 tools/testing/selftests/kvm/Makefile          |   2 +
 .../selftests/kvm/include/kvm_util_base.h     |   4 +
 tools/testing/selftests/kvm/include/pmu.h     |  97 +++
 .../selftests/kvm/include/x86_64/processor.h  | 148 ++++-
 tools/testing/selftests/kvm/lib/kvm_util.c    |  62 +-
 tools/testing/selftests/kvm/lib/pmu.c         |  31 +
 .../selftests/kvm/lib/x86_64/processor.c      |  15 +-
 .../selftests/kvm/x86_64/pmu_counters_test.c  | 617 ++++++++++++++++++
 .../kvm/x86_64/pmu_event_filter_test.c        | 143 ++--
 .../smaller_maxphyaddr_emulation_test.c       |   2 +-
 .../kvm/x86_64/userspace_msr_exit_test.c      |  29 +-
 .../selftests/kvm/x86_64/vmx_pmu_caps_test.c  |   2 +-
 20 files changed, 1079 insertions(+), 288 deletions(-)
 create mode 100644 tools/testing/selftests/kvm/include/pmu.h
 create mode 100644 tools/testing/selftests/kvm/lib/pmu.c
 create mode 100644 tools/testing/selftests/kvm/x86_64/pmu_counters_test.c


base-commit: 9f018b692c0114a484cea4faf9758a224774866a