Re: [PATCH v10 00/29] KVM: x86/pmu: selftests: Fixes and new tests

From: Mi, Dapeng
Date: Fri Jan 12 2024 - 04:17:33 EST



On 1/10/2024 7:02 AM, Sean Christopherson wrote:
Knock wood, _this_ is the final of fixes and tests for PMU counters. New
in v10 is a small refactor to treat FIXED as a value, not a flag, when
emulating RDPMC. Everything else is the same as v9 (although rebased, but
there were no conflicts).

v10:
- Collect review. [Dapeng]
- Treat the FIXED type in RDPMC's ECX as a value, not a flag. [Jim]

v9:
- https://lore.kernel.org/all/20231202000417.922113-1-seanjc@xxxxxxxxxx
- 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/20231110021306.1269082-1-seanjc@xxxxxxxxxx
- 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/20231108003135.546002-1-seanjc@xxxxxxxxxx
- 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/20231104000239.367005-1-seanjc@xxxxxxxxxx
- 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/20231024002633.2540714-1-seanjc@xxxxxxxxxx
v4: https://lore.kernel.org/all/20230911114347.85882-1-cloudliang@xxxxxxxxxxx
v3: https://lore.kernel.org/kvm/20230814115108.45741-1-cloudliang@xxxxxxxxxxx

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 (22):
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: Treat "fixed" PMU type in RDPMC as index as a value, not
flag
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 | 178 +++--
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, 1097 insertions(+), 291 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: 1c6d984f523f67ecfad1083bb04c55d91977bb15

pmu_counters_test passes on Intel Sapphire Rapids platform.

Tested-by:  Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>