| Message ID | 20240308223702.1350851-6-seanjc@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [GIT,PULL] KVM: x86: PMU changes for 6.9 | expand |
On 3/8/24 23:36, Sean Christopherson wrote: > Lots of PMU fixes and cleanups, along with related selftests. The most notable > fix is to *not* disallow the use of fixed counters and event encodings just > because the CPU doesn't report support for the matching architectural event > encoding. > > Note, the selftests changes have several annoying conflicts with "the" selftests > pull request that you'll also receive from me. I recommend merging that one > first, as I found it slightly easier to resolve the conflicts in that order. > > P.S. I expect to send another PMU related pull request of 3-4 fixes at some > point during the merge window. But they're all small and urgent (if we had a > few more weeks for 6.8, I'd have tried to squeeze them into 6.8). > > The following changes since commit 41bccc98fb7931d63d03f326a746ac4d429c1dd3: > > Linux 6.8-rc2 (2024-01-28 17:01:12 -0800) > > are available in the Git repository at: > > https://github.com/kvm-x86/linux.git tags/kvm-x86-pmu-6.9 > > for you to fetch changes up to 812d432373f629eb8d6cb696ea6804fca1534efa: > > KVM: x86/pmu: Explicitly check NMI from guest to reducee false positives (2024-02-26 15:57:22 -0800) Pulled, thanks. Paolo > ---------------------------------------------------------------- > KVM x86 PMU changes for 6.9: > > - Fix several bugs where KVM speciously prevents the guest from utilizing > fixed counters and architectural event encodings based on whether or not > guest CPUID reports support for the _architectural_ encoding. > > - Fix a variety of bugs in KVM's emulation of RDPMC, e.g. for "fast" reads, > priority of VMX interception vs #GP, PMC types in architectural PMUs, etc. > > - Add a selftest to verify KVM correctly emulates RDMPC, counter availability, > and a variety of other PMC-related behaviors that depend on guest CPUID, > i.e. are difficult to validate via KVM-Unit-Tests. > > - Zero out PMU metadata on AMD if the virtual PMU is disabled to avoid wasting > cycles, e.g. when checking if a PMC event needs to be synthesized when > skipping an instruction. > > - Optimize triggering of emulated events, e.g. for "count instructions" events > when skipping an instruction, which yields a ~10% performance improvement in > VM-Exit microbenchmarks when a vPMU is exposed to the guest. > > - Tighten the check for "PMI in guest" to reduce false positives if an NMI > arrives in the host while KVM is handling an IRQ VM-Exit. > > ---------------------------------------------------------------- > Dapeng Mi (1): > KVM: selftests: Test top-down slots event in x86's pmu_counters_test > > 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 > > Like Xu (1): > KVM: x86/pmu: Explicitly check NMI from guest to reducee false positives > > Sean Christopherson (32): > 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 > KVM: x86/pmu: Zero out PMU metadata on AMD if PMU is disabled > KVM: x86/pmu: Add common define to capture fixed counters offset > KVM: x86/pmu: Move pmc_idx => pmc translation helper to common code > KVM: x86/pmu: Snapshot and clear reprogramming bitmap before reprogramming > KVM: x86/pmu: Add macros to iterate over all PMCs given a bitmap > KVM: x86/pmu: Process only enabled PMCs when emulating events in software > KVM: x86/pmu: Snapshot event selectors that KVM emulates in software > KVM: x86/pmu: Expand the comment about what bits are check emulating events > KVM: x86/pmu: Check eventsel first when emulating (branch) insns retired > KVM: x86/pmu: Avoid CPL lookup if PMC enabline for USER and KERNEL is the same > > arch/x86/include/asm/kvm-x86-pmu-ops.h | 4 +- > arch/x86/include/asm/kvm_host.h | 11 +- > arch/x86/kvm/emulate.c | 2 +- > arch/x86/kvm/kvm_emulate.h | 2 +- > arch/x86/kvm/pmu.c | 163 ++++-- > arch/x86/kvm/pmu.h | 57 +- > arch/x86/kvm/svm/pmu.c | 22 +- > arch/x86/kvm/vmx/nested.c | 2 +- > arch/x86/kvm/vmx/pmu_intel.c | 222 +++----- > arch/x86/kvm/x86.c | 15 +- > arch/x86/kvm/x86.h | 6 - > tools/testing/selftests/kvm/Makefile | 2 + > .../testing/selftests/kvm/include/kvm_util_base.h | 4 + > tools/testing/selftests/kvm/include/x86_64/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/x86_64/pmu.c | 31 ++ > tools/testing/selftests/kvm/lib/x86_64/processor.c | 15 +- > .../selftests/kvm/x86_64/pmu_counters_test.c | 620 +++++++++++++++++++++ > .../selftests/kvm/x86_64/pmu_event_filter_test.c | 143 ++--- > .../kvm/x86_64/smaller_maxphyaddr_emulation_test.c | 2 +- > .../selftests/kvm/x86_64/userspace_msr_exit_test.c | 29 +- > .../selftests/kvm/x86_64/vmx_pmu_caps_test.c | 2 +- > 23 files changed, 1262 insertions(+), 399 deletions(-) > create mode 100644 tools/testing/selftests/kvm/include/x86_64/pmu.h > create mode 100644 tools/testing/selftests/kvm/lib/x86_64/pmu.c > create mode 100644 tools/testing/selftests/kvm/x86_64/pmu_counters_test.c >
Lots of PMU fixes and cleanups, along with related selftests. The most notable fix is to *not* disallow the use of fixed counters and event encodings just because the CPU doesn't report support for the matching architectural event encoding. Note, the selftests changes have several annoying conflicts with "the" selftests pull request that you'll also receive from me. I recommend merging that one first, as I found it slightly easier to resolve the conflicts in that order. P.S. I expect to send another PMU related pull request of 3-4 fixes at some point during the merge window. But they're all small and urgent (if we had a few more weeks for 6.8, I'd have tried to squeeze them into 6.8). The following changes since commit 41bccc98fb7931d63d03f326a746ac4d429c1dd3: Linux 6.8-rc2 (2024-01-28 17:01:12 -0800) are available in the Git repository at: https://github.com/kvm-x86/linux.git tags/kvm-x86-pmu-6.9 for you to fetch changes up to 812d432373f629eb8d6cb696ea6804fca1534efa: KVM: x86/pmu: Explicitly check NMI from guest to reducee false positives (2024-02-26 15:57:22 -0800) ---------------------------------------------------------------- KVM x86 PMU changes for 6.9: - Fix several bugs where KVM speciously prevents the guest from utilizing fixed counters and architectural event encodings based on whether or not guest CPUID reports support for the _architectural_ encoding. - Fix a variety of bugs in KVM's emulation of RDPMC, e.g. for "fast" reads, priority of VMX interception vs #GP, PMC types in architectural PMUs, etc. - Add a selftest to verify KVM correctly emulates RDMPC, counter availability, and a variety of other PMC-related behaviors that depend on guest CPUID, i.e. are difficult to validate via KVM-Unit-Tests. - Zero out PMU metadata on AMD if the virtual PMU is disabled to avoid wasting cycles, e.g. when checking if a PMC event needs to be synthesized when skipping an instruction. - Optimize triggering of emulated events, e.g. for "count instructions" events when skipping an instruction, which yields a ~10% performance improvement in VM-Exit microbenchmarks when a vPMU is exposed to the guest. - Tighten the check for "PMI in guest" to reduce false positives if an NMI arrives in the host while KVM is handling an IRQ VM-Exit. ---------------------------------------------------------------- Dapeng Mi (1): KVM: selftests: Test top-down slots event in x86's pmu_counters_test 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 Like Xu (1): KVM: x86/pmu: Explicitly check NMI from guest to reducee false positives Sean Christopherson (32): 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 KVM: x86/pmu: Zero out PMU metadata on AMD if PMU is disabled KVM: x86/pmu: Add common define to capture fixed counters offset KVM: x86/pmu: Move pmc_idx => pmc translation helper to common code KVM: x86/pmu: Snapshot and clear reprogramming bitmap before reprogramming KVM: x86/pmu: Add macros to iterate over all PMCs given a bitmap KVM: x86/pmu: Process only enabled PMCs when emulating events in software KVM: x86/pmu: Snapshot event selectors that KVM emulates in software KVM: x86/pmu: Expand the comment about what bits are check emulating events KVM: x86/pmu: Check eventsel first when emulating (branch) insns retired KVM: x86/pmu: Avoid CPL lookup if PMC enabline for USER and KERNEL is the same arch/x86/include/asm/kvm-x86-pmu-ops.h | 4 +- arch/x86/include/asm/kvm_host.h | 11 +- arch/x86/kvm/emulate.c | 2 +- arch/x86/kvm/kvm_emulate.h | 2 +- arch/x86/kvm/pmu.c | 163 ++++-- arch/x86/kvm/pmu.h | 57 +- arch/x86/kvm/svm/pmu.c | 22 +- arch/x86/kvm/vmx/nested.c | 2 +- arch/x86/kvm/vmx/pmu_intel.c | 222 +++----- arch/x86/kvm/x86.c | 15 +- arch/x86/kvm/x86.h | 6 - tools/testing/selftests/kvm/Makefile | 2 + .../testing/selftests/kvm/include/kvm_util_base.h | 4 + tools/testing/selftests/kvm/include/x86_64/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/x86_64/pmu.c | 31 ++ tools/testing/selftests/kvm/lib/x86_64/processor.c | 15 +- .../selftests/kvm/x86_64/pmu_counters_test.c | 620 +++++++++++++++++++++ .../selftests/kvm/x86_64/pmu_event_filter_test.c | 143 ++--- .../kvm/x86_64/smaller_maxphyaddr_emulation_test.c | 2 +- .../selftests/kvm/x86_64/userspace_msr_exit_test.c | 29 +- .../selftests/kvm/x86_64/vmx_pmu_caps_test.c | 2 +- 23 files changed, 1262 insertions(+), 399 deletions(-) create mode 100644 tools/testing/selftests/kvm/include/x86_64/pmu.h create mode 100644 tools/testing/selftests/kvm/lib/x86_64/pmu.c create mode 100644 tools/testing/selftests/kvm/x86_64/pmu_counters_test.c