Give feature MSRs that same treatment as CPUID and disallow changing said MSRs after KVM_RUN. Fix a tangentially related bug in the vPMU where KVM leaves the vLBRs enabled after userspace disables the guest's entire vPMU. The bulk of this series is a rework of the vmx_pmu_caps_test, a.k.a. the PERF_CAPABILITIES selftests, to expand its coverage. In addition to verifying that KVM rejects changes after KVM_RUN, verify other bits beyond full-width writes and the LBR format. Note! There is a sneaky, small, but massive change buried halfway through this series that will affect all x86 selftests. Patch Verify KVM preserves userspace writes to "durable" MSRs adds a KVM_GET_MSRS after every KVM_SET_MSRS that writes a single MSR and expects to succeeded. The intent is to opportunistically verify that KVM provides "read what you wrote" for all "durable" MSRs. The PERF_CAPS test was manually verifying this behavior, and while it seems kinda gratuitous, the coverage is quite cheap from both a performance and maintenance cost, i.e. I can't think of a reason _not_ to do it. v3: - Collect reviews. [Xiaoyao] - Fix the PMU selftests _before_ introducing the breaking KVM change. [Like] - Actually use kvm_vcpu_has_run()... [Yu] v2: https://lore.kernel.org/all/20230210003148.2646712-1-seanjc@xxxxxxxxxx v1: https://lore.kernel.org/all/20220805172945.35412-1-seanjc@xxxxxxxxxx Sean Christopherson (21): KVM: x86: Rename kvm_init_msr_list() to clarify it inits multiple lists KVM: x86: Add a helper to query whether or not a vCPU has ever run KVM: x86: Add macros to track first...last VMX feature MSRs KVM: x86: Generate set of VMX feature MSRs using first/last definitions KVM: selftests: Split PMU caps sub-tests to avoid writing MSR after KVM_RUN KVM: x86: Disallow writes to immutable feature MSRs after KVM_RUN KVM: x86/pmu: WARN and bug the VM if PMU is refreshed after vCPU has run KVM: x86/pmu: Zero out LBR capabilities during PMU refresh KVM: selftests: Move 0/initial value PERF_CAPS checks to dedicated sub-test KVM: selftests: Assert that full-width PMC writes are supported if PDCM=1 KVM: selftests: Print out failing MSR and value in vcpu_set_msr() KVM: selftests: Verify KVM preserves userspace writes to "durable" MSRs KVM: selftests: Drop now-redundant checks on PERF_CAPABILITIES writes KVM: selftests: Test all fungible features in PERF_CAPABILITIES KVM: selftests: Test all immutable non-format bits in PERF_CAPABILITIES KVM: selftests: Expand negative testing of guest writes to PERF_CAPABILITIES KVM: selftests: Test post-KVM_RUN writes to PERF_CAPABILITIES KVM: selftests: Drop "all done!" printf() from PERF_CAPABILITIES test KVM: selftests: Refactor LBR_FMT test to avoid use of separate macro KVM: selftests: Add negative testcase for PEBS format in PERF_CAPABILITIES KVM: selftests: Verify LBRs are disabled if vPMU is disabled arch/x86/kvm/cpuid.c | 2 +- arch/x86/kvm/mmu/mmu.c | 2 +- arch/x86/kvm/pmu.c | 3 + arch/x86/kvm/svm/svm.c | 2 +- arch/x86/kvm/vmx/pmu_intel.c | 10 + arch/x86/kvm/vmx/vmx.c | 8 +- arch/x86/kvm/x86.c | 102 ++++--- arch/x86/kvm/x86.h | 13 + .../selftests/kvm/include/x86_64/processor.h | 41 ++- .../selftests/kvm/x86_64/vmx_pmu_caps_test.c | 248 ++++++++++++++---- 10 files changed, 341 insertions(+), 90 deletions(-) base-commit: 45dd9bc75d9adc9483f0c7d662ba6e73ed698a0b -- 2.40.0.rc1.284.g88254d51c5-goog
