kernel/tools/testing/selftests/kvm/include/x86/pmu.h, branch linux-rolling-stable

KVM: selftests: Handle Intel Atom errata that leads to PMU event overcount

2025-09-23T15:38:59Z

Add a PMU errata framework and use it to relax precise event counts on Atom platforms that overcount "Instruction Retired" and "Branch Instruction Retired" events, as the overcount issues on VM-Exit/VM-Entry are impossible to prevent from userspace, e.g. the test can't prevent host IRQs. Setup errata during early initialization and automatically sync the mask to VMs so that tests can check for errata without having to manually manage host=>guest variables. For Intel Atom CPUs, the PMU events "Instruction Retired" or "Branch Instruction Retired" may be overcounted for some certain instructions, like FAR CALL/JMP, RETF, IRET, VMENTRY/VMEXIT/VMPTRLD and complex SGX/SMX/CSTATE instructions/flows. The detailed information can be found in the errata (section SRF7): https://edc.intel.com/content/www/us/en/design/products-and-solutions/processors-and-chipsets/sierra-forest/xeon-6700-series-processor-with-e-cores-specification-update/errata-details/ For the Atom platforms before Sierra Forest (including Sierra Forest), Both 2 events "Instruction Retired" and "Branch Instruction Retired" would be overcounted on these certain instructions, but for Clearwater Forest only "Instruction Retired" event is overcounted on these instructions. Signed-off-by: dongsheng Co-developed-by: Dapeng Mi Signed-off-by: Dapeng Mi Tested-by: Yi Lai Co-developed-by: Sean Christopherson Reviewed-by: Dapeng Mi Tested-by: Dapeng Mi Link: https://lore.kernel.org/r/20250919214648.1585683-6-seanjc@google.com Signed-off-by: Sean Christopherson

KVM: selftests: Validate more arch-events in pmu_counters_test

2025-09-23T15:38:59Z

Add support for 5 new architectural events (4 topdown level 1 metrics events and LBR inserts event) that will first show up in Intel's Clearwater Forest CPUs. Detailed info about the new events can be found in SDM section 21.2.7 "Pre-defined Architectural Performance Events". Signed-off-by: Dapeng Mi Tested-by: Yi Lai [sean: drop "unavailable_mask" changes] Tested-by: Dapeng Mi Link: https://lore.kernel.org/r/20250919214648.1585683-5-seanjc@google.com Signed-off-by: Sean Christopherson

KVM: selftests: Use canonical $(ARCH) paths for KVM selftests directories

2024-12-18T22:15:04Z

Use the kernel's canonical $(ARCH) paths instead of the raw target triple for KVM selftests directories. KVM selftests are quite nearly the only place in the entire kernel that using the target triple for directories, tools/testing/selftests/drivers/s390x being the lone holdout. Using the kernel's preferred nomenclature eliminates the minor, but annoying, friction of having to translate to KVM's selftests directories, e.g. for pattern matching, opening files, running selftests, etc. Opportunsitically delete file comments that reference the full path of the file, as they are obviously prone to becoming stale, and serve no known purpose. Reviewed-by: Muhammad Usama Anjum Acked-by: Claudio Imbrenda Acked-by: Andrew Jones Link: https://lore.kernel.org/r/20241128005547.4077116-16-seanjc@google.com Signed-off-by: Sean Christopherson