[PATCH v3 00/22] ARM64 PMU Partitioning

[Colton Lewis]

This series creates a new PMU scheme on ARM, a partitioned PMU that
allows reserving a subset of counters for more direct guest access,
significantly reducing overhead. More details, including performance
benchmarks, can be read in the v1 cover letter linked below.

v3:

* Return to using one kernel command line parameter for reserved host
  counters, but set the default value meaning no partitioning to -1 so
  0 isn't ambiguous. Adjust checks for partitioning accordingly.

* Move the function kvm_pmu_partition_supported() back out of the
  driver to avoid subbing has_vhe in 32-bit ARM code.

* Fix the kernel test robot build failures, one with KVM and no PMU,
  and one with PMU and no KVM.

* Scan entire series to remove vestigial changes and update comments.

v2:
https://lore.kernel.org/kvm/20250620221326.1261128-1-coltonlewis@google.com/

v1:
https://lore.kernel.org/kvm/20250602192702.2125115-1-coltonlewis@google.com/

Colton Lewis (21):
  arm64: cpufeature: Add cpucap for HPMN0
  arm64: Generate sign macro for sysreg Enums
  KVM: arm64: Define PMI{CNTR,FILTR}_EL0 as undef_access
  KVM: arm64: Reorganize PMU functions
  perf: arm_pmuv3: Introduce method to partition the PMU
  perf: arm_pmuv3: Generalize counter bitmasks
  perf: arm_pmuv3: Keep out of guest counter partition
  KVM: arm64: Correct kvm_arm_pmu_get_max_counters()
  KVM: arm64: Set up FGT for Partitioned PMU
  KVM: arm64: Writethrough trapped PMEVTYPER register
  KVM: arm64: Use physical PMSELR for PMXEVTYPER if partitioned
  KVM: arm64: Writethrough trapped PMOVS register
  KVM: arm64: Write fast path PMU register handlers
  KVM: arm64: Setup MDCR_EL2 to handle a partitioned PMU
  KVM: arm64: Account for partitioning in PMCR_EL0 access
  KVM: arm64: Context swap Partitioned PMU guest registers
  KVM: arm64: Enforce PMU event filter at vcpu_load()
  perf: arm_pmuv3: Handle IRQs for Partitioned PMU guest counters
  KVM: arm64: Inject recorded guest interrupts
  KVM: arm64: Add ioctl to partition the PMU when supported
  KVM: arm64: selftests: Add test case for partitioned PMU

Marc Zyngier (1):
  KVM: arm64: Cleanup PMU includes

 Documentation/virt/kvm/api.rst                |  21 +
 arch/arm/include/asm/arm_pmuv3.h              |  38 +
 arch/arm64/include/asm/arm_pmuv3.h            |  61 +-
 arch/arm64/include/asm/kvm_host.h             |  18 +-
 arch/arm64/include/asm/kvm_pmu.h              | 100 +++
 arch/arm64/kernel/cpufeature.c                |   8 +
 arch/arm64/kvm/Makefile                       |   2 +-
 arch/arm64/kvm/arm.c                          |  22 +
 arch/arm64/kvm/debug.c                        |  24 +-
 arch/arm64/kvm/hyp/include/hyp/switch.h       | 233 ++++++
 arch/arm64/kvm/pmu-emul.c                     | 674 +----------------
 arch/arm64/kvm/pmu-part.c                     | 378 ++++++++++
 arch/arm64/kvm/pmu.c                          | 702 ++++++++++++++++++
 arch/arm64/kvm/sys_regs.c                     |  79 +-
 arch/arm64/tools/cpucaps                      |   1 +
 arch/arm64/tools/gen-sysreg.awk               |   1 +
 arch/arm64/tools/sysreg                       |   6 +-
 drivers/perf/arm_pmuv3.c                      | 123 ++-
 include/linux/perf/arm_pmu.h                  |   6 +
 include/linux/perf/arm_pmuv3.h                |  14 +-
 include/uapi/linux/kvm.h                      |   4 +
 tools/include/uapi/linux/kvm.h                |   2 +
 .../selftests/kvm/arm64/vpmu_counter_access.c |  62 +-
 virt/kvm/kvm_main.c                           |   1 +
 24 files changed, 1828 insertions(+), 752 deletions(-)
 create mode 100644 arch/arm64/kvm/pmu-part.c


base-commit: 79150772457f4d45e38b842d786240c36bb1f97f
--
2.50.0.727.gbf7dc18ff4-goog