[PATCH v3 00/22] ARM64 PMU Partitioning

Colton Lewis
2025-06-26T20:05:51Z

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