| Message ID | 20220127162033.54290-1-alexandru.elisei@arm.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | arm64: Improve PMU support on heterogeneous systems | expand |
Hi, The KVM patches were picked up, I'm hoping they land in v5.18-rc1. I'll send a new version of the kvmtool series when that happens. I would really appreciate some sort of review before the next iteration. Thanks, Alex On Thu, Jan 27, 2022 at 04:20:23PM +0000, Alexandru Elisei wrote: > The series can be found at [1], and the Linux patches that this series is > based on at [2]. > > The series adds support for the KVM_ARM_VCPU_PMU_V3_SET_PMU PMU attribute, > which allows userspace to set a PMU for a VCPU. This PMU is used by KVM > when creating perf events to emulate the guest PMU. > > Without settings this attribute, the PMU used when creating events is the > first one that successfully probed when booting, but this is unreliable as > the probe order can change (if the order of the PMUs is changed in the DTB > or if asynchronous driver probing is enabled on the host's command line), > and furthermore it requires the user to have intimate knowledge of how the > PMU was chosen in order to pin the VM on the correct physical CPUs. > > With KVM_ARM_VCPU_PMU_V3_SET_PMU, the user is still expected to pin the > VCPUs on a particular set of CPUs, but now it can be any CPUs as long as > they share the same PMU. The set does not depend anymore on the driver > probe order and all that is necessary for the user to know is which CPUs > are the little core and which are the big cores, in a big.little > configuration, which I believe is more reasonable. > > Patches #1-#2 are fixes and can be taken independently of this series. > > Patches #3-#6 move the PMU code to aarch64, where it belongs, because the > PMU has never been supported on KVM for arm. This also paves the way for > pulling in the KVM_ARM_VCPU_PMU_V3_SET_PMU attribute, which was not defined > for KVM for arm (when KVM supported arm). This also can be merged right > now, independently of the other patches. > > Patch #7 adds the cpumask_* functions which are necessary for subsequent > patches. > > Patch #9 adds basic support for KVM_ARM_VCPU_PMU_V3_SET_PMU; the user is > still expected to use taskset to pin the entire VM to the correct CPUs. > > Patch #10 adds --vcpu-affinity command line argument to pin VCPUs to the > correct CPUs without pinning the rest of the kvmtool threads. > > Changes since v1: > > * Patch #2 ("bitops.h: Include wordsize.h to provide the __WORDSIZE > define") is new. > > * Added for_each_cpu(), cpumask_and() and cpumask_subset() functions and > all the cpumask_* functions are added in one patch. > > * Bumped NR_CPUS fro arm64 to 4096 to match the Linux Kconfig option. > > * Reworked the way kvmtool specific header files were included to use > quotes to clearly differentiate them from the system level headers and to > keep the style consistent with the current code (for example, #include > <linux/bitops.h> is now "linux/bitops.h"). > > * Patch #10 ("arm64: Add --vcpu-affinity command line argument") is new. > > [1] https://gitlab.arm.com/linux-arm/kvmtool-ae/-/tree/pmu-big-little-fix-v2 > [2] https://gitlab.arm.com/linux-arm/linux-ae/-/tree/pmu-big-little-fix-v4 > > Alexandru Elisei (10): > linux/err.h: Add missing stdbool.h include > bitops.h: Include wordsize.h to provide the __WORDSIZE define > arm: Move arch specific VCPU features to the arch specific function > arm: Get rid of the ARM_VCPU_FEATURE_FLAGS() macro > arm: Make the PMUv3 emulation code arm64 specific > arm64: Rework set_pmu_attr() > Add cpumask functions > update_headers.sh: Sync headers with Linux v5.17-rc1 + SET_PMU > attribute > arm64: Add support for KVM_ARM_VCPU_PMU_V3_SET_PMU > arm64: Add --vcpu-affinity command line argument > > Makefile | 6 +- > arm/aarch32/include/asm/kernel.h | 8 + > arm/aarch32/include/kvm/kvm-cpu-arch.h | 4 - > arm/aarch64/arm-cpu.c | 3 +- > arm/aarch64/include/asm/kernel.h | 8 + > arm/aarch64/include/asm/kvm.h | 4 + > .../arm-common => aarch64/include/asm}/pmu.h | 0 > arm/aarch64/include/kvm/kvm-config-arch.h | 5 + > arm/aarch64/include/kvm/kvm-cpu-arch.h | 6 - > arm/aarch64/kvm-cpu.c | 21 ++ > arm/aarch64/kvm.c | 32 +++ > arm/aarch64/pmu.c | 231 ++++++++++++++++ > arm/include/arm-common/kvm-arch.h | 7 + > arm/include/arm-common/kvm-config-arch.h | 1 + > arm/kvm-cpu.c | 14 +- > arm/pmu.c | 76 ------ > include/linux/bitmap.h | 71 +++++ > include/linux/bitops.h | 4 + > include/linux/bits.h | 8 + > include/linux/cpumask.h | 67 +++++ > include/linux/err.h | 2 + > include/linux/find.h | 30 ++ > include/linux/kernel.h | 6 + > include/linux/kvm.h | 16 ++ > mips/include/asm/kernel.h | 8 + > powerpc/include/asm/kernel.h | 8 + > util/bitmap.c | 256 ++++++++++++++++++ > util/find.c | 40 +++ > x86/include/asm/kernel.h | 8 + > x86/include/asm/kvm.h | 16 +- > 30 files changed, 867 insertions(+), 99 deletions(-) > create mode 100644 arm/aarch32/include/asm/kernel.h > create mode 100644 arm/aarch64/include/asm/kernel.h > rename arm/{include/arm-common => aarch64/include/asm}/pmu.h (100%) > create mode 100644 arm/aarch64/pmu.c > delete mode 100644 arm/pmu.c > create mode 100644 include/linux/bitmap.h > create mode 100644 include/linux/bits.h > create mode 100644 include/linux/cpumask.h > create mode 100644 include/linux/find.h > create mode 100644 mips/include/asm/kernel.h > create mode 100644 powerpc/include/asm/kernel.h > create mode 100644 util/bitmap.c > create mode 100644 util/find.c > create mode 100644 x86/include/asm/kernel.h > > -- > 2.31.1 > > _______________________________________________ > kvmarm mailing list > kvmarm@lists.cs.columbia.edu > https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
The series can be found at [1], and the Linux patches that this series is based on at [2]. The series adds support for the KVM_ARM_VCPU_PMU_V3_SET_PMU PMU attribute, which allows userspace to set a PMU for a VCPU. This PMU is used by KVM when creating perf events to emulate the guest PMU. Without settings this attribute, the PMU used when creating events is the first one that successfully probed when booting, but this is unreliable as the probe order can change (if the order of the PMUs is changed in the DTB or if asynchronous driver probing is enabled on the host's command line), and furthermore it requires the user to have intimate knowledge of how the PMU was chosen in order to pin the VM on the correct physical CPUs. With KVM_ARM_VCPU_PMU_V3_SET_PMU, the user is still expected to pin the VCPUs on a particular set of CPUs, but now it can be any CPUs as long as they share the same PMU. The set does not depend anymore on the driver probe order and all that is necessary for the user to know is which CPUs are the little core and which are the big cores, in a big.little configuration, which I believe is more reasonable. Patches #1-#2 are fixes and can be taken independently of this series. Patches #3-#6 move the PMU code to aarch64, where it belongs, because the PMU has never been supported on KVM for arm. This also paves the way for pulling in the KVM_ARM_VCPU_PMU_V3_SET_PMU attribute, which was not defined for KVM for arm (when KVM supported arm). This also can be merged right now, independently of the other patches. Patch #7 adds the cpumask_* functions which are necessary for subsequent patches. Patch #9 adds basic support for KVM_ARM_VCPU_PMU_V3_SET_PMU; the user is still expected to use taskset to pin the entire VM to the correct CPUs. Patch #10 adds --vcpu-affinity command line argument to pin VCPUs to the correct CPUs without pinning the rest of the kvmtool threads. Changes since v1: * Patch #2 ("bitops.h: Include wordsize.h to provide the __WORDSIZE define") is new. * Added for_each_cpu(), cpumask_and() and cpumask_subset() functions and all the cpumask_* functions are added in one patch. * Bumped NR_CPUS fro arm64 to 4096 to match the Linux Kconfig option. * Reworked the way kvmtool specific header files were included to use quotes to clearly differentiate them from the system level headers and to keep the style consistent with the current code (for example, #include <linux/bitops.h> is now "linux/bitops.h"). * Patch #10 ("arm64: Add --vcpu-affinity command line argument") is new. [1] https://gitlab.arm.com/linux-arm/kvmtool-ae/-/tree/pmu-big-little-fix-v2 [2] https://gitlab.arm.com/linux-arm/linux-ae/-/tree/pmu-big-little-fix-v4 Alexandru Elisei (10): linux/err.h: Add missing stdbool.h include bitops.h: Include wordsize.h to provide the __WORDSIZE define arm: Move arch specific VCPU features to the arch specific function arm: Get rid of the ARM_VCPU_FEATURE_FLAGS() macro arm: Make the PMUv3 emulation code arm64 specific arm64: Rework set_pmu_attr() Add cpumask functions update_headers.sh: Sync headers with Linux v5.17-rc1 + SET_PMU attribute arm64: Add support for KVM_ARM_VCPU_PMU_V3_SET_PMU arm64: Add --vcpu-affinity command line argument Makefile | 6 +- arm/aarch32/include/asm/kernel.h | 8 + arm/aarch32/include/kvm/kvm-cpu-arch.h | 4 - arm/aarch64/arm-cpu.c | 3 +- arm/aarch64/include/asm/kernel.h | 8 + arm/aarch64/include/asm/kvm.h | 4 + .../arm-common => aarch64/include/asm}/pmu.h | 0 arm/aarch64/include/kvm/kvm-config-arch.h | 5 + arm/aarch64/include/kvm/kvm-cpu-arch.h | 6 - arm/aarch64/kvm-cpu.c | 21 ++ arm/aarch64/kvm.c | 32 +++ arm/aarch64/pmu.c | 231 ++++++++++++++++ arm/include/arm-common/kvm-arch.h | 7 + arm/include/arm-common/kvm-config-arch.h | 1 + arm/kvm-cpu.c | 14 +- arm/pmu.c | 76 ------ include/linux/bitmap.h | 71 +++++ include/linux/bitops.h | 4 + include/linux/bits.h | 8 + include/linux/cpumask.h | 67 +++++ include/linux/err.h | 2 + include/linux/find.h | 30 ++ include/linux/kernel.h | 6 + include/linux/kvm.h | 16 ++ mips/include/asm/kernel.h | 8 + powerpc/include/asm/kernel.h | 8 + util/bitmap.c | 256 ++++++++++++++++++ util/find.c | 40 +++ x86/include/asm/kernel.h | 8 + x86/include/asm/kvm.h | 16 +- 30 files changed, 867 insertions(+), 99 deletions(-) create mode 100644 arm/aarch32/include/asm/kernel.h create mode 100644 arm/aarch64/include/asm/kernel.h rename arm/{include/arm-common => aarch64/include/asm}/pmu.h (100%) create mode 100644 arm/aarch64/pmu.c delete mode 100644 arm/pmu.c create mode 100644 include/linux/bitmap.h create mode 100644 include/linux/bits.h create mode 100644 include/linux/cpumask.h create mode 100644 include/linux/find.h create mode 100644 mips/include/asm/kernel.h create mode 100644 powerpc/include/asm/kernel.h create mode 100644 util/bitmap.c create mode 100644 util/find.c create mode 100644 x86/include/asm/kernel.h