On 4/14/24 20:11, Shenlin Liang wrote:
Changes from v1->v2: - Rebased on Linux 6.9-rc3. 'perf kvm stat report/record' generates a statistical analysis of KVM events and can be used to analyze guest exit reasons. This patch tries to add stat support on riscv. Map the return value of trace_kvm_exit() to the specific cause of the exception, and export it to userspace. It records on two available KVM tracepoints for riscv: "kvm:kvm_entry" and "kvm:kvm_exit", and reports statistical data which includes events handles time, samples, and so on. Simple tests go below: # ./perf kvm record -e "kvm:kvm_entry" -e "kvm:kvm_exit" Lowering default frequency rate from 4000 to 2500. Please consider tweaking /proc/sys/kernel/perf_event_max_sample_rate. [ perf record: Woken up 18 times to write data ] [ perf record: Captured and wrote 5.433 MB perf.data.guest (62519 samples)
I want to test these patches but couldn't build a perf for RISC-V with libtraceevent enabled. It fails with pkg-config dependencies when I tried to build it (both via buildroot and directly from kernel source).
# ./perf kvm report 31K kvm:kvm_entry 31K kvm:kvm_exit # ./perf kvm stat record -a [ perf record: Woken up 3 times to write data ] [ perf record: Captured and wrote 8.502 MB perf.data.guest (99338 samples) ] # ./perf kvm stat report --event=vmexit Event name Samples Sample% Time (ns) Time% Max Time (ns) Min Time (ns) Mean Time (ns) STORE_GUEST_PAGE_FAULT 26968 54.00% 2003031800 40.00% 3361400 27600 74274 LOAD_GUEST_PAGE_FAULT 17645 35.00% 1153338100 23.00% 2513400 30800 65363 VIRTUAL_INST_FAULT 1247 2.00% 340820800 6.00% 1190800 43300 273312 INST_GUEST_PAGE_FAULT 1128 2.00% 340645800 6.00% 2123200 30200 301990 SUPERVISOR_SYSCALL 1019 2.00% 245989900 4.00% 1851500 29300 241403 LOAD_ACCESS 986 1.00% 671556200 13.00% 4180200 100700 681091 INST_ACCESS 655 1.00% 170054800 3.00% 1808300 54600 259625 HYPERVISOR_SYSCALL 21 0.00% 4276400 0.00% 716500 116000 203638 Shenlin Liang (2): RISCV: KVM: add tracepoints for entry and exit events perf kvm/riscv: Port perf kvm stat to RISC-V arch/riscv/kvm/trace.h | 67 ++++++++++++++++ arch/riscv/kvm/vcpu.c | 7 ++ tools/perf/arch/riscv/Makefile | 1 + tools/perf/arch/riscv/util/Build | 1 + tools/perf/arch/riscv/util/kvm-stat.c | 78 +++++++++++++++++++ .../arch/riscv/util/riscv_exception_types.h | 41 ++++++++++ 6 files changed, 195 insertions(+) create mode 100644 arch/riscv/kvm/trace.h create mode 100644 tools/perf/arch/riscv/util/kvm-stat.c create mode 100644 tools/perf/arch/riscv/util/riscv_exception_types.h
