On Mon, Apr 22, 2024 at 1:42 PM Shenlin Liang <liangshenlin@xxxxxxxxxxxxxxxxxx> wrote: > > '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. > > Cross compiling perf in X86 environment may encounter issues with missing > libraries and tools. Suggest compiling nativly in RISC-V environment > > 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) > > # ./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 > > Changes from v1->v2: > - Rebased on Linux 6.9-rc3. > > Changes from v2->v3: > - Add the missing assignment for 'vcpu_id_str' in patch 2. > - Remove parentheses that cause compilation errors > > 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 | 79 +++++++++++++++++++ > .../arch/riscv/util/riscv_exception_types.h | 35 ++++++++ > 6 files changed, 190 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 Queued this series for Linux-6.11 Thanks, Anup
