From: Zenghui Yu yuzenghui@huawei.com
euleros inclusion category: feature feature: perf kvm stat on arm64
picked from https://patchwork.kernel.org/patch/10989119/.
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'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 arm64.
We have a mapping between guest's "exit_code" and "exit_reason" which already exists under arch/arm64/include/asm/ (kvm_arm_exception_type), and we've used it to report guest's exit type through trace_kvm_exit(). Copy kvm_arm_exception_type into aarch64_guest_exits.h, thus export it to userspace.
It records on two available KVM tracepoints for arm64: "kvm:kvm_entry" and "kvm:kvm_exit", and reports statistical data which includes events handles time, samples, and so on.
A simple test go below:
# pgrep qemu 6039 9937
# ./tools/perf/perf kvm stat record -p 6039 [ perf record: Woken up 3 times to write data ] [ perf record: Captured and wrote 15.629 MB perf.data.guest (199063 samples) ]
# ./tools/perf/perf kvm stat report --event=vmexit
Analyze events for all VMs, all VCPUs:
VM-EXIT Samples Samples% Time% Min Time Max Time Avg time
TRAP 49040 97.15% 100.00% 2.60us 4072.98us 3431.60us ( +- 0.17% ) IRQ 1437 2.85% 0.00% 0.90us 24.56us 2.06us ( +- 1.37% )
Total Samples:50477, Total events handled time:168288630.04us.
Signed-off-by: Zenghui Yu yuzenghui@huawei.com Reviewed-by: Hailiang Zhang zhang.zhanghailiang@huawei.com Signed-off-by: Zenghui Yu yuzenghui@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- tools/perf/arch/arm64/Makefile | 2 + tools/perf/arch/arm64/util/Build | 1 + tools/perf/arch/arm64/util/aarch64_guest_exits.h | 27 ++++++++++++++ tools/perf/arch/arm64/util/kvm-stat.c | 47 ++++++++++++++++++++++++ 4 files changed, 77 insertions(+) create mode 100644 tools/perf/arch/arm64/util/aarch64_guest_exits.h create mode 100644 tools/perf/arch/arm64/util/kvm-stat.c
diff --git a/tools/perf/arch/arm64/Makefile b/tools/perf/arch/arm64/Makefile index dbef716..172146e 100644 --- a/tools/perf/arch/arm64/Makefile +++ b/tools/perf/arch/arm64/Makefile @@ -2,6 +2,8 @@ ifndef NO_DWARF PERF_HAVE_DWARF_REGS := 1 endif + +HAVE_KVM_STAT_SUPPORT := 1 PERF_HAVE_JITDUMP := 1 PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET := 1
diff --git a/tools/perf/arch/arm64/util/Build b/tools/perf/arch/arm64/util/Build index 9962187..393b989 100644 --- a/tools/perf/arch/arm64/util/Build +++ b/tools/perf/arch/arm64/util/Build @@ -1,6 +1,7 @@ libperf-y += header.o libperf-y += tsc.o libperf-y += sym-handling.o +libperf-y += kvm-stat.o libperf-$(CONFIG_DWARF) += dwarf-regs.o libperf-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind.o libperf-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o diff --git a/tools/perf/arch/arm64/util/aarch64_guest_exits.h b/tools/perf/arch/arm64/util/aarch64_guest_exits.h new file mode 100644 index 00000000..aec2e6e --- /dev/null +++ b/tools/perf/arch/arm64/util/aarch64_guest_exits.h @@ -0,0 +1,27 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright(c) 2019 Huawei Technologies Co., Ltd + */ + +#ifndef ARCH_PERF_AARCH64_GUEST_EXITS_H +#define ARCH_PERF_AARCH64_GUEST_EXITS_H + +/* virt.h */ +/* Error returned when an invalid stub number is passed into x0 */ +#define HVC_STUB_ERR 0xbadca11 + +/* kvm_asm.h */ +#define ARM_EXCEPTION_IRQ 0 +#define ARM_EXCEPTION_EL1_SERROR 1 +#define ARM_EXCEPTION_TRAP 2 +#define ARM_EXCEPTION_IL 3 +/* The hyp-stub will return this for any kvm_call_hyp() call */ +#define ARM_EXCEPTION_HYP_GONE HVC_STUB_ERR + +#define kvm_arm_exception_type \ + {ARM_EXCEPTION_IRQ, "IRQ" }, \ + {ARM_EXCEPTION_EL1_SERROR, "SERROR" }, \ + {ARM_EXCEPTION_TRAP, "TRAP" }, \ + {ARM_EXCEPTION_HYP_GONE, "HYP_GONE" } + +#endif /* ARCH_PERF_AARCH64_GUEST_EXITS_H */ diff --git a/tools/perf/arch/arm64/util/kvm-stat.c b/tools/perf/arch/arm64/util/kvm-stat.c new file mode 100644 index 00000000..b60b0ba --- /dev/null +++ b/tools/perf/arch/arm64/util/kvm-stat.c @@ -0,0 +1,47 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Arch specific functions for perf kvm stat. + * Copyright(c) 2019 Huawei Technologies Co., Ltd + */ +#include <errno.h> +#include "../../util/kvm-stat.h" +#include "../../util/evsel.h" +#include "aarch64_guest_exits.h" + +define_exit_reasons_table(arm64_exit_reasons, kvm_arm_exception_type); + +static struct kvm_events_ops exit_events = { + .is_begin_event = exit_event_begin, + .is_end_event = exit_event_end, + .decode_key = exit_event_decode_key, + .name = "VM-EXIT" +}; + +const char *vcpu_id_str = "vcpu_id"; +const int decode_str_len = 20; +const char *kvm_exit_reason = "ret"; +const char *kvm_entry_trace = "kvm:kvm_entry"; +const char *kvm_exit_trace = "kvm:kvm_exit"; + +const char *kvm_events_tp[] = { + "kvm:kvm_entry", + "kvm:kvm_exit", + NULL, +}; + +struct kvm_reg_events_ops kvm_reg_events_ops[] = { + { .name = "vmexit", .ops = &exit_events }, + { NULL, NULL }, +}; + +const char * const kvm_skip_events[] = { + NULL, +}; + +int cpu_isa_init(struct perf_kvm_stat *kvm, const char *cpuid __maybe_unused) +{ + kvm->exit_reasons = arm64_exit_reasons; + kvm->exit_reasons_isa = "aarch64"; + + return 0; +}