From: Zenghui Yu yuzenghui@huawei.com
virt inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I4IZPY CVE: NA
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When guest exits due to "TRAP", we can analyze the guest exit reasons deeplier. Enhance perf-kvm-stat to record and analyze VM TRAP events.
There is a mapping between guest's "trap_code" (ESR_ELx's bits[31:26]) and "trap_reason" - kvm_arm_exception_class. Copy it from kernel to aarch64_guest_exits.h, export it to userspace.
This patch records two new KVM tracepoints: "kvm:kvm_trap_enter" and "kvm:kvm_trap_exit", and reports statistical data between these two tracepoints.
A simple test go below:
# ./tools/perf/perf kvm stat record -p 20763 [ perf record: Woken up 92 times to write data ] [ perf record: Captured and wrote 203.727 MB perf.data.guest (2601786 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 640931 97.12% 100.00% 2.44us 14683.86us 3446.49us ( +- 0.05% ) IRQ 19019 2.88% 0.00% 0.90us 461.94us 2.12us ( +- 2.09% )
Total Samples:659950, Total events handled time:2209005391.30us.
# ./tools/perf/perf kvm stat report --event=trap
Analyze events for all VMs, all VCPUs:
TRAP-EVENT Samples Samples% Time% Min Time Max Time Avg time
WFx 601194 93.80% 99.98% 0.90us 4294.04us 3671.01us ( +- 0.03% ) SYS64 33714 5.26% 0.01% 1.10us 41.34us 5.68us ( +- 0.18% ) DABT_LOW 6014 0.94% 0.00% 1.12us 18.04us 2.57us ( +- 0.91% ) IABT_LOW 12 0.00% 0.01% 12597.76us 14679.96us 12893.61us ( +- 1.34% )
Total Samples:640934, Total events handled time:2207353434.56us.
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 Link: https://lore.kernel.org/r/1560330526-15468-6-git-send-email-yuzenghui@huawei... Link: https://gitee.com/openeuler/kernel/commit/59634497418b Reviewed-by: Yanan Wang wangyanan55@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- .../arch/arm64/util/aarch64_guest_exits.h | 72 +++++++++++++++++++ tools/perf/arch/arm64/util/kvm-stat.c | 68 ++++++++++++++++++ 2 files changed, 140 insertions(+)
diff --git a/tools/perf/arch/arm64/util/aarch64_guest_exits.h b/tools/perf/arch/arm64/util/aarch64_guest_exits.h index aec2e6e012d3..76e8f0358182 100644 --- a/tools/perf/arch/arm64/util/aarch64_guest_exits.h +++ b/tools/perf/arch/arm64/util/aarch64_guest_exits.h @@ -24,4 +24,76 @@ {ARM_EXCEPTION_TRAP, "TRAP" }, \ {ARM_EXCEPTION_HYP_GONE, "HYP_GONE" }
+/* esr.h */ +#define ESR_ELx_EC_UNKNOWN (0x00) +#define ESR_ELx_EC_WFx (0x01) +/* Unallocated EC: 0x02 */ +#define ESR_ELx_EC_CP15_32 (0x03) +#define ESR_ELx_EC_CP15_64 (0x04) +#define ESR_ELx_EC_CP14_MR (0x05) +#define ESR_ELx_EC_CP14_LS (0x06) +#define ESR_ELx_EC_FP_ASIMD (0x07) +#define ESR_ELx_EC_CP10_ID (0x08) /* EL2 only */ +#define ESR_ELx_EC_PAC (0x09) /* EL2 and above */ +/* Unallocated EC: 0x0A - 0x0B */ +#define ESR_ELx_EC_CP14_64 (0x0C) +#define ESR_ELx_EC_BTI (0x0D) +#define ESR_ELx_EC_ILL (0x0E) +/* Unallocated EC: 0x0F - 0x10 */ +#define ESR_ELx_EC_SVC32 (0x11) +#define ESR_ELx_EC_HVC32 (0x12) /* EL2 only */ +#define ESR_ELx_EC_SMC32 (0x13) /* EL2 and above */ +/* Unallocated EC: 0x14 */ +#define ESR_ELx_EC_SVC64 (0x15) +#define ESR_ELx_EC_HVC64 (0x16) /* EL2 and above */ +#define ESR_ELx_EC_SMC64 (0x17) /* EL2 and above */ +#define ESR_ELx_EC_SYS64 (0x18) +#define ESR_ELx_EC_SVE (0x19) +#define ESR_ELx_EC_ERET (0x1a) /* EL2 only */ +/* Unallocated EC: 0x1B */ +#define ESR_ELx_EC_FPAC (0x1C) /* EL1 and above */ +/* Unallocated EC: 0x1D - 0x1E */ +#define ESR_ELx_EC_IMP_DEF (0x1f) /* EL3 only */ +#define ESR_ELx_EC_IABT_LOW (0x20) +#define ESR_ELx_EC_IABT_CUR (0x21) +#define ESR_ELx_EC_PC_ALIGN (0x22) +/* Unallocated EC: 0x23 */ +#define ESR_ELx_EC_DABT_LOW (0x24) +#define ESR_ELx_EC_DABT_CUR (0x25) +#define ESR_ELx_EC_SP_ALIGN (0x26) +/* Unallocated EC: 0x27 */ +#define ESR_ELx_EC_FP_EXC32 (0x28) +/* Unallocated EC: 0x29 - 0x2B */ +#define ESR_ELx_EC_FP_EXC64 (0x2C) +/* Unallocated EC: 0x2D - 0x2E */ +#define ESR_ELx_EC_SERROR (0x2F) +#define ESR_ELx_EC_BREAKPT_LOW (0x30) +#define ESR_ELx_EC_BREAKPT_CUR (0x31) +#define ESR_ELx_EC_SOFTSTP_LOW (0x32) +#define ESR_ELx_EC_SOFTSTP_CUR (0x33) +#define ESR_ELx_EC_WATCHPT_LOW (0x34) +#define ESR_ELx_EC_WATCHPT_CUR (0x35) +/* Unallocated EC: 0x36 - 0x37 */ +#define ESR_ELx_EC_BKPT32 (0x38) +/* Unallocated EC: 0x39 */ +#define ESR_ELx_EC_VECTOR32 (0x3A) /* EL2 only */ +/* Unallocated EC: 0x3B */ +#define ESR_ELx_EC_BRK64 (0x3C) +/* Unallocated EC: 0x3D - 0x3F */ +#define ESR_ELx_EC_MAX (0x3F) + +/* kvm_arm.h */ +#define ECN(x) { ESR_ELx_EC_##x, #x } + +#define kvm_arm_exception_class \ + ECN(UNKNOWN), ECN(WFx), ECN(CP15_32), ECN(CP15_64), ECN(CP14_MR), \ + ECN(CP14_LS), ECN(FP_ASIMD), ECN(CP10_ID), ECN(PAC), ECN(CP14_64), \ + ECN(SVC64), ECN(HVC64), ECN(SMC64), ECN(SYS64), ECN(SVE), \ + ECN(IMP_DEF), ECN(IABT_LOW), ECN(IABT_CUR), \ + ECN(PC_ALIGN), ECN(DABT_LOW), ECN(DABT_CUR), \ + ECN(SP_ALIGN), ECN(FP_EXC32), ECN(FP_EXC64), ECN(SERROR), \ + ECN(BREAKPT_LOW), ECN(BREAKPT_CUR), ECN(SOFTSTP_LOW), \ + ECN(SOFTSTP_CUR), ECN(WATCHPT_LOW), ECN(WATCHPT_CUR), \ + ECN(BKPT32), ECN(VECTOR32), ECN(BRK64) + #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 index 2fed20370829..a0a97073d2d1 100644 --- a/tools/perf/arch/arm64/util/kvm-stat.c +++ b/tools/perf/arch/arm64/util/kvm-stat.c @@ -4,10 +4,14 @@ * Copyright(c) 2019 Huawei Technologies Co., Ltd */
+#include <string.h> +#include "../../../util/debug.h" +#include "../../../util/evsel.h" #include "../../../util/kvm-stat.h" #include "aarch64_guest_exits.h"
define_exit_reasons_table(arm64_exit_reasons, kvm_arm_exception_type); +define_exit_reasons_table(arm64_trap_reasons, kvm_arm_exception_class);
static struct kvm_events_ops exit_events = { .is_begin_event = exit_event_begin, @@ -22,14 +26,78 @@ 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_trap_reason = "esr_ec"; +const char *kvm_trap_enter_trace = "kvm:kvm_trap_enter"; +const char *kvm_trap_exit_trace = "kvm:kvm_trap_exit"; + +static void trap_event_get_key(struct evsel *evsel, + struct perf_sample *sample, + struct event_key *key) +{ + key->info = 0; + key->key = evsel__intval(evsel, sample, kvm_trap_reason); +} + +static const char *get_trap_reason(u64 exit_code) +{ + struct exit_reasons_table *tbl = arm64_trap_reasons; + + while (tbl->reason != NULL) { + if (tbl->exit_code == exit_code) + return tbl->reason; + tbl++; + } + + pr_err("Unknown kvm trap exit code: %lld on aarch64\n", + (unsigned long long)exit_code); + return "UNKNOWN"; +} + +static bool trap_event_end(struct evsel *evsel, + struct perf_sample *sample __maybe_unused, + struct event_key *key __maybe_unused) +{ + return (!strcmp(evsel->name, kvm_trap_exit_trace)); +} + +static bool trap_event_begin(struct evsel *evsel, + struct perf_sample *sample, struct event_key *key) +{ + if (!strcmp(evsel->name, kvm_trap_enter_trace)) { + trap_event_get_key(evsel, sample, key); + return true; + } + + return false; +} + +static void trap_event_decode_key(struct perf_kvm_stat *kvm __maybe_unused, + struct event_key *key, + char *decode) +{ + const char *trap_reason = get_trap_reason(key->key); + + scnprintf(decode, decode_str_len, "%s", trap_reason); +} + +static struct kvm_events_ops trap_events = { + .is_begin_event = trap_event_begin, + .is_end_event = trap_event_end, + .decode_key = trap_event_decode_key, + .name = "TRAP-EVENT", +}; + const char *kvm_events_tp[] = { "kvm:kvm_entry", "kvm:kvm_exit", + "kvm:kvm_trap_enter", + "kvm:kvm_trap_exit", NULL, };
struct kvm_reg_events_ops kvm_reg_events_ops[] = { { .name = "vmexit", .ops = &exit_events }, + { .name = "trap", .ops = &trap_events }, { NULL, NULL }, };