Re: [PATCH v2] perf kvm: Add kvm-stat for loongarch64
From: maobibo
Date: Sun Apr 07 2024 - 22:01:42 EST
On 2024/4/8 上午3:08, Ian Rogers wrote:
On Sun, Apr 7, 2024 at 1:37 AM Bibo Mao <maobibo@xxxxxxxxxxx> wrote:
Add support for 'perf kvm stat' on loongarch64 platform, now only
kvm exit event is supported.
Here is example output about "perf kvm --host stat report" command
Event name Samples Sample% Time (ns) Time% Mean Time (ns)
Mem store 83969 51.00% 625697070 8.00% 7451
Mem read 37641 22.00% 112485730 1.00% 2988
Interrupt 15542 9.00% 20620190 0.00% 1326
Iocsr 15207 9.00% 94296190 1.00% 6200
Hypercall 4873 2.00% 12265280 0.00% 2516
Idle 3713 2.00% 6322055860 87.00% 1702681
FPU 1819 1.00% 2750300 0.00% 1511
Ifecth 502 0.00% 1341740 0.00% 2672
Mem modify 324 0.00% 602240 0.00% 1858
Cpucfg 55 0.00% 77610 0.00% 1411
Csr 12 0.00% 19690 0.00% 1640
LASX 3 0.00% 4870 0.00% 1623
LSX 2 0.00% 2100 0.00% 1050
Signed-off-by: Bibo Mao <maobibo@xxxxxxxxxxx>
v1 --- v2:
1. Add child_ops for kvm exit event, split kvm:kvm_exit_gspr events
into cpucfg/csr/iocsr/idle child events by decoding detailed gspr
instruction.
2. Remove some exception code type which does not happen in current
kvm implementation, such as meomry NR/NX/priviledge exception.
---
tools/perf/arch/loongarch/Makefile | 1 +
tools/perf/arch/loongarch/util/Build | 2 +
tools/perf/arch/loongarch/util/header.c | 85 +++++++++++++
tools/perf/arch/loongarch/util/kvm-stat.c | 141 ++++++++++++++++++++++
4 files changed, 229 insertions(+)
create mode 100644 tools/perf/arch/loongarch/util/header.c
create mode 100644 tools/perf/arch/loongarch/util/kvm-stat.c
diff --git a/tools/perf/arch/loongarch/Makefile b/tools/perf/arch/loongarch/Makefile
index 3992a67a87d9..c89d6bb6b184 100644
--- a/tools/perf/arch/loongarch/Makefile
+++ b/tools/perf/arch/loongarch/Makefile
@@ -4,6 +4,7 @@ PERF_HAVE_DWARF_REGS := 1
endif
PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET := 1
PERF_HAVE_JITDUMP := 1
+HAVE_KVM_STAT_SUPPORT := 1
#
# Syscall table generation for perf
diff --git a/tools/perf/arch/loongarch/util/Build b/tools/perf/arch/loongarch/util/Build
index d776125a2d06..e1a13761037b 100644
--- a/tools/perf/arch/loongarch/util/Build
+++ b/tools/perf/arch/loongarch/util/Build
@@ -1,5 +1,7 @@
perf-y += perf_regs.o
+perf-y += header.o
+perf-$(CONFIG_LIBTRACEEVENT) += kvm-stat.o
perf-$(CONFIG_DWARF) += dwarf-regs.o
perf-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind.o
perf-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
diff --git a/tools/perf/arch/loongarch/util/header.c b/tools/perf/arch/loongarch/util/header.c
new file mode 100644
index 000000000000..8f7061cf6977
--- /dev/null
+++ b/tools/perf/arch/loongarch/util/header.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Implementation of get_cpuid().
+ *
+ * Author: Nikita Shubin <n.shubin@xxxxxxxxx>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <api/fs/fs.h>
+#include <errno.h>
+#include "util/debug.h"
+#include "util/header.h"
+
+#define CPUINFO_MODEL "Model Name"
+#define CPUINFO "/proc/cpuinfo"
+
+static char *_get_field(const char *line)
+{
+ char *line2, *nl;
+
+ line2 = strrchr(line, ' ');
+ if (!line2)
+ return NULL;
+
+ line2++;
+ nl = strrchr(line, '\n');
+ if (!nl)
+ return NULL;
+
+ return strndup(line2, nl - line2);
+}
+
+static char *_get_cpuid(void)
+{
+ char *line = NULL;
+ char *model = NULL;
+ char *cpuid = NULL;
+ int read;
+ unsigned long line_sz;
+ FILE *cpuinfo;
+
+ cpuinfo = fopen(CPUINFO, "r");
+ if (cpuinfo == NULL)
+ return cpuid;
+
+ while ((read = getline(&line, &line_sz, cpuinfo)) != -1) {
+ if (strncmp(line, CPUINFO_MODEL, strlen(CPUINFO_MODEL)))
+ continue;
+
+ model = _get_field(line);
+ if (!model)
+ goto free;
+ break;
+ }
+
+ if (asprintf(&cpuid, "%s", model) < 0)
+ cpuid = NULL;
+
+free:
+ fclose(cpuinfo);
+ free(model);
+ return cpuid;
+}
+
+int get_cpuid(char *buffer, size_t sz)
+{
+ char *cpuid = _get_cpuid();
+ int ret = 0;
+
+ if (sz < strlen(cpuid)) {
Could this not segfault if cpuid is NULL?
yes, it is a problem. Will add NULL checking in next version.
Regards
Bibo Mao
Thanks,
Ian
+ ret = -EINVAL;
+ goto free;
+ }
+
+ scnprintf(buffer, sz, "%s", cpuid);
+free:
+ free(cpuid);
+ return ret;
+}
+
+char *get_cpuid_str(struct perf_pmu *pmu __maybe_unused)
+{
+ return _get_cpuid();
+}
diff --git a/tools/perf/arch/loongarch/util/kvm-stat.c b/tools/perf/arch/loongarch/util/kvm-stat.c
new file mode 100644
index 000000000000..2c21d73cd855
--- /dev/null
+++ b/tools/perf/arch/loongarch/util/kvm-stat.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <errno.h>
+#include <memory.h>
+#include <errno.h>
+#include "util/kvm-stat.h"
+#include "util/parse-events.h"
+#include "util/debug.h"
+#include "util/evsel.h"
+#include "util/evlist.h"
+#include "util/pmus.h"
+
+#define LOONGARCH_EXCEPTION_INT 0
+#define LOONGARCH_EXCEPTION_PIL 1
+#define LOONGARCH_EXCEPTION_PIS 2
+#define LOONGARCH_EXCEPTION_PIF 3
+#define LOONGARCH_EXCEPTION_PME 4
+#define LOONGARCH_EXCEPTION_FPD 15
+#define LOONGARCH_EXCEPTION_SXD 16
+#define LOONGARCH_EXCEPTION_ASXD 17
+#define LOONGARCH_EXCEPTION_GSPR 22
+#define LOONGARCH_EXCEPTION_CPUCFG 100
+#define LOONGARCH_EXCEPTION_CSR 101
+#define LOONGARCH_EXCEPTION_IOCSR 102
+#define LOONGARCH_EXCEPTION_IDLE 103
+#define LOONGARCH_EXCEPTION_OTHERS 104
+#define LOONGARCH_EXCEPTION_HVC 23
+
+#define loongarch_exception_type \
+ {LOONGARCH_EXCEPTION_INT, "Interrupt" }, \
+ {LOONGARCH_EXCEPTION_PIL, "Mem read" }, \
+ {LOONGARCH_EXCEPTION_PIS, "Mem store" }, \
+ {LOONGARCH_EXCEPTION_PIF, "Ifecth" }, \
+ {LOONGARCH_EXCEPTION_PME, "Mem modify" }, \
+ {LOONGARCH_EXCEPTION_FPD, "FPU" }, \
+ {LOONGARCH_EXCEPTION_SXD, "LSX" }, \
+ {LOONGARCH_EXCEPTION_ASXD, "LASX" }, \
+ {LOONGARCH_EXCEPTION_GSPR, "Privilege Error" }, \
+ {LOONGARCH_EXCEPTION_HVC, "Hypercall" }, \
+ {LOONGARCH_EXCEPTION_CPUCFG, "Cpucfg" }, \
+ {LOONGARCH_EXCEPTION_CSR, "Csr" }, \
+ {LOONGARCH_EXCEPTION_IOCSR, "Iocsr" }, \
+ {LOONGARCH_EXCEPTION_IDLE, "Idle" }, \
+ {LOONGARCH_EXCEPTION_OTHERS, "Others" }
+
+
+define_exit_reasons_table(loongarch_exit_reasons, loongarch_exception_type);
+
+const char *vcpu_id_str = "vcpu_id";
+const char *kvm_exit_reason = "reason";
+const char *kvm_entry_trace = "kvm:kvm_enter";
+const char *kvm_reenter_trace = "kvm:kvm_reenter";
+const char *kvm_exit_trace = "kvm:kvm_exit";
+
+const char *kvm_events_tp[] = {
+ "kvm:kvm_enter",
+ "kvm:kvm_reenter",
+ "kvm:kvm_exit",
+ "kvm:kvm_exit_gspr",
+ NULL,
+};
+
+static bool event_end(struct evsel *evsel,
+ struct perf_sample *sample __maybe_unused,
+ struct event_key *key __maybe_unused)
+{
+ /*
+ * LoongArch kvm is a little different with other architectures
+ *
+ * There is kvm:kvm_reenter and kvm:kvm_enter event adjacent with
+ * kvm:kvm_exit event.
+ * kvm:kvm_reenter means returning to guest immediately
+ * kvm:kvm_enter means returning to vmm and then to guest
+ */
+ return evsel__name_is(evsel, kvm_entry_trace) ||
+ evsel__name_is(evsel, kvm_reenter_trace);
+}
+
+static void event_gspr_get_key(struct evsel *evsel,
+ struct perf_sample *sample,
+ struct event_key *key)
+{
+ unsigned int insn;
+
+ key->key = LOONGARCH_EXCEPTION_OTHERS;
+ insn = evsel__intval(evsel, sample, "inst_word");
+ switch (insn >> 24) {
+ case 0:
+ /* cpucfg inst trap */
+ if ((insn >> 10) == 0x1b)
+ key->key = LOONGARCH_EXCEPTION_CPUCFG;
+ break;
+ case 4:
+ /* csr inst trap */
+ key->key = LOONGARCH_EXCEPTION_CSR;
+ break;
+ case 6:
+ /* iocsr inst trap */
+ if ((insn >> 15) == 0xc90)
+ key->key = LOONGARCH_EXCEPTION_IOCSR;
+ else if ((insn >> 15) == 0xc91)
+ /* idle inst trap */
+ key->key = LOONGARCH_EXCEPTION_IDLE;
+ break;
+ default:
+ key->key = LOONGARCH_EXCEPTION_OTHERS;
+ break;
+ }
+}
+
+static struct child_event_ops child_events[] = {
+ { .name = "kvm:kvm_exit_gspr",
+ .get_key = event_gspr_get_key },
+ { NULL, NULL },
+};
+
+static struct kvm_events_ops exit_events = {
+ .is_begin_event = exit_event_begin,
+ .is_end_event = event_end,
+ .child_ops = child_events,
+ .decode_key = exit_event_decode_key,
+ .name = "VM-EXIT"
+};
+
+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_isa = "loongarch64";
+ kvm->exit_reasons = loongarch_exit_reasons;
+ return 0;
+}
base-commit: f2f80ac809875855ac843f9e5e7480604b5cbff5
--
2.39.3