perf kvm: Events analysis tool

Add 'perf kvm stat' support to analyze kvm vmexit/mmio/ioport smartly Usage: - kvm stat run a command and gather performance counter statistics, it is the alias of perf stat - trace kvm events: perf kvm stat record, or, if other tracepoints are interesting as well, we can append the events like this: perf kvm stat record -e timer:* -a If many guests are running, we can track the specified guest by using -p or --pid, -a is used to track events generated by all guests. - show the result: perf kvm stat report The output example is following: 13005 13059 total 2 guests are running on the host Then, track the guest whose pid is 13059: ^C[ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.253 MB perf.data.guest (~11065 samples) ] See the vmexit events: Analyze events for all VCPUs: VM-EXIT Samples Samples% Time% Avg time APIC_ACCESS 460 70.55% 0.01% 22.44us ( +- 1.75% ) HLT 93 14.26% 99.98% 832077.26us ( +- 10.42% ) EXTERNAL_INTERRUPT 64 9.82% 0.00% 35.35us ( +- 14.21% ) PENDING_INTERRUPT 24 3.68% 0.00% 9.29us ( +- 31.39% ) CR_ACCESS 7 1.07% 0.00% 8.12us ( +- 5.76% ) IO_INSTRUCTION 3 0.46% 0.00% 18.00us ( +- 11.79% ) EXCEPTION_NMI 1 0.15% 0.00% 5.83us ( +- -nan% ) Total Samples:652, Total events handled time:77396109.80us. See the mmio events: Analyze events for all VCPUs: MMIO Access Samples Samples% Time% Avg time 0xfee00380:W 387 84.31% 79.28% 8.29us ( +- 3.32% ) 0xfee00300:W 24 5.23% 9.96% 16.79us ( +- 1.97% ) 0xfee00300:R 24 5.23% 7.83% 13.20us ( +- 3.00% ) 0xfee00310:W 24 5.23% 2.93% 4.94us ( +- 3.84% ) Total Samples:459, Total events handled time:4044.59us. See the ioport event: Analyze events for all VCPUs: IO Port Access Samples Samples% Time% Avg time 0xc050:POUT 3 100.00% 100.00% 13.75us ( +- 10.83% ) Total Samples:3, Total events handled time:41.26us. And, --vcpu is used to track the specified vcpu and --key is used to sort the result: Analyze events for VCPU 0: VM-EXIT Samples Samples% Time% Avg time HLT 27 13.85% 99.97% 405790.24us ( +- 12.70% ) EXTERNAL_INTERRUPT 13 6.67% 0.00% 27.94us ( +- 22.26% ) APIC_ACCESS 146 74.87% 0.03% 21.69us ( +- 2.91% ) IO_INSTRUCTION 2 1.03% 0.00% 17.77us ( +- 20.56% ) CR_ACCESS 2 1.03% 0.00% 8.55us ( +- 6.47% ) PENDING_INTERRUPT 5 2.56% 0.00% 6.27us ( +- 3.94% ) Total Samples:195, Total events handled time:10959950.90us. Signed-off-by: Dong Hao <haodong@linux.vnet.ibm.com> Signed-off-by: Runzhen Wang <runzhen@linux.vnet.ibm.com> [ Dong Hao <haodong@linux.vnet.ibm.com> Runzhen Wang <runzhen@linux.vnet.ibm.com>: - rebase it on current acme's tree - fix the compiling-error on i386 ] Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Acked-by: David Ahern <dsahern@gmail.com> Cc: Avi Kivity <avi@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: kvm@vger.kernel.org Cc: Runzhen Wang <runzhen@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1347870675-31495-4-git-send-email-haodong@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-08-18 02:22:47 -07:00 · 2012-09-21 12:51:22 -03:00
1 parent 26bf264e87
commit bcf6edcd6f
@@ -12,7 +12,7 @@ SYNOPSIS
 	[--guestkallsyms=<path> --guestmodules=<path> | --guestvmlinux=<path>]]
 	{top|record|report|diff|buildid-list}
 'perf kvm' [--host] [--guest] [--guestkallsyms=<path> --guestmodules=<path>
-	| --guestvmlinux=<path>] {top|record|report|diff|buildid-list}
+	| --guestvmlinux=<path>] {top|record|report|diff|buildid-list|stat}

 DESCRIPTION
 -----------
@@ -38,6 +38,18 @@ There are a couple of variants of perf kvm:
  so that other tools can be used to fetch packages with matching symbol tables
  for use by perf report.

+  'perf kvm stat <command>' to run a command and gather performance counter
+  statistics.
+  Especially, perf 'kvm stat record/report' generates a statistical analysis
+  of KVM events. Currently, vmexit, mmio and ioport events are supported.
+  'perf kvm stat record <command>' records kvm events and the events between
+  start and end <command>.
+  And this command produces a file which contains tracing results of kvm
+  events.
+
+  'perf kvm stat report' reports statistical data which includes events
+  handled time, samples, and so on.
+
 OPTIONS
 -------
 -i::
@@ -68,7 +80,21 @@ OPTIONS
 --guestvmlinux=<path>::
 	Guest os kernel vmlinux.

+STAT REPORT OPTIONS
+-------------------
+--vcpu=<value>::
+       analyze events which occures on this vcpu. (default: all vcpus)
+
+--events=<value>::
+       events to be analyzed. Possible values: vmexit, mmio, ioport.
+       (default: vmexit)
+-k::
+--key=<value>::
+       Sorting key. Possible values: sample (default, sort by samples
+       number), time (sort by average time).
+
 SEE ALSO
 --------
 linkperf:perf-top[1], linkperf:perf-record[1], linkperf:perf-report[1],
-linkperf:perf-diff[1], linkperf:perf-buildid-list[1]
+linkperf:perf-diff[1], linkperf:perf-buildid-list[1],
+linkperf:perf-stat[1]
@@ -16,3 +16,6 @@ arch/*/lib/memset*.S
 include/linux/poison.h
 include/linux/magic.h
 include/linux/hw_breakpoint.h
+arch/x86/include/asm/svm.h
+arch/x86/include/asm/vmx.h
+arch/x86/include/asm/kvm_host.h
@@ -1673,6 +1673,11 @@ static int process_build_id(struct perf_file_section *section,
 	return 0;
 }

+static char *read_cpuid(struct perf_header *ph, int fd)
+{
+	return do_read_string(fd, ph);
+}
+
 static struct perf_evsel *
 perf_evlist__find_by_index(struct perf_evlist *evlist, int idx)
 {
@@ -1726,6 +1731,7 @@ process_event_desc(struct perf_file_section *section __maybe_unused,
 struct feature_ops {
 	int (*write)(int fd, struct perf_header *h, struct perf_evlist *evlist);
 	void (*print)(struct perf_header *h, int fd, FILE *fp);
+	char *(*read)(struct perf_header *h, int fd);
 	int (*process)(struct perf_file_section *section,
 		       struct perf_header *h, int feat, int fd, void *data);
 	const char *name;
@@ -1740,6 +1746,9 @@ struct feature_ops {
 #define FEAT_OPF(n, func) \
 	[n] = { .name = #n, .write = write_##func, .print = print_##func, \
 		.full_only = true }
+#define FEAT_OPA_R(n, func) \
+	[n] = { .name = #n, .write = write_##func, .print = print_##func, \
+		.read  = read_##func }

 /* feature_ops not implemented: */
 #define print_tracing_data	NULL
@@ -1754,7 +1763,7 @@ static const struct feature_ops feat_ops[HEADER_LAST_FEATURE] = {
 	FEAT_OPA(HEADER_ARCH,		arch),
 	FEAT_OPA(HEADER_NRCPUS,		nrcpus),
 	FEAT_OPA(HEADER_CPUDESC,	cpudesc),
-	FEAT_OPA(HEADER_CPUID,		cpuid),
+	FEAT_OPA_R(HEADER_CPUID,	cpuid),
 	FEAT_OPA(HEADER_TOTAL_MEM,	total_mem),
 	FEAT_OPP(HEADER_EVENT_DESC,	event_desc),
 	FEAT_OPA(HEADER_CMDLINE,	cmdline),
@@ -1809,6 +1818,54 @@ int perf_header__fprintf_info(struct perf_session *session, FILE *fp, bool full)
 	return 0;
 }

+struct header_read_data {
+	int feat;
+	char *result;
+};
+
+static int perf_file_section__read_feature(struct perf_file_section *section,
+				struct perf_header *ph,
+				int feat, int fd, void *data)
+{
+	struct header_read_data *hd = data;
+
+	if (feat != hd->feat)
+		return 0;
+
+	if (lseek(fd, section->offset, SEEK_SET) == (off_t)-1) {
+		pr_debug("Failed to lseek to %" PRIu64 " offset for feature "
+				"%d, continuing...\n", section->offset, feat);
+	return 0;
+	}
+
+	if (feat >= HEADER_LAST_FEATURE) {
+		pr_warning("unknown feature %d\n", feat);
+		return 0;
+	}
+
+	if (!feat_ops[feat].read) {
+		pr_warning("read is not supported for feature %d\n", feat);
+		return 0;
+	}
+
+	hd->result = feat_ops[feat].read(ph, fd);
+	return 0;
+}
+
+char *perf_header__read_feature(struct perf_session *session, int feat)
+{
+	struct perf_header *header = &session->header;
+	struct header_read_data hd;
+	int fd = session->fd;
+
+	hd.feat = feat;
+	hd.result = NULL;
+
+	perf_header__process_sections(header, fd, &hd,
+				perf_file_section__read_feature);
+	return hd.result;
+}
+
 static int do_write_feat(int fd, struct perf_header *h, int type,
 			 struct perf_file_section **p,
 			 struct perf_evlist *evlist)
@@ -94,6 +94,7 @@ int perf_header__process_sections(struct perf_header *header, int fd,
 				  int feat, int fd, void *data));

 int perf_header__fprintf_info(struct perf_session *s, FILE *fp, bool full);
+char *perf_header__read_feature(struct perf_session *session, int feat);

 int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
 			  const char *name, bool is_kallsyms, bool is_vdso);
@@ -16,6 +16,8 @@ struct thread {
 	bool			comm_set;
 	char			*comm;
 	int			comm_len;
+
+	void			*priv;
 };

 struct machine;