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* [RFC PATCH v5 00/11] Add VM kernel tracing over vsockets and FIFOs
@ 2019-02-04  6:58 Slavomir Kaslev
  2019-02-04  6:58 ` [RFC PATCH v5 01/11] trace-cmd: Detect if vsockets are available Slavomir Kaslev
                   ` (11 more replies)
  0 siblings, 12 replies; 13+ messages in thread
From: Slavomir Kaslev @ 2019-02-04  6:58 UTC (permalink / raw)
  To: linux-trace-devel; +Cc: rostedt, slavomir.kaslev, tstoyanov, ykaradzhov

This patchset adds support for tracing guest kernels to trace-cmd.

Changes in v5:
 - add FIFOs transport for tracing data
 - fixed a bug in tracecmd_msg_wait_close

Changes in v4:
 - detect and use splice(2) on vsock sockets if possible
 - switch port numbers to unsigned int
 - trace-cmd record --date flag is now set for all guests if provided by the user
 - removed grow_cap and exponential buffer size growth

Changes in v3:
 - addressed Steven's feedback
 - detect and disable guest tracing if <linux/vm_sockets.h> is not available
 - the --date flag is now treated as global for all guest instances
 - fixed a bug that caused --date to be ignored for host tracing data when tracing guests

Changes in v2:
 - rebased on top of protocol V3
 - fixed system clock timestamps with the --date flag


Slavomir Kaslev (10):
  trace-cmd: Add tracecmd_create_recorder_virt function
  trace-cmd: Add TRACE_REQ and TRACE_RESP messages
  trace-cmd: Add buffer instance flags for tracing in guest and agent
    context
  trace-cmd: Add VM kernel tracing over vsockets transport
  trace-cmd: Use splice(2) for vsockets if available
  trace-cmd: Add `trace-cmd setup-guest` command
  trace-cmd: Try to autodetect number of guest CPUs in setup-guest if
    not specified
  trace-cmd: Make setup-guest auto attach FIFOs to the guest VM config
  trace-cmd: Set both input and output to non-blocking when recording is
    stopped
  trace-cmd: Add VM tracing over FIFOs transport

Steven Rostedt (VMware) (1):
  trace-cmd: Detect if vsockets are available

 Makefile                       |   7 +
 include/trace-cmd/trace-cmd.h  |  17 +-
 lib/trace-cmd/trace-recorder.c |  69 ++-
 tracecmd/Makefile              |   7 +-
 tracecmd/include/trace-local.h |  26 ++
 tracecmd/trace-agent.c         | 257 +++++++++++
 tracecmd/trace-cmd.c           |   4 +
 tracecmd/trace-msg.c           | 222 +++++++++-
 tracecmd/trace-record.c        | 759 +++++++++++++++++++++++++++++++--
 tracecmd/trace-setup-guest.c   | 243 +++++++++++
 tracecmd/trace-usage.c         |  21 +-
 11 files changed, 1557 insertions(+), 75 deletions(-)
 create mode 100644 tracecmd/trace-agent.c
 create mode 100644 tracecmd/trace-setup-guest.c

--
2.19.1

^ permalink raw reply	[flat|nested] 13+ messages in thread

* [RFC PATCH v5 01/11] trace-cmd: Detect if vsockets are available
  2019-02-04  6:58 [RFC PATCH v5 00/11] Add VM kernel tracing over vsockets and FIFOs Slavomir Kaslev
@ 2019-02-04  6:58 ` Slavomir Kaslev
  2019-02-04  6:58 ` [RFC PATCH v5 02/11] trace-cmd: Add tracecmd_create_recorder_virt function Slavomir Kaslev
                   ` (10 subsequent siblings)
  11 siblings, 0 replies; 13+ messages in thread
From: Slavomir Kaslev @ 2019-02-04  6:58 UTC (permalink / raw)
  To: linux-trace-devel; +Cc: rostedt, slavomir.kaslev, tstoyanov, ykaradzhov

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

Detect and define VSOCK if vsockets are available on the system.
This macro is used to disable VM remote tracing features on older kernels.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com>
---
 Makefile | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Makefile b/Makefile
index f0f7e92..ce16b83 100644
--- a/Makefile
+++ b/Makefile
@@ -204,6 +204,13 @@ CFLAGS ?= -g -Wall
 CPPFLAGS ?=
 LDFLAGS ?=
 
+VSOCK_DEFINED := $(shell if (echo "\#include <linux/vm_sockets.h>" | $(CC) -E - >/dev/null 2>&1) ; then echo 1; else echo 0 ; fi)
+
+export VSOCK_DEFINED
+ifeq ($(VSOCK_DEFINED), 1)
+CFLAGS += -DVSOCK
+endif
+
 export CFLAGS
 export INCLUDES
 
-- 
2.19.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [RFC PATCH v5 02/11] trace-cmd: Add tracecmd_create_recorder_virt function
  2019-02-04  6:58 [RFC PATCH v5 00/11] Add VM kernel tracing over vsockets and FIFOs Slavomir Kaslev
  2019-02-04  6:58 ` [RFC PATCH v5 01/11] trace-cmd: Detect if vsockets are available Slavomir Kaslev
@ 2019-02-04  6:58 ` Slavomir Kaslev
  2019-02-04  6:58 ` [RFC PATCH v5 03/11] trace-cmd: Add TRACE_REQ and TRACE_RESP messages Slavomir Kaslev
                   ` (9 subsequent siblings)
  11 siblings, 0 replies; 13+ messages in thread
From: Slavomir Kaslev @ 2019-02-04  6:58 UTC (permalink / raw)
  To: linux-trace-devel; +Cc: rostedt, slavomir.kaslev, tstoyanov, ykaradzhov

Add tracecmd_create_recorder_virt function that will be used for
tracing VM guests.

Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com>
---
 include/trace-cmd/trace-cmd.h  |  1 +
 lib/trace-cmd/trace-recorder.c | 53 ++++++++++++++++++++++++----------
 2 files changed, 39 insertions(+), 15 deletions(-)

diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h
index 86b9b53..8b43462 100644
--- a/include/trace-cmd/trace-cmd.h
+++ b/include/trace-cmd/trace-cmd.h
@@ -277,6 +277,7 @@ enum {
 void tracecmd_free_recorder(struct tracecmd_recorder *recorder);
 struct tracecmd_recorder *tracecmd_create_recorder(const char *file, int cpu, unsigned flags);
 struct tracecmd_recorder *tracecmd_create_recorder_fd(int fd, int cpu, unsigned flags);
+struct tracecmd_recorder *tracecmd_create_recorder_virt(const char *file, int cpu, unsigned flags, int trace_fd);
 struct tracecmd_recorder *tracecmd_create_recorder_maxkb(const char *file, int cpu, unsigned flags, int maxkb);
 struct tracecmd_recorder *tracecmd_create_buffer_recorder_fd(int fd, int cpu, unsigned flags, const char *buffer);
 struct tracecmd_recorder *tracecmd_create_buffer_recorder(const char *file, int cpu, unsigned flags, const char *buffer);
diff --git a/lib/trace-cmd/trace-recorder.c b/lib/trace-cmd/trace-recorder.c
index 5331925..83a12f4 100644
--- a/lib/trace-cmd/trace-recorder.c
+++ b/lib/trace-cmd/trace-recorder.c
@@ -148,16 +148,22 @@ tracecmd_create_buffer_recorder_fd2(int fd, int fd2, int cpu, unsigned flags,
 	recorder->fd1 = fd;
 	recorder->fd2 = fd2;
 
-	if (flags & TRACECMD_RECORD_SNAPSHOT)
-		ret = asprintf(&path, "%s/per_cpu/cpu%d/snapshot_raw", buffer, cpu);
-	else
-		ret = asprintf(&path, "%s/per_cpu/cpu%d/trace_pipe_raw", buffer, cpu);
-	if (ret < 0)
-		goto out_free;
+	if (buffer) {
+		if (flags & TRACECMD_RECORD_SNAPSHOT)
+			ret = asprintf(&path, "%s/per_cpu/cpu%d/snapshot_raw",
+				       buffer, cpu);
+		else
+			ret = asprintf(&path, "%s/per_cpu/cpu%d/trace_pipe_raw",
+				       buffer, cpu);
+		if (ret < 0)
+			goto out_free;
+
+		recorder->trace_fd = open(path, O_RDONLY);
+		free(path);
 
-	recorder->trace_fd = open(path, O_RDONLY);
-	if (recorder->trace_fd < 0)
-		goto out_free;
+		if (recorder->trace_fd < 0)
+			goto out_free;
+	}
 
 	if ((recorder->flags & TRACECMD_RECORD_NOSPLICE) == 0) {
 		ret = pipe(recorder->brass);
@@ -177,13 +183,9 @@ tracecmd_create_buffer_recorder_fd2(int fd, int fd2, int cpu, unsigned flags,
 		recorder->pipe_size = pipe_size;
 	}
 
-	free(path);
-
 	return recorder;
 
  out_free:
-	free(path);
-
 	tracecmd_free_recorder(recorder);
 	return NULL;
 }
@@ -194,8 +196,9 @@ tracecmd_create_buffer_recorder_fd(int fd, int cpu, unsigned flags, const char *
 	return tracecmd_create_buffer_recorder_fd2(fd, -1, cpu, flags, buffer, 0);
 }
 
-struct tracecmd_recorder *
-tracecmd_create_buffer_recorder(const char *file, int cpu, unsigned flags, const char *buffer)
+static struct tracecmd_recorder *
+__tracecmd_create_buffer_recorder(const char *file, int cpu, unsigned flags,
+				  const char *buffer)
 {
 	struct tracecmd_recorder *recorder;
 	int fd;
@@ -258,6 +261,26 @@ tracecmd_create_buffer_recorder_maxkb(const char *file, int cpu, unsigned flags,
 	goto out;
 }
 
+struct tracecmd_recorder *
+tracecmd_create_buffer_recorder(const char *file, int cpu, unsigned flags,
+				const char *buffer)
+{
+	return __tracecmd_create_buffer_recorder(file, cpu, flags, buffer);
+}
+
+struct tracecmd_recorder *
+tracecmd_create_recorder_virt(const char *file, int cpu, unsigned flags,
+			      int trace_fd)
+{
+	struct tracecmd_recorder *recorder;
+
+	recorder = __tracecmd_create_buffer_recorder(file, cpu, flags, NULL);
+	if (recorder)
+		recorder->trace_fd = trace_fd;
+
+	return recorder;
+}
+
 struct tracecmd_recorder *tracecmd_create_recorder_fd(int fd, int cpu, unsigned flags)
 {
 	const char *tracing;
-- 
2.19.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [RFC PATCH v5 03/11] trace-cmd: Add TRACE_REQ and TRACE_RESP messages
  2019-02-04  6:58 [RFC PATCH v5 00/11] Add VM kernel tracing over vsockets and FIFOs Slavomir Kaslev
  2019-02-04  6:58 ` [RFC PATCH v5 01/11] trace-cmd: Detect if vsockets are available Slavomir Kaslev
  2019-02-04  6:58 ` [RFC PATCH v5 02/11] trace-cmd: Add tracecmd_create_recorder_virt function Slavomir Kaslev
@ 2019-02-04  6:58 ` Slavomir Kaslev
  2019-02-04  6:58 ` [RFC PATCH v5 04/11] trace-cmd: Add buffer instance flags for tracing in guest and agent context Slavomir Kaslev
                   ` (8 subsequent siblings)
  11 siblings, 0 replies; 13+ messages in thread
From: Slavomir Kaslev @ 2019-02-04  6:58 UTC (permalink / raw)
  To: linux-trace-devel; +Cc: rostedt, slavomir.kaslev, tstoyanov, ykaradzhov

Add TRACE_REQ and TRACE_RESP messages which are used for initiating guest VM
tracing.

Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com>
---
 include/trace-cmd/trace-cmd.h |  16 ++-
 tracecmd/trace-msg.c          | 213 +++++++++++++++++++++++++++++++++-
 2 files changed, 224 insertions(+), 5 deletions(-)

diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h
index 8b43462..7664074 100644
--- a/include/trace-cmd/trace-cmd.h
+++ b/include/trace-cmd/trace-cmd.h
@@ -326,7 +326,7 @@ int tracecmd_msg_send_init_data(struct tracecmd_msg_handle *msg_handle,
 int tracecmd_msg_data_send(struct tracecmd_msg_handle *msg_handle,
 			       const char *buf, int size);
 int tracecmd_msg_finish_sending_data(struct tracecmd_msg_handle *msg_handle);
-void tracecmd_msg_send_close_msg(struct tracecmd_msg_handle *msg_handle);
+int tracecmd_msg_send_close_msg(struct tracecmd_msg_handle *msg_handle);
 
 /* for server */
 int tracecmd_msg_initial_setting(struct tracecmd_msg_handle *msg_handle);
@@ -337,6 +337,20 @@ int tracecmd_msg_collect_data(struct tracecmd_msg_handle *msg_handle, int ofd);
 bool tracecmd_msg_done(struct tracecmd_msg_handle *msg_handle);
 void tracecmd_msg_set_done(struct tracecmd_msg_handle *msg_handle);
 
+int tracecmd_msg_send_trace_req(struct tracecmd_msg_handle *msg_handle,
+				int argc, char **argv);
+int tracecmd_msg_recv_trace_req(struct tracecmd_msg_handle *msg_handle,
+				int *argc, char ***argv);
+
+int tracecmd_msg_send_trace_resp(struct tracecmd_msg_handle *msg_handle,
+				 int nr_cpus, int page_size,
+				 unsigned int *ports);
+int tracecmd_msg_recv_trace_resp(struct tracecmd_msg_handle *msg_handle,
+				 int *nr_cpus, int *page_size,
+				 unsigned int **ports);
+
+int tracecmd_msg_wait_close(struct tracecmd_msg_handle *msg_handle);
+
 /* --- Plugin handling --- */
 extern struct tep_plugin_option trace_ftrace_options[];
 
diff --git a/tracecmd/trace-msg.c b/tracecmd/trace-msg.c
index 529ae2a..8b6fb03 100644
--- a/tracecmd/trace-msg.c
+++ b/tracecmd/trace-msg.c
@@ -16,6 +16,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
+#include <string.h>
 #include <unistd.h>
 #include <arpa/inet.h>
 #include <sys/types.h>
@@ -79,6 +80,16 @@ struct tracecmd_msg_rinit {
 	be32 cpus;
 } __attribute__((packed));
 
+struct tracecmd_msg_trace_req {
+	be32 flags;
+	be32 argc;
+} __attribute__((packed));
+
+struct tracecmd_msg_trace_resp {
+	be32 cpus;
+	be32 page_size;
+} __attribute__((packed));
+
 struct tracecmd_msg_header {
 	be32	size;
 	be32	cmd;
@@ -90,7 +101,9 @@ struct tracecmd_msg_header {
 	C(TINIT,	1,	sizeof(struct tracecmd_msg_tinit)),	\
 	C(RINIT,	2,	sizeof(struct tracecmd_msg_rinit)),	\
 	C(SEND_DATA,	3,	0),					\
-	C(FIN_DATA,	4,	0),
+	C(FIN_DATA,	4,	0),					\
+	C(TRACE_REQ,	5,	sizeof(struct tracecmd_msg_trace_req)),	\
+	C(TRACE_RESP,	6,	sizeof(struct tracecmd_msg_trace_resp)),
 
 #undef C
 #define C(a,b,c)	MSG_##a = b
@@ -122,6 +135,8 @@ struct tracecmd_msg {
 	union {
 		struct tracecmd_msg_tinit	tinit;
 		struct tracecmd_msg_rinit	rinit;
+		struct tracecmd_msg_trace_req	trace_req;
+		struct tracecmd_msg_trace_resp	trace_resp;
 	};
 	union {
 		struct tracecmd_msg_opt		*opt;
@@ -569,12 +584,12 @@ int tracecmd_msg_send_port_array(struct tracecmd_msg_handle *msg_handle,
 	return 0;
 }
 
-void tracecmd_msg_send_close_msg(struct tracecmd_msg_handle *msg_handle)
+int tracecmd_msg_send_close_msg(struct tracecmd_msg_handle *msg_handle)
 {
 	struct tracecmd_msg msg;
 
 	tracecmd_msg_init(MSG_CLOSE, &msg);
-	tracecmd_msg_send(msg_handle->fd, &msg);
+	return tracecmd_msg_send(msg_handle->fd, &msg);
 }
 
 int tracecmd_msg_data_send(struct tracecmd_msg_handle *msg_handle,
@@ -684,7 +699,7 @@ int tracecmd_msg_collect_data(struct tracecmd_msg_handle *msg_handle, int ofd)
 	int ret;
 
 	ret = tracecmd_msg_read_data(msg_handle, ofd);
-	if (ret)
+	if (ret < 0)
 		goto error;
 
 	/* check the finish message of the client */
@@ -715,3 +730,193 @@ error:
 	msg_free(&msg);
 	return ret;
 }
+
+static int make_trace_req(struct tracecmd_msg *msg, int argc, char **argv)
+{
+	size_t args_size = 0;
+	char *p;
+	int i;
+
+	for (i = 0; i < argc; i++)
+		args_size += strlen(argv[i]) + 1;
+
+	msg->hdr.size = htonl(ntohl(msg->hdr.size) + args_size);
+	msg->trace_req.argc = htonl(argc);
+	msg->buf = calloc(args_size, 1);
+	if (!msg->buf)
+		return -ENOMEM;
+
+	p = msg->buf;
+	for (i = 0; i < argc; i++)
+		p = stpcpy(p, argv[i]) + 1;
+
+	return 0;
+}
+
+int tracecmd_msg_send_trace_req(struct tracecmd_msg_handle *msg_handle,
+				int argc, char **argv)
+{
+	struct tracecmd_msg msg;
+	int ret;
+
+	tracecmd_msg_init(MSG_TRACE_REQ, &msg);
+	ret = make_trace_req(&msg, argc, argv);
+	if (ret < 0)
+		return ret;
+
+	return tracecmd_msg_send(msg_handle->fd, &msg);
+}
+
+ /*
+  * NOTE: On success, the returned `argv` should be freed with:
+  *     free(argv[0]);
+  *     free(argv);
+  */
+int tracecmd_msg_recv_trace_req(struct tracecmd_msg_handle *msg_handle,
+				int *argc, char ***argv)
+{
+	struct tracecmd_msg msg;
+	char *p, *buf_end, **args;
+	int i, ret, nr_args;
+	size_t buf_len;
+
+	ret = tracecmd_msg_recv(msg_handle->fd, &msg);
+	if (ret < 0)
+		return ret;
+
+	if (ntohl(msg.hdr.cmd) != MSG_TRACE_REQ)
+		goto out;
+
+	if (ntohl(msg.trace_req.argc) < 0)
+		goto out;
+
+	buf_len = ntohl(msg.hdr.size) - MSG_HDR_LEN - ntohl(msg.hdr.cmd_size);
+	buf_end = (char *)msg.buf + buf_len;
+	p = msg.buf;
+	nr_args = ntohl(msg.trace_req.argc);
+	args = calloc(nr_args, sizeof(*args));
+	if (!args) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	for (i = 0; i < nr_args; i++) {
+		if (p >= buf_end) {
+			ret = -1;
+			free(args);
+			goto out;
+		}
+
+		args[i] = p;
+		p = strchr(p, '\0');
+		p++;
+	}
+
+	/*
+	 * On success we're passing msg.buf to the caller through argv[0] so we
+	 * reset it here to avoid getting it freed below.
+	 */
+	msg.buf = NULL;
+	*argc = nr_args;
+	*argv = args;
+	ret = 0;
+
+out:
+	msg_free(&msg);
+	return ret;
+}
+
+static int make_trace_resp(struct tracecmd_msg *msg,
+			   int page_size, int nr_cpus, unsigned int *ports)
+{
+	int ports_size = nr_cpus * sizeof(*msg->port_array);
+	int i;
+
+	msg->hdr.size = htonl(ntohl(msg->hdr.size) + ports_size);
+	msg->trace_resp.cpus = htonl(nr_cpus);
+	msg->trace_resp.page_size = htonl(page_size);
+
+	msg->port_array = malloc(ports_size);
+	if (!msg->port_array)
+		return -ENOMEM;
+
+	for (i = 0; i < nr_cpus; i++)
+		msg->port_array[i] = htonl(ports[i]);
+
+	return 0;
+}
+
+int tracecmd_msg_send_trace_resp(struct tracecmd_msg_handle *msg_handle,
+				 int nr_cpus, int page_size,
+				 unsigned int *ports)
+{
+	struct tracecmd_msg msg;
+	int ret;
+
+	tracecmd_msg_init(MSG_TRACE_RESP, &msg);
+	ret = make_trace_resp(&msg, page_size, nr_cpus, ports);
+	if (ret < 0)
+		return ret;
+
+	return tracecmd_msg_send(msg_handle->fd, &msg);
+}
+
+int tracecmd_msg_recv_trace_resp(struct tracecmd_msg_handle *msg_handle,
+				 int *nr_cpus, int *page_size,
+				 unsigned int **ports)
+{
+	struct tracecmd_msg msg;
+	size_t buf_len;
+	int i, ret;
+
+	ret = tracecmd_msg_recv(msg_handle->fd, &msg);
+	if (ret < 0)
+		return ret;
+
+	if (ntohl(msg.hdr.cmd) != MSG_TRACE_RESP) {
+		ret = -1;
+		goto out;
+	}
+
+	buf_len = ntohl(msg.hdr.size) - MSG_HDR_LEN - ntohl(msg.hdr.cmd_size);
+	if (buf_len <= 0 ||
+	    buf_len != sizeof(*msg.port_array) * ntohl(msg.trace_resp.cpus)) {
+		ret = -1;
+		goto out;
+	}
+
+	*nr_cpus = ntohl(msg.trace_resp.cpus);
+	*page_size = ntohl(msg.trace_resp.page_size);
+	*ports = calloc(*nr_cpus, sizeof(**ports));
+	if (!*ports) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	for (i = 0; i < *nr_cpus; i++)
+		(*ports)[i] = ntohl(msg.port_array[i]);
+
+	ret = 0;
+
+out:
+	msg_free(&msg);
+	return ret;
+}
+
+int tracecmd_msg_wait_close(struct tracecmd_msg_handle *msg_handle)
+{
+	struct tracecmd_msg msg;
+	int ret;
+
+	memset(&msg, 0, sizeof(msg));
+	for (;;) {
+		ret = tracecmd_msg_recv(msg_handle->fd, &msg);
+		if (ret < 0)
+			return ret;
+
+		if (ntohl(msg.hdr.cmd) == MSG_CLOSE)
+			return 0;
+
+		msg_free(&msg);
+	}
+
+	return -1;
+}
-- 
2.19.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [RFC PATCH v5 04/11] trace-cmd: Add buffer instance flags for tracing in guest and agent context
  2019-02-04  6:58 [RFC PATCH v5 00/11] Add VM kernel tracing over vsockets and FIFOs Slavomir Kaslev
                   ` (2 preceding siblings ...)
  2019-02-04  6:58 ` [RFC PATCH v5 03/11] trace-cmd: Add TRACE_REQ and TRACE_RESP messages Slavomir Kaslev
@ 2019-02-04  6:58 ` Slavomir Kaslev
  2019-02-04  6:58 ` [RFC PATCH v5 05/11] trace-cmd: Add VM kernel tracing over vsockets transport Slavomir Kaslev
                   ` (7 subsequent siblings)
  11 siblings, 0 replies; 13+ messages in thread
From: Slavomir Kaslev @ 2019-02-04  6:58 UTC (permalink / raw)
  To: linux-trace-devel; +Cc: rostedt, slavomir.kaslev, tstoyanov, ykaradzhov

Add BUFFER_FL_GUEST and BUFFER_FL_AGENT flags to differentiate when
trace-record.c is being called to trace guest or the VM tracing agent.

Also disable functions talking to the local tracefs when called in recording
guest instances context.

Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com>
---
 tracecmd/include/trace-local.h |  2 ++
 tracecmd/trace-record.c        | 55 ++++++++++++++++++++++++++++++++--
 2 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h
index a1a06e9..f19c8bb 100644
--- a/tracecmd/include/trace-local.h
+++ b/tracecmd/include/trace-local.h
@@ -149,6 +149,8 @@ char *strstrip(char *str);
 enum buffer_instance_flags {
 	BUFFER_FL_KEEP		= 1 << 0,
 	BUFFER_FL_PROFILE	= 1 << 1,
+	BUFFER_FL_GUEST		= 1 << 2,
+	BUFFER_FL_AGENT		= 1 << 3,
 };
 
 struct func_list {
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index 3034a4b..b911c34 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -781,6 +781,9 @@ static void __clear_trace(struct buffer_instance *instance)
 	FILE *fp;
 	char *path;
 
+	if (instance->flags & BUFFER_FL_GUEST)
+		return;
+
 	/* reset the trace */
 	path = get_instance_file(instance, "trace");
 	fp = fopen(path, "w");
@@ -1264,6 +1267,9 @@ set_plugin_instance(struct buffer_instance *instance, const char *name)
 	char *path;
 	char zero = '0';
 
+	if (instance->flags & BUFFER_FL_GUEST)
+		return;
+
 	path = get_instance_file(instance, "current_tracer");
 	fp = fopen(path, "w");
 	if (!fp) {
@@ -1360,6 +1366,9 @@ static void disable_func_stack_trace_instance(struct buffer_instance *instance)
 	int size;
 	int ret;
 
+	if (instance->flags & BUFFER_FL_GUEST)
+		return;
+
 	path = get_instance_file(instance, "current_tracer");
 	ret = stat(path, &st);
 	tracecmd_put_tracing_file(path);
@@ -1553,6 +1562,9 @@ reset_events_instance(struct buffer_instance *instance)
 	int i;
 	int ret;
 
+	if (instance->flags & BUFFER_FL_GUEST)
+		return;
+
 	if (use_old_event_method()) {
 		/* old way only had top instance */
 		if (!is_top_instance(instance))
@@ -1904,6 +1916,9 @@ static void write_tracing_on(struct buffer_instance *instance, int on)
 	int ret;
 	int fd;
 
+	if (instance->flags & BUFFER_FL_GUEST)
+		return;
+
 	fd = open_tracing_on(instance);
 	if (fd < 0)
 		return;
@@ -1923,6 +1938,9 @@ static int read_tracing_on(struct buffer_instance *instance)
 	char buf[10];
 	int ret;
 
+	if (instance->flags & BUFFER_FL_GUEST)
+		return -1;
+
 	fd = open_tracing_on(instance);
 	if (fd < 0)
 		return fd;
@@ -2156,6 +2174,9 @@ static void set_mask(struct buffer_instance *instance)
 	int fd;
 	int ret;
 
+	if (instance->flags & BUFFER_FL_GUEST)
+		return;
+
 	if (!instance->cpumask)
 		return;
 
@@ -2186,6 +2207,9 @@ static void enable_events(struct buffer_instance *instance)
 {
 	struct event_list *event;
 
+	if (instance->flags & BUFFER_FL_GUEST)
+		return;
+
 	for (event = instance->events; event; event = event->next) {
 		if (!event->neg)
 			update_event(event, event->filter, 0, '1');
@@ -2209,6 +2233,9 @@ static void set_clock(struct buffer_instance *instance)
 	char *content;
 	char *str;
 
+	if (instance->flags & BUFFER_FL_GUEST)
+		return;
+
 	if (!instance->clock)
 		return;
 
@@ -2238,6 +2265,9 @@ static void set_max_graph_depth(struct buffer_instance *instance, char *max_grap
 	char *path;
 	int ret;
 
+	if (instance->flags & BUFFER_FL_GUEST)
+		return;
+
 	path = get_instance_file(instance, "max_graph_depth");
 	reset_save_file(path, RESET_DEFAULT_PRIO);
 	tracecmd_put_tracing_file(path);
@@ -2463,6 +2493,9 @@ static void expand_event_instance(struct buffer_instance *instance)
 	struct event_list *compressed_list = instance->events;
 	struct event_list *event;
 
+	if (instance->flags & BUFFER_FL_GUEST)
+		return;
+
 	reset_event_list(instance);
 
 	while (compressed_list) {
@@ -3336,6 +3369,9 @@ static void set_funcs(struct buffer_instance *instance)
 	int set_notrace = 0;
 	int ret;
 
+	if (instance->flags & BUFFER_FL_GUEST)
+		return;
+
 	ret = write_func_file(instance, "set_ftrace_filter", &instance->filter_funcs);
 	if (ret < 0)
 		die("set_ftrace_filter does not exist. Can not filter functions");
@@ -3632,6 +3668,9 @@ static void set_buffer_size_instance(struct buffer_instance *instance)
 	int ret;
 	int fd;
 
+	if (instance->flags & BUFFER_FL_GUEST)
+		return;
+
 	if (!buffer_size)
 		return;
 
@@ -3829,6 +3868,9 @@ static void make_instances(void)
 	int ret;
 
 	for_each_instance(instance) {
+		if (instance->flags & BUFFER_FL_GUEST)
+			continue;
+
 		path = get_instance_dir(instance);
 		ret = stat(path, &st);
 		if (ret < 0) {
@@ -3850,7 +3892,7 @@ void tracecmd_remove_instances(void)
 
 	for_each_instance(instance) {
 		/* Only delete what we created */
-		if (instance->flags & BUFFER_FL_KEEP)
+		if (instance->flags & (BUFFER_FL_KEEP | BUFFER_FL_GUEST))
 			continue;
 		if (instance->tracing_on_fd > 0) {
 			close(instance->tracing_on_fd);
@@ -3932,7 +3974,7 @@ static void check_function_plugin(void)
 
 static int __check_doing_something(struct buffer_instance *instance)
 {
-	return (instance->flags & BUFFER_FL_PROFILE) ||
+	return (instance->flags & (BUFFER_FL_PROFILE | BUFFER_FL_GUEST)) ||
 		instance->plugin || instance->events;
 }
 
@@ -3954,6 +3996,9 @@ update_plugin_instance(struct buffer_instance *instance,
 {
 	const char *plugin = instance->plugin;
 
+	if (instance->flags & BUFFER_FL_GUEST)
+		return;
+
 	if (!plugin)
 		return;
 
@@ -4053,6 +4098,9 @@ static void record_stats(void)
 	int cpu;
 
 	for_all_instances(instance) {
+		if (instance->flags & BUFFER_FL_GUEST)
+			continue;
+
 		s_save = instance->s_save;
 		s_print = instance->s_print;
 		for (cpu = 0; cpu < instance->cpu_count; cpu++) {
@@ -4079,6 +4127,9 @@ static void destroy_stats(void)
 	int cpu;
 
 	for_all_instances(instance) {
+		if (instance->flags & BUFFER_FL_GUEST)
+			continue;
+
 		for (cpu = 0; cpu < instance->cpu_count; cpu++) {
 			trace_seq_destroy(&instance->s_save[cpu]);
 			trace_seq_destroy(&instance->s_print[cpu]);
-- 
2.19.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [RFC PATCH v5 05/11] trace-cmd: Add VM kernel tracing over vsockets transport
  2019-02-04  6:58 [RFC PATCH v5 00/11] Add VM kernel tracing over vsockets and FIFOs Slavomir Kaslev
                   ` (3 preceding siblings ...)
  2019-02-04  6:58 ` [RFC PATCH v5 04/11] trace-cmd: Add buffer instance flags for tracing in guest and agent context Slavomir Kaslev
@ 2019-02-04  6:58 ` Slavomir Kaslev
  2019-02-04  6:58 ` [RFC PATCH v5 06/11] trace-cmd: Use splice(2) for vsockets if available Slavomir Kaslev
                   ` (6 subsequent siblings)
  11 siblings, 0 replies; 13+ messages in thread
From: Slavomir Kaslev @ 2019-02-04  6:58 UTC (permalink / raw)
  To: linux-trace-devel; +Cc: rostedt, slavomir.kaslev, tstoyanov, ykaradzhov

This patch adds VM tracing over vsockets. The new `trace-cmd agent` command
needs run on each guest we want to trace:

     you@guest2 # trace-cmd agent

Then `trace-cmd record` on the host can collect data from both the host and
several guests simultaneously:

     you@host $ trace-cmd record -A guest1 -e irq -e sched \
                                 -A guest2 -p function -e all

Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com>
---
 tracecmd/Makefile              |   6 +-
 tracecmd/include/trace-local.h |  16 +
 tracecmd/trace-agent.c         | 225 +++++++++++++
 tracecmd/trace-cmd.c           |   3 +
 tracecmd/trace-msg.c           |   1 +
 tracecmd/trace-record.c        | 594 ++++++++++++++++++++++++++++++---
 tracecmd/trace-usage.c         |  13 +-
 7 files changed, 811 insertions(+), 47 deletions(-)
 create mode 100644 tracecmd/trace-agent.c

diff --git a/tracecmd/Makefile b/tracecmd/Makefile
index 3a11024..865b1c6 100644
--- a/tracecmd/Makefile
+++ b/tracecmd/Makefile
@@ -33,13 +33,17 @@ TRACE_CMD_OBJS += trace-output.o
 TRACE_CMD_OBJS += trace-usage.o
 TRACE_CMD_OBJS += trace-msg.o
 
+ifeq ($(VSOCK_DEFINED), 1)
+TRACE_CMD_OBJS += trace-agent.o
+endif
+
 ALL_OBJS := $(TRACE_CMD_OBJS:%.o=$(bdir)/%.o)
 
 all_objs := $(sort $(ALL_OBJS))
 all_deps := $(all_objs:$(bdir)/%.o=$(bdir)/.%.d)
 
 CONFIG_INCLUDES =
-CONFIG_LIBS	=
+CONFIG_LIBS	= -lrt
 CONFIG_FLAGS	=
 
 all: $(TARGETS)
diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h
index f19c8bb..823d323 100644
--- a/tracecmd/include/trace-local.h
+++ b/tracecmd/include/trace-local.h
@@ -12,6 +12,8 @@
 #include "trace-cmd.h"
 #include "event-utils.h"
 
+#define TRACE_AGENT_DEFAULT_PORT	823
+
 extern int debug;
 extern int quiet;
 
@@ -64,6 +66,8 @@ void trace_split(int argc, char **argv);
 
 void trace_listen(int argc, char **argv);
 
+void trace_agent(int argc, char **argv);
+
 void trace_restore(int argc, char **argv);
 
 void trace_clear(int argc, char **argv);
@@ -88,6 +92,10 @@ void trace_list(int argc, char **argv);
 
 void trace_usage(int argc, char **argv);
 
+int trace_record_agent(struct tracecmd_msg_handle *msg_handle,
+		       int cpus, int *fds,
+		       int argc, char **argv);
+
 struct hook_list;
 
 void trace_init_profile(struct tracecmd_input *handle, struct hook_list *hooks,
@@ -176,6 +184,7 @@ struct buffer_instance {
 	struct func_list	*notrace_funcs;
 
 	const char		*clock;
+	unsigned int		*client_ports;
 
 	struct trace_seq	*s_save;
 	struct trace_seq	*s_print;
@@ -190,6 +199,13 @@ struct buffer_instance {
 	int			tracing_on_fd;
 	int			buffer_size;
 	int			cpu_count;
+
+	int			argc;
+	char			**argv;
+
+	int			cid;
+	int			port;
+	int			*fds;
 };
 
 extern struct buffer_instance top_instance;
diff --git a/tracecmd/trace-agent.c b/tracecmd/trace-agent.c
new file mode 100644
index 0000000..b4b3bbb
--- /dev/null
+++ b/tracecmd/trace-agent.c
@@ -0,0 +1,225 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 VMware Inc, Slavomir Kaslev <kaslevs@vmware.com>
+ *
+ * based on prior implementation by Yoshihiro Yunomae
+ * Copyright (C) 2013 Hitachi, Ltd.
+ * Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <linux/vm_sockets.h>
+
+#include "trace-local.h"
+#include "trace-msg.h"
+
+static int make_vsock(unsigned int port)
+{
+	struct sockaddr_vm addr = {
+		.svm_family = AF_VSOCK,
+		.svm_cid = VMADDR_CID_ANY,
+		.svm_port = port,
+	};
+	int sd;
+
+	sd = socket(AF_VSOCK, SOCK_STREAM, 0);
+	if (sd < 0)
+		return -1;
+
+	setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &(int){1}, sizeof(int));
+
+	if (bind(sd, (struct sockaddr *)&addr, sizeof(addr)))
+		return -1;
+
+	if (listen(sd, SOMAXCONN))
+		return -1;
+
+	return sd;
+}
+
+static int get_vsock_port(int sd, unsigned int *port)
+{
+	struct sockaddr_vm addr;
+	socklen_t addr_len = sizeof(addr);
+
+	if (getsockname(sd, (struct sockaddr *)&addr, &addr_len))
+		return -1;
+
+	if (addr.svm_family != AF_VSOCK)
+		return -1;
+
+	if (port)
+		*port = addr.svm_port;
+
+	return 0;
+}
+
+static void make_vsocks(int nr, int *fds, unsigned int *ports)
+{
+	unsigned int port;
+	int i, fd, ret;
+
+	for (i = 0; i < nr; i++) {
+		fd = make_vsock(VMADDR_PORT_ANY);
+		if (fd < 0)
+			die("Failed to open vsocket");
+
+		ret = get_vsock_port(fd, &port);
+		if (ret < 0)
+			die("Failed to get vsocket address");
+
+		fds[i] = fd;
+		ports[i] = port;
+	}
+}
+
+static void agent_handle(int sd, int nr_cpus, int page_size)
+{
+	struct tracecmd_msg_handle *msg_handle;
+	unsigned int *ports;
+	char **argv = NULL;
+	int argc = 0;
+	int *fds;
+	int ret;
+
+	fds = calloc(nr_cpus, sizeof(*fds));
+	ports = calloc(nr_cpus, sizeof(*ports));
+	if (!fds || !ports)
+		die("Failed to allocate memory");
+
+	msg_handle = tracecmd_msg_handle_alloc(sd, TRACECMD_MSG_FL_CLIENT);
+	if (!msg_handle)
+		die("Failed to allocate message handle");
+
+	ret = tracecmd_msg_recv_trace_req(msg_handle, &argc, &argv);
+	if (ret < 0)
+		die("Failed to receive trace request");
+
+	make_vsocks(nr_cpus, fds, ports);
+
+	ret = tracecmd_msg_send_trace_resp(msg_handle, nr_cpus, page_size, ports);
+	if (ret < 0)
+		die("Failed to send trace response");
+
+	trace_record_agent(msg_handle, nr_cpus, fds, argc, argv);
+
+	free(argv[0]);
+	free(argv);
+	free(ports);
+	free(fds);
+	tracecmd_msg_handle_close(msg_handle);
+	exit(0);
+}
+
+static volatile pid_t handler_pid;
+
+static void handle_sigchld(int sig)
+{
+	int wstatus;
+	pid_t pid;
+
+	for (;;) {
+		pid = waitpid(-1, &wstatus, WNOHANG);
+		if (pid <= 0)
+			break;
+
+		if (pid == handler_pid)
+			handler_pid = 0;
+	}
+}
+
+static void agent_serve(unsigned int port)
+{
+	int sd, cd, nr_cpus;
+	pid_t pid;
+
+	signal(SIGCHLD, handle_sigchld);
+
+	nr_cpus = count_cpus();
+	page_size = getpagesize();
+
+	sd = make_vsock(port);
+	if (sd < 0)
+		die("Failed to open vsocket");
+
+	for (;;) {
+		cd = accept(sd, NULL, NULL);
+		if (cd < 0) {
+			if (errno == EINTR)
+				continue;
+			die("accept");
+		}
+
+		if (handler_pid)
+			goto busy;
+
+		pid = fork();
+		if (pid == 0) {
+			close(sd);
+			signal(SIGCHLD, SIG_DFL);
+			agent_handle(cd, nr_cpus, page_size);
+		}
+		if (pid > 0)
+			handler_pid = pid;
+
+busy:
+		close(cd);
+	}
+}
+
+void trace_agent(int argc, char **argv)
+{
+	bool do_daemon = false;
+	unsigned int port = TRACE_AGENT_DEFAULT_PORT;
+
+	if (argc < 2)
+		usage(argv);
+
+	if (strcmp(argv[1], "agent") != 0)
+		usage(argv);
+
+	for (;;) {
+		int c, option_index = 0;
+		static struct option long_options[] = {
+			{"port", required_argument, NULL, 'p'},
+			{"help", no_argument, NULL, '?'},
+			{NULL, 0, NULL, 0}
+		};
+
+		c = getopt_long(argc-1, argv+1, "+hp:D",
+				long_options, &option_index);
+		if (c == -1)
+			break;
+		switch (c) {
+		case 'h':
+			usage(argv);
+			break;
+		case 'p':
+			port = atoi(optarg);
+			break;
+		case 'D':
+			do_daemon = true;
+			break;
+		default:
+			usage(argv);
+		}
+	}
+
+	if (optind < argc-1)
+		usage(argv);
+
+	if (do_daemon && daemon(1, 0))
+		die("daemon");
+
+	agent_serve(port);
+}
diff --git a/tracecmd/trace-cmd.c b/tracecmd/trace-cmd.c
index 797b303..3ae5e2e 100644
--- a/tracecmd/trace-cmd.c
+++ b/tracecmd/trace-cmd.c
@@ -83,6 +83,9 @@ struct command commands[] = {
 	{"hist", trace_hist},
 	{"mem", trace_mem},
 	{"listen", trace_listen},
+#ifdef VSOCK
+	{"agent", trace_agent},
+#endif
 	{"split", trace_split},
 	{"restore", trace_restore},
 	{"stack", trace_stack},
diff --git a/tracecmd/trace-msg.c b/tracecmd/trace-msg.c
index 8b6fb03..7ffb8a7 100644
--- a/tracecmd/trace-msg.c
+++ b/tracecmd/trace-msg.c
@@ -86,6 +86,7 @@ struct tracecmd_msg_trace_req {
 } __attribute__((packed));
 
 struct tracecmd_msg_trace_resp {
+	be32 flags;
 	be32 cpus;
 	be32 page_size;
 } __attribute__((packed));
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index b911c34..3c28314 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -33,6 +33,9 @@
 #include <errno.h>
 #include <limits.h>
 #include <libgen.h>
+#ifdef VSOCK
+#include <linux/vm_sockets.h>
+#endif
 
 #include "trace-local.h"
 #include "trace-msg.h"
@@ -74,8 +77,6 @@ static int buffers;
 static int clear_function_filters;
 
 static char *host;
-static unsigned int *client_ports;
-static int sfd;
 
 /* Max size to let a per cpu file get */
 static int max_kb;
@@ -518,6 +519,22 @@ static char *get_temp_file(struct buffer_instance *instance, int cpu)
 	return file;
 }
 
+static char *get_guest_file(const char *file, const char *guest)
+{
+	const char *p;
+	char *out = NULL;
+	int base_len;
+
+	p = strrchr(file, '.');
+	if (p && p != file)
+		base_len = p - file;
+	else
+		base_len = strlen(file);
+
+	asprintf(&out, "%.*s-%s%s", base_len, file, guest, file + base_len);
+	return out;
+}
+
 static void put_temp_file(char *file)
 {
 	free(file);
@@ -623,6 +640,18 @@ static void delete_thread_data(void)
 	}
 }
 
+static void tell_guests_to_stop(void)
+{
+	struct buffer_instance *instance;
+
+	for_all_instances(instance) {
+		if (instance->flags & BUFFER_FL_GUEST) {
+			tracecmd_msg_send_close_msg(instance->msg_handle);
+			tracecmd_msg_handle_close(instance->msg_handle);
+		}
+	}
+}
+
 static void stop_threads(enum trace_type type)
 {
 	struct timeval tv = { 0, 0 };
@@ -2571,14 +2600,14 @@ static void flush(int sig)
 		tracecmd_stop_recording(recorder);
 }
 
-static void connect_port(int cpu)
+static int connect_port(const char *host, unsigned int port)
 {
 	struct addrinfo hints;
 	struct addrinfo *results, *rp;
-	int s;
+	int s, sfd;
 	char buf[BUFSIZ];
 
-	snprintf(buf, BUFSIZ, "%u", client_ports[cpu]);
+	snprintf(buf, BUFSIZ, "%u", port);
 
 	memset(&hints, 0, sizeof(hints));
 	hints.ai_family = AF_UNSPEC;
@@ -2605,7 +2634,190 @@ static void connect_port(int cpu)
 
 	freeaddrinfo(results);
 
-	client_ports[cpu] = sfd;
+	return sfd;
+}
+
+#ifdef VSOCK
+static int open_vsock(unsigned int cid, unsigned int port)
+{
+	struct sockaddr_vm addr = {
+		.svm_family = AF_VSOCK,
+		.svm_cid = cid,
+		.svm_port = port,
+	};
+	int sd;
+
+	sd = socket(AF_VSOCK, SOCK_STREAM, 0);
+	if (sd < 0)
+		return -1;
+
+	if (connect(sd, (struct sockaddr *)&addr, sizeof(addr)))
+		return -1;
+
+	return sd;
+}
+#else
+static inline int open_vsock(unsigned int cid, unsigned int port)
+{
+	die("vsock is not supported");
+	return -1;
+}
+#endif
+
+static int do_accept(int sd)
+{
+	int cd;
+
+	for (;;) {
+		cd = accept(sd, NULL, NULL);
+		if (cd < 0) {
+			if (errno == EINTR)
+				continue;
+			die("accept");
+		}
+
+		return cd;
+	}
+
+	return -1;
+}
+
+static bool is_digits(const char *s)
+{
+	const char *p;
+
+	for (p = s; *p; p++)
+		if (!isdigit(*p))
+			return false;
+
+	return true;
+}
+
+struct guest {
+	char *name;
+	int cid;
+	int pid;
+};
+
+static struct guest *guests;
+static size_t guests_len;
+
+static char *get_qemu_guest_name(char *arg)
+{
+	char *tok, *end = arg;
+
+	while ((tok = strsep(&end, ","))) {
+		if (strncmp(tok, "guest=", 6) == 0)
+			return tok + 6;
+	}
+
+	return arg;
+}
+
+static void read_qemu_guests(void)
+{
+	static bool initialized;
+	struct dirent *entry;
+	char path[PATH_MAX];
+	DIR *dir;
+
+	if (initialized)
+		return;
+
+	initialized = true;
+	dir = opendir("/proc");
+	if (!dir)
+		die("opendir");
+
+	for (entry = readdir(dir); entry; entry = readdir(dir)) {
+		bool is_qemu = false, last_was_name = false;
+		struct guest guest = {};
+		char *p, *arg = NULL;
+		size_t arg_size = 0;
+		FILE *f;
+
+		if (!(entry->d_type == DT_DIR && is_digits(entry->d_name)))
+			continue;
+
+		guest.pid = atoi(entry->d_name);
+		snprintf(path, sizeof(path), "/proc/%s/cmdline", entry->d_name);
+		f = fopen(path, "r");
+		if (!f)
+			continue;
+
+		while (getdelim(&arg, &arg_size, 0, f) != -1) {
+			if (!is_qemu && strstr(arg, "qemu-system-")) {
+				is_qemu = true;
+				continue;
+			}
+
+			if (!is_qemu)
+				continue;
+
+			if (strcmp(arg, "-name") == 0) {
+				last_was_name = true;
+				continue;
+			}
+
+			if (last_was_name) {
+				guest.name = strdup(get_qemu_guest_name(arg));
+				last_was_name = false;
+				continue;
+			}
+
+			p = strstr(arg, "guest-cid=");
+			if (p) {
+				guest.cid = atoi(p + 10);
+				continue;
+			}
+		}
+
+		if (!is_qemu)
+			goto next;
+
+		guests = realloc(guests, (guests_len + 1) * sizeof(*guests));
+		if (!guests)
+			die("Can not allocate guest buffer");
+		guests[guests_len++] = guest;
+
+next:
+		free(arg);
+		fclose(f);
+	}
+
+	closedir(dir);
+}
+
+static char *parse_guest_name(char *guest, int *cid, int *port)
+{
+	size_t i;
+	char *p;
+
+	*port = -1;
+	p = strrchr(guest, ':');
+	if (p) {
+		*p = '\0';
+		*port = atoi(p + 1);
+	}
+
+	*cid = -1;
+	p = strrchr(guest, '@');
+	if (p) {
+		*p = '\0';
+		*cid = atoi(p + 1);
+	} else if (is_digits(guest))
+		*cid = atoi(guest);
+
+	read_qemu_guests();
+	for (i = 0; i < guests_len; i++) {
+		if ((*cid > 0 && *cid == guests[i].cid) ||
+		    strcmp(guest, guests[i].name) == 0) {
+			*cid = guests[i].cid;
+			return guests[i].name;
+		}
+	}
+
+	return guest;
 }
 
 static void set_prio(int prio)
@@ -2652,6 +2864,17 @@ create_recorder_instance(struct buffer_instance *instance, const char *file, int
 	struct tracecmd_recorder *record;
 	char *path;
 
+	if (instance->flags & BUFFER_FL_GUEST) {
+		int sd;
+
+		sd = open_vsock(instance->cid, instance->client_ports[cpu]);
+		if (sd < 0)
+			die("Failed to connect to agent");
+
+		return tracecmd_create_recorder_virt(
+			file, cpu, recorder_flags | TRACECMD_RECORD_NOSPLICE, sd);
+	}
+
 	if (brass)
 		return create_recorder_instance_pipe(instance, cpu, brass);
 
@@ -2676,7 +2899,7 @@ static int create_recorder(struct buffer_instance *instance, int cpu,
 {
 	long ret;
 	char *file;
-	int pid;
+	pid_t pid;
 
 	if (type != TRACE_TYPE_EXTRACT) {
 		signal(SIGUSR1, flush);
@@ -2695,19 +2918,24 @@ static int create_recorder(struct buffer_instance *instance, int cpu,
 		instance->cpu_count = 0;
 	}
 
-	if (client_ports) {
-		char *path;
+	if ((instance->client_ports && !(instance->flags & BUFFER_FL_GUEST)) ||
+	    (instance->flags & BUFFER_FL_AGENT)) {
+		unsigned int flags = recorder_flags;
+		char *path = NULL;
+		int fd;
 
-		connect_port(cpu);
-		if (instance->name)
+		if (instance->flags & BUFFER_FL_AGENT)
+			fd = do_accept(instance->fds[cpu]);
+		else
+			fd = connect_port(host, instance->client_ports[cpu]);
+		if (fd < 0)
+			die("Failed connecting to client");
+		if (instance->name && !(instance->flags & BUFFER_FL_AGENT))
 			path = get_instance_dir(instance);
 		else
 			path = tracecmd_find_tracing_dir();
-		recorder = tracecmd_create_buffer_recorder_fd(client_ports[cpu],
-							      cpu, recorder_flags,
-							      path);
-		if (instance->name)
-			tracecmd_put_tracing_file(path);
+		recorder = tracecmd_create_buffer_recorder_fd(fd, cpu, flags, path);
+		tracecmd_put_tracing_file(path);
 	} else {
 		file = get_temp_file(instance, cpu);
 		recorder = create_recorder_instance(instance, file, cpu, brass);
@@ -2745,7 +2973,8 @@ static void check_first_msg_from_server(struct tracecmd_msg_handle *msg_handle)
 		die("server not tracecmd server");
 }
 
-static void communicate_with_listener_v1(struct tracecmd_msg_handle *msg_handle)
+static void communicate_with_listener_v1(struct tracecmd_msg_handle *msg_handle,
+					 unsigned int **client_ports)
 {
 	char buf[BUFSIZ];
 	ssize_t n;
@@ -2788,8 +3017,8 @@ static void communicate_with_listener_v1(struct tracecmd_msg_handle *msg_handle)
 		/* No options */
 		write(msg_handle->fd, "0", 2);
 
-	client_ports = malloc(local_cpu_count * sizeof(*client_ports));
-	if (!client_ports)
+	*client_ports = malloc(local_cpu_count * sizeof(*client_ports));
+	if (!*client_ports)
 		die("Failed to allocate client ports for %d cpus", local_cpu_count);
 
 	/*
@@ -2807,13 +3036,14 @@ static void communicate_with_listener_v1(struct tracecmd_msg_handle *msg_handle)
 		if (i == BUFSIZ)
 			die("read bad port number");
 		buf[i] = 0;
-		client_ports[cpu] = atoi(buf);
+		(*client_ports)[cpu] = atoi(buf);
 	}
 }
 
-static void communicate_with_listener_v3(struct tracecmd_msg_handle *msg_handle)
+static void communicate_with_listener_v3(struct tracecmd_msg_handle *msg_handle,
+					 unsigned int **client_ports)
 {
-	if (tracecmd_msg_send_init_data(msg_handle, &client_ports) < 0)
+	if (tracecmd_msg_send_init_data(msg_handle, client_ports) < 0)
 		die("Cannot communicate with server");
 }
 
@@ -2864,7 +3094,7 @@ static void check_protocol_version(struct tracecmd_msg_handle *msg_handle)
 	}
 }
 
-static struct tracecmd_msg_handle *setup_network(void)
+static struct tracecmd_msg_handle *setup_network(struct buffer_instance *instance)
 {
 	struct tracecmd_msg_handle *msg_handle = NULL;
 	struct addrinfo hints;
@@ -2934,11 +3164,11 @@ again:
 			close(sfd);
 			goto again;
 		}
-		communicate_with_listener_v3(msg_handle);
+		communicate_with_listener_v3(msg_handle, &instance->client_ports);
 	}
 
 	if (msg_handle->version == V1_PROTOCOL)
-		communicate_with_listener_v1(msg_handle);
+		communicate_with_listener_v1(msg_handle, &instance->client_ports);
 
 	return msg_handle;
 }
@@ -2951,7 +3181,7 @@ setup_connection(struct buffer_instance *instance, struct common_record_context
 	struct tracecmd_msg_handle *msg_handle;
 	struct tracecmd_output *network_handle;
 
-	msg_handle = setup_network();
+	msg_handle = setup_network(instance);
 
 	/* Now create the handle through this socket */
 	if (msg_handle->version == V3_PROTOCOL) {
@@ -2978,28 +3208,99 @@ static void finish_network(struct tracecmd_msg_handle *msg_handle)
 	free(host);
 }
 
+static void connect_to_agent(struct buffer_instance *instance)
+{
+	struct tracecmd_msg_handle *msg_handle;
+	int sd, ret, nr_cpus, page_size;
+	unsigned int *ports;
+
+	sd = open_vsock(instance->cid, instance->port);
+	if (sd < 0)
+		die("Failed to connect to vsocket @%d:%d",
+		    instance->cid, instance->port);
+
+	msg_handle = tracecmd_msg_handle_alloc(sd, TRACECMD_MSG_FL_CLIENT);
+	if (!msg_handle)
+		die("Failed to allocate message handle");
+
+	ret = tracecmd_msg_send_trace_req(msg_handle, instance->argc, instance->argv);
+	if (ret < 0)
+		die("Failed to send trace request");
+
+	ret = tracecmd_msg_recv_trace_resp(msg_handle, &nr_cpus, &page_size, &ports);
+	if (ret < 0)
+		die("Failed to receive trace response");
+
+	instance->client_ports = ports;
+	instance->cpu_count = nr_cpus;
+
+	/* the msg_handle now points to the guest fd */
+	instance->msg_handle = msg_handle;
+}
+
+static void setup_guest(struct buffer_instance *instance)
+{
+	struct tracecmd_msg_handle *msg_handle = instance->msg_handle;
+	char *file;
+	int fd;
+
+	/* Create a place to store the guest meta data */
+	file = get_guest_file(output_file, instance->name);
+	if (!file)
+		die("Failed to allocate memory");
+
+	fd = open(file, O_CREAT|O_WRONLY|O_TRUNC, 0644);
+	put_temp_file(file);
+	if (fd < 0)
+		die("Failed to open", file);
+
+	/* Start reading tracing metadata */
+	if (tracecmd_msg_read_data(msg_handle, fd))
+		die("Failed receiving metadata");
+	close(fd);
+}
+
+static void setup_agent(struct buffer_instance *instance, struct common_record_context *ctx)
+{
+	struct tracecmd_output *network_handle;
+
+	network_handle = tracecmd_create_init_fd_msg(instance->msg_handle,
+						     listed_events);
+	add_options(network_handle, ctx);
+	tracecmd_write_cpus(network_handle, instance->cpu_count);
+	tracecmd_write_options(network_handle);
+	tracecmd_msg_finish_sending_data(instance->msg_handle);
+	instance->network_handle = network_handle;
+}
+
 void start_threads(enum trace_type type, struct common_record_context *ctx)
 {
 	struct buffer_instance *instance;
-	int *brass = NULL;
 	int total_cpu_count = 0;
 	int i = 0;
 	int ret;
 
-	for_all_instances(instance)
+	for_all_instances(instance) {
+		/* Start the connection now to find out how many CPUs we need */
+		if (instance->flags & BUFFER_FL_GUEST)
+			connect_to_agent(instance);
 		total_cpu_count += instance->cpu_count;
+	}
 
 	/* make a thread for every CPU we have */
-	pids = malloc(sizeof(*pids) * total_cpu_count * (buffers + 1));
+	pids = calloc(total_cpu_count * (buffers + 1), sizeof(*pids));
 	if (!pids)
-		die("Failed to allocat pids for %d cpus", total_cpu_count);
-
-	memset(pids, 0, sizeof(*pids) * total_cpu_count * (buffers + 1));
+		die("Failed to allocate pids for %d cpus", total_cpu_count);
 
 	for_all_instances(instance) {
+		int *brass = NULL;
 		int x, pid;
 
-		if (host) {
+		if (instance->flags & BUFFER_FL_AGENT) {
+			setup_agent(instance, ctx);
+		} else if (instance->flags & BUFFER_FL_GUEST) {
+			setup_guest(instance);
+		} else if (host) {
 			instance->msg_handle = setup_connection(instance, ctx);
 			if (!instance->msg_handle)
 				die("Failed to make connection");
@@ -3139,13 +3440,14 @@ static void print_stat(struct buffer_instance *instance)
 {
 	int cpu;
 
+	if (quiet)
+		return;
+
 	if (!is_top_instance(instance))
-		if (!quiet)
-			printf("\nBuffer: %s\n\n", instance->name);
+		printf("\nBuffer: %s\n\n", instance->name);
 
 	for (cpu = 0; cpu < instance->cpu_count; cpu++)
-		if (!quiet)
-			trace_seq_do_printf(&instance->s_print[cpu]);
+		trace_seq_do_printf(&instance->s_print[cpu]);
 }
 
 enum {
@@ -3171,7 +3473,44 @@ static void add_options(struct tracecmd_output *handle, struct common_record_con
 	tracecmd_add_option(handle, TRACECMD_OPTION_TRACECLOCK, 0, NULL);
 	add_option_hooks(handle);
 	add_uname(handle);
+}
+
+static void write_guest_file(struct buffer_instance *instance)
+{
+	struct tracecmd_output *handle;
+	int cpu_count = instance->cpu_count;
+	char *file;
+	char **temp_files;
+	int i, fd;
+
+	file = get_guest_file(output_file, instance->name);
+	fd = open(file, O_RDWR);
+	if (fd < 0)
+		die("error opening %s", file);
+	put_temp_file(file);
+
+	handle = tracecmd_get_output_handle_fd(fd);
+	if (!handle)
+		die("error writing to %s", file);
 
+	temp_files = malloc(sizeof(*temp_files) * cpu_count);
+	if (!temp_files)
+		die("failed to allocate temp_files for %d cpus",
+		    cpu_count);
+
+	for (i = 0; i < cpu_count; i++) {
+		temp_files[i] = get_temp_file(instance, i);
+		if (!temp_files[i])
+			die("failed to allocate memory");
+	}
+
+	if (tracecmd_write_cpu_data(handle, cpu_count, temp_files) < 0)
+		die("failed to write CPU data");
+	tracecmd_output_close(handle);
+
+	for (i = 0; i < cpu_count; i++)
+		put_temp_file(temp_files[i]);
+	free(temp_files);
 }
 
 static void record_data(struct common_record_context *ctx)
@@ -3185,7 +3524,9 @@ static void record_data(struct common_record_context *ctx)
 	int i;
 
 	for_all_instances(instance) {
-		if (instance->msg_handle)
+		if (instance->flags & BUFFER_FL_GUEST)
+			write_guest_file(instance);
+		else if (host && instance->msg_handle)
 			finish_network(instance->msg_handle);
 		else
 			local = true;
@@ -4404,6 +4745,7 @@ void trace_stop(int argc, char **argv)
 		c = getopt(argc-1, argv+1, "hatB:");
 		if (c == -1)
 			break;
+
 		switch (c) {
 		case 'h':
 			usage(argv);
@@ -4566,6 +4908,63 @@ static void init_common_record_context(struct common_record_context *ctx,
 #define IS_STREAM(ctx) ((ctx)->curr_cmd == CMD_stream)
 #define IS_PROFILE(ctx) ((ctx)->curr_cmd == CMD_profile)
 #define IS_RECORD(ctx) ((ctx)->curr_cmd == CMD_record)
+#define IS_AGENT(ctx) ((ctx)->curr_cmd == CMD_record_agent)
+
+static void add_argv(struct buffer_instance *instance, char *arg, bool prepend)
+{
+	instance->argv = realloc(instance->argv,
+				 (instance->argc + 1) * sizeof(char *));
+	if (!instance->argv)
+		die("Can not allocate instance args");
+	if (prepend) {
+		memmove(instance->argv + 1, instance->argv,
+			instance->argc * sizeof(*instance->argv));
+		instance->argv[0] = arg;
+	} else {
+		instance->argv[instance->argc] = arg;
+	}
+	instance->argc++;
+}
+
+static void add_arg(struct buffer_instance *instance,
+		    int c, const char *opts,
+		    struct option *long_options, char *optarg)
+{
+	char *ptr;
+	char *arg;
+	int ret;
+	int i;
+
+	/* Short or long arg */
+	if (!(c & 0x80)) {
+		ret = asprintf(&arg, "-%c", c);
+		if (ret < 0)
+			die("Can not allocate argument");
+		ptr = strstr(opts, arg+1);
+		if (!ptr)
+			return; /* Not found? */
+		add_argv(instance, arg, false);
+		if (ptr[1] == ':')
+			add_argv(instance, optarg, false);
+		return;
+	}
+	for (i = 0; long_options[i].name; i++) {
+		if (c == long_options[i].val) {
+			ret = asprintf(&arg, "--%s", long_options[i].name);
+			if (ret < 0)
+				die("Can not allocate argument");
+			add_argv(instance, arg, false);
+			if (long_options[i].has_arg) {
+				arg = strdup(optarg);
+				if (!arg)
+					die("Can not allocate arguments");
+				add_argv(instance, arg, false);
+				return;
+			}
+		}
+	}
+	/* Not found? */
+}
 
 static void parse_record_options(int argc,
 				 char **argv,
@@ -4607,10 +5006,20 @@ static void parse_record_options(int argc,
 		if (IS_EXTRACT(ctx))
 			opts = "+haf:Fp:co:O:sr:g:l:n:P:N:tb:B:ksiT";
 		else
-			opts = "+hae:f:Fp:cC:dDGo:O:s:r:vg:l:n:P:N:tb:R:B:ksSiTm:M:H:q";
+			opts = "+hae:f:FA:p:cC:dDGo:O:s:r:vg:l:n:P:N:tb:R:B:ksSiTm:M:H:q";
 		c = getopt_long (argc-1, argv+1, opts, long_options, &option_index);
 		if (c == -1)
 			break;
+
+		/*
+		 * If the current instance is to record a guest, then save
+		 * all the arguments for this instance.
+		 */
+		if (c != 'B' && c != 'A' && ctx->instance->flags & BUFFER_FL_GUEST) {
+			add_arg(ctx->instance, c, opts, long_options, optarg);
+			continue;
+		}
+
 		switch (c) {
 		case 'h':
 			usage(argv);
@@ -4663,6 +5072,26 @@ static void parse_record_options(int argc,
 			add_trigger(event, optarg);
 			break;
 
+		case 'A': {
+			char *name = NULL;
+			int cid = -1, port = -1;
+
+			if (!IS_RECORD(ctx))
+				die("-A is only allowed for record operations");
+
+			name = parse_guest_name(optarg, &cid, &port);
+			if (!name || cid == -1)
+				die("guest %s not found", optarg);
+			if (port == -1)
+				port = TRACE_AGENT_DEFAULT_PORT;
+
+			ctx->instance = create_instance(name);
+			ctx->instance->flags |= BUFFER_FL_GUEST;
+			ctx->instance->cid = cid;
+			ctx->instance->port = port;
+			add_instance(ctx->instance, 0);
+			break;
+		}
 		case 'F':
 			test_set_event_pid();
 			filter_task = 1;
@@ -4733,6 +5162,8 @@ static void parse_record_options(int argc,
 			ctx->disable = 1;
 			break;
 		case 'o':
+			if (IS_AGENT(ctx))
+				die("-o incompatible with agent recording");
 			if (host)
 				die("-o incompatible with -N");
 			if (IS_START(ctx))
@@ -4794,6 +5225,8 @@ static void parse_record_options(int argc,
 		case 'N':
 			if (!IS_RECORD(ctx))
 				die("-N only available with record");
+			if (IS_AGENT(ctx))
+				die("-N incompatible with agent recording");
 			if (ctx->output)
 				die("-N incompatible with -o");
 			host = optarg;
@@ -4890,6 +5323,16 @@ static void parse_record_options(int argc,
 		}
 	}
 
+	/* If --date is specified, prepend it to all guest VM flags */
+	if (ctx->date) {
+		struct buffer_instance *instance;
+
+		for_all_instances(instance) {
+			if (instance->flags & BUFFER_FL_GUEST)
+				add_argv(instance, "--date", true);
+		}
+	}
+
 	if (!ctx->filtered && ctx->instance->filter_mod)
 		add_func(&ctx->instance->filter_funcs,
 			 ctx->instance->filter_mod, "*");
@@ -4920,7 +5363,8 @@ static enum trace_type get_trace_cmd_type(enum trace_cmd cmd)
 		{CMD_stream, TRACE_TYPE_STREAM},
 		{CMD_extract, TRACE_TYPE_EXTRACT},
 		{CMD_profile, TRACE_TYPE_STREAM},
-		{CMD_start, TRACE_TYPE_START}
+		{CMD_start, TRACE_TYPE_START},
+		{CMD_record_agent, TRACE_TYPE_RECORD}
 	};
 
 	for (int i = 0; i < ARRAY_SIZE(trace_type_per_command); i++) {
@@ -4952,12 +5396,28 @@ static void finalize_record_trace(struct common_record_context *ctx)
 		if (instance->flags & BUFFER_FL_KEEP)
 			write_tracing_on(instance,
 					 instance->tracing_on_init_val);
+		if (instance->flags & BUFFER_FL_AGENT)
+			tracecmd_output_close(instance->network_handle);
 	}
 
 	if (host)
 		tracecmd_output_close(ctx->instance->network_handle);
 }
 
+static bool has_local_instances(void)
+{
+	struct buffer_instance *instance;
+
+	for_all_instances(instance) {
+		if (instance->flags & BUFFER_FL_GUEST)
+			continue;
+		if (host && instance->msg_handle)
+			continue;
+		return true;
+	}
+	return false;
+}
+
 /*
  * This function contains common code for the following commands:
  * record, start, stream, profile.
@@ -4986,7 +5446,6 @@ static void record_trace(int argc, char **argv,
 
 	/* Save the state of tracing_on before starting */
 	for_all_instances(instance) {
-
 		if (!ctx->manual && instance->flags & BUFFER_FL_PROFILE)
 			enable_profile(instance);
 
@@ -5003,14 +5462,16 @@ static void record_trace(int argc, char **argv,
 
 	page_size = getpagesize();
 
-	fset = set_ftrace(!ctx->disable, ctx->total_disable);
+	if (!(ctx->instance->flags & BUFFER_FL_GUEST))
+		fset = set_ftrace(!ctx->disable, ctx->total_disable);
 	tracecmd_disable_all_tracing(1);
 
 	for_all_instances(instance)
 		set_clock(instance);
 
 	/* Record records the date first */
-	if (IS_RECORD(ctx) && ctx->date)
+	if (ctx->date &&
+	    ((IS_RECORD(ctx) && has_local_instances()) || IS_AGENT(ctx)))
 		ctx->date2ts = get_date_to_ts();
 
 	for_all_instances(instance) {
@@ -5045,9 +5506,13 @@ static void record_trace(int argc, char **argv,
 		exit(0);
 	}
 
-	if (ctx->run_command)
+	if (ctx->run_command) {
 		run_cmd(type, (argc - optind) - 1, &argv[optind + 1]);
-	else {
+	} else if (ctx->instance && (ctx->instance->flags & BUFFER_FL_AGENT)) {
+		update_task_filter();
+		tracecmd_enable_tracing();
+		tracecmd_msg_wait_close(ctx->instance->msg_handle);
+	} else {
 		update_task_filter();
 		tracecmd_enable_tracing();
 		/* We don't ptrace ourself */
@@ -5057,6 +5522,8 @@ static void record_trace(int argc, char **argv,
 		printf("Hit Ctrl^C to stop recording\n");
 		while (!finished)
 			trace_or_sleep(type);
+
+		tell_guests_to_stop();
 	}
 
 	tracecmd_disable_tracing();
@@ -5202,3 +5669,40 @@ void trace_record(int argc, char **argv)
 	record_trace(argc, argv, &ctx);
 	exit(0);
 }
+
+int trace_record_agent(struct tracecmd_msg_handle *msg_handle,
+		       int cpus, int *fds,
+		       int argc, char **argv)
+{
+	struct common_record_context ctx;
+	char **argv_plus;
+
+	/* Reset optind for getopt_long */
+	optind = 1;
+	/*
+	 * argc is the number of elements in argv, but we need to convert
+	 * argc and argv into "trace-cmd", "record", argv.
+	 * where argc needs to grow by two.
+	 */
+	argv_plus = calloc(argc + 2, sizeof(char *));
+	if (!argv_plus)
+		return -ENOMEM;
+
+	argv_plus[0] = "trace-cmd";
+	argv_plus[1] = "record";
+	memmove(argv_plus + 2, argv, argc * sizeof(char *));
+	argc += 2;
+
+	parse_record_options(argc, argv_plus, CMD_record_agent, &ctx);
+	if (ctx.run_command)
+		return -EINVAL;
+
+	ctx.instance->fds = fds;
+	ctx.instance->flags |= BUFFER_FL_AGENT;
+	ctx.instance->msg_handle = msg_handle;
+	msg_handle->version = V3_PROTOCOL;
+	record_trace(argc, argv, &ctx);
+
+	free(argv_plus);
+	return 0;
+}
diff --git a/tracecmd/trace-usage.c b/tracecmd/trace-usage.c
index 9ea1906..e845f50 100644
--- a/tracecmd/trace-usage.c
+++ b/tracecmd/trace-usage.c
@@ -231,11 +231,22 @@ static struct usage_help usage_help[] = {
 		"listen on a network socket for trace clients",
 		" %s listen -p port[-D][-o file][-d dir][-l logfile]\n"
 		"          Creates a socket to listen for clients.\n"
-		"          -D create it in daemon mode.\n"
+		"          -p port number to listen on.\n"
+		"          -D run in daemon mode.\n"
 		"          -o file name to use for clients.\n"
 		"          -d directory to store client files.\n"
 		"          -l logfile to write messages to.\n"
 	},
+#ifdef VSOCK
+	{
+		"agent",
+		"listen on a vsocket for trace clients",
+		" %s agent -p port[-D]\n"
+		"          Creates a vsocket to listen for clients.\n"
+		"          -p port number to listen on.\n"
+		"          -D run in daemon mode.\n"
+	},
+#endif
 	{
 		"list",
 		"list the available events, plugins or options",
-- 
2.19.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [RFC PATCH v5 06/11] trace-cmd: Use splice(2) for vsockets if available
  2019-02-04  6:58 [RFC PATCH v5 00/11] Add VM kernel tracing over vsockets and FIFOs Slavomir Kaslev
                   ` (4 preceding siblings ...)
  2019-02-04  6:58 ` [RFC PATCH v5 05/11] trace-cmd: Add VM kernel tracing over vsockets transport Slavomir Kaslev
@ 2019-02-04  6:58 ` Slavomir Kaslev
  2019-02-04  6:58 ` [RFC PATCH v5 07/11] trace-cmd: Add `trace-cmd setup-guest` command Slavomir Kaslev
                   ` (5 subsequent siblings)
  11 siblings, 0 replies; 13+ messages in thread
From: Slavomir Kaslev @ 2019-02-04  6:58 UTC (permalink / raw)
  To: linux-trace-devel; +Cc: rostedt, slavomir.kaslev, tstoyanov, ykaradzhov

Detect if splice(2) reading is supported for vsockets (Linux 4.20 and
later) and use it, or fallback to read/write-ing otherwise.

Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com>
---
 lib/trace-cmd/trace-recorder.c |  6 ++--
 tracecmd/trace-record.c        | 56 ++++++++++++++++++++++++++++++++--
 2 files changed, 56 insertions(+), 6 deletions(-)

diff --git a/lib/trace-cmd/trace-recorder.c b/lib/trace-cmd/trace-recorder.c
index 83a12f4..b750935 100644
--- a/lib/trace-cmd/trace-recorder.c
+++ b/lib/trace-cmd/trace-recorder.c
@@ -380,10 +380,8 @@ static long splice_data(struct tracecmd_recorder *recorder)
 	ret = splice(recorder->brass[0], NULL, recorder->fd, NULL,
 		     read, recorder->fd_flags);
 	if (ret < 0) {
-		if (errno != EAGAIN && errno != EINTR) {
-			warning("recorder error in splice output");
-			return -1;
-		}
+		if (errno != EAGAIN && errno != EINTR)
+			return ret;
 		return total_read;
 	} else
 		update_fd(recorder, ret);
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index 3c28314..71176d9 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -2656,12 +2656,61 @@ static int open_vsock(unsigned int cid, unsigned int port)
 
 	return sd;
 }
+
+static int try_splice_read_vsock(void)
+{
+	int ret, sd, brass[2];
+
+	sd = socket(AF_VSOCK, SOCK_STREAM, 0);
+	if (sd < 0)
+		return sd;
+
+	ret = pipe(brass);
+	if (ret < 0)
+		goto out_close_sd;
+
+	/*
+	 * On kernels that don't support splice reading from vsockets
+	 * this will fail with EINVAL, or ENOTCONN otherwise.
+	 * Technically, it should never succeed but if it does, claim splice
+	 * reading is supported.
+	 */
+	ret = splice(sd, NULL, brass[1], NULL, 10, 0);
+	if (ret < 0)
+		ret = errno != EINVAL;
+	else
+		ret = 1;
+
+	close(brass[0]);
+	close(brass[1]);
+out_close_sd:
+	close(sd);
+	return ret;
+}
+
+static bool can_splice_read_vsock(void)
+{
+	static bool initialized, res;
+
+	if (initialized)
+		return res;
+
+	res = try_splice_read_vsock() > 0;
+	initialized = true;
+	return res;
+}
+
 #else
 static inline int open_vsock(unsigned int cid, unsigned int port)
 {
 	die("vsock is not supported");
 	return -1;
 }
+
+static bool can_splice_read_vsock(void)
+{
+	return false;
+}
 #endif
 
 static int do_accept(int sd)
@@ -2866,13 +2915,16 @@ create_recorder_instance(struct buffer_instance *instance, const char *file, int
 
 	if (instance->flags & BUFFER_FL_GUEST) {
 		int sd;
+		unsigned int flags;
 
 		sd = open_vsock(instance->cid, instance->client_ports[cpu]);
 		if (sd < 0)
 			die("Failed to connect to agent");
 
-		return tracecmd_create_recorder_virt(
-			file, cpu, recorder_flags | TRACECMD_RECORD_NOSPLICE, sd);
+		flags = recorder_flags;
+		if (!can_splice_read_vsock())
+			flags |= TRACECMD_RECORD_NOSPLICE;
+		return tracecmd_create_recorder_virt(file, cpu, flags, sd);
 	}
 
 	if (brass)
-- 
2.19.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [RFC PATCH v5 07/11] trace-cmd: Add `trace-cmd setup-guest` command
  2019-02-04  6:58 [RFC PATCH v5 00/11] Add VM kernel tracing over vsockets and FIFOs Slavomir Kaslev
                   ` (5 preceding siblings ...)
  2019-02-04  6:58 ` [RFC PATCH v5 06/11] trace-cmd: Use splice(2) for vsockets if available Slavomir Kaslev
@ 2019-02-04  6:58 ` Slavomir Kaslev
  2019-02-04  6:58 ` [RFC PATCH v5 08/11] trace-cmd: Try to autodetect number of guest CPUs in setup-guest if not specified Slavomir Kaslev
                   ` (4 subsequent siblings)
  11 siblings, 0 replies; 13+ messages in thread
From: Slavomir Kaslev @ 2019-02-04  6:58 UTC (permalink / raw)
  To: linux-trace-devel; +Cc: rostedt, slavomir.kaslev, tstoyanov, ykaradzhov

Add `trace-cmd setup-guest` command that creates the necessary FIFOs for tracing
a guest over FIFOs instead of vsockets.

Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com>
---
 tracecmd/Makefile              |   1 +
 tracecmd/include/trace-local.h |   6 ++
 tracecmd/trace-cmd.c           |   1 +
 tracecmd/trace-setup-guest.c   | 181 +++++++++++++++++++++++++++++++++
 tracecmd/trace-usage.c         |   8 ++
 5 files changed, 197 insertions(+)
 create mode 100644 tracecmd/trace-setup-guest.c

diff --git a/tracecmd/Makefile b/tracecmd/Makefile
index 865b1c6..d3e3080 100644
--- a/tracecmd/Makefile
+++ b/tracecmd/Makefile
@@ -35,6 +35,7 @@ TRACE_CMD_OBJS += trace-msg.o
 
 ifeq ($(VSOCK_DEFINED), 1)
 TRACE_CMD_OBJS += trace-agent.o
+TRACE_CMD_OBJS += trace-setup-guest.o
 endif
 
 ALL_OBJS := $(TRACE_CMD_OBJS:%.o=$(bdir)/%.o)
diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h
index 823d323..b23130e 100644
--- a/tracecmd/include/trace-local.h
+++ b/tracecmd/include/trace-local.h
@@ -14,6 +14,10 @@
 
 #define TRACE_AGENT_DEFAULT_PORT	823
 
+#define GUEST_PIPE_NAME		"trace-pipe-cpu"
+#define GUEST_DIR_FMT		"/var/lib/trace-cmd/virt/%s"
+#define GUEST_FIFO_FMT		GUEST_DIR_FMT "/" GUEST_PIPE_NAME "%d"
+
 extern int debug;
 extern int quiet;
 
@@ -68,6 +72,8 @@ void trace_listen(int argc, char **argv);
 
 void trace_agent(int argc, char **argv);
 
+void trace_setup_guest(int argc, char **argv);
+
 void trace_restore(int argc, char **argv);
 
 void trace_clear(int argc, char **argv);
diff --git a/tracecmd/trace-cmd.c b/tracecmd/trace-cmd.c
index 3ae5e2e..4da82b4 100644
--- a/tracecmd/trace-cmd.c
+++ b/tracecmd/trace-cmd.c
@@ -85,6 +85,7 @@ struct command commands[] = {
 	{"listen", trace_listen},
 #ifdef VSOCK
 	{"agent", trace_agent},
+	{"setup-guest", trace_setup_guest},
 #endif
 	{"split", trace_split},
 	{"restore", trace_restore},
diff --git a/tracecmd/trace-setup-guest.c b/tracecmd/trace-setup-guest.c
new file mode 100644
index 0000000..1a2c8d4
--- /dev/null
+++ b/tracecmd/trace-setup-guest.c
@@ -0,0 +1,181 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 VMware Inc, Slavomir Kaslev <kaslevs@vmware.com>
+ *
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <grp.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "trace-local.h"
+#include "trace-msg.h"
+
+static int make_dir(const char *path, mode_t mode)
+{
+	char *buf, *end, *p;
+	int ret = 0;
+
+	buf = strdup(path);
+	end = buf + strlen(buf);
+
+	for (p = buf; p < end; p++) {
+		for (; p < end && *p == '/'; p++);
+		for (; p < end && *p != '/'; p++);
+
+		*p = '\0';
+		ret = mkdir(buf, mode);
+		if (ret < 0) {
+			if (errno != EEXIST)
+				break;
+			ret = 0;
+		}
+		*p = '/';
+	}
+
+	free(buf);
+	return ret;
+}
+
+static int make_fifo(const char *path, mode_t mode)
+{
+	struct stat st;
+	int ret;
+
+	ret = stat(path, &st);
+	if (ret == 0) {
+		if (S_ISFIFO(st.st_mode))
+			return 0;
+		errno = EEXIST;
+		return -1;
+	}
+
+	return mkfifo(path, mode);
+}
+
+static int make_guest_dir(const char *guest)
+{
+	char path[PATH_MAX];
+
+	snprintf(path, sizeof(path), GUEST_DIR_FMT, guest);
+	return make_dir(path, 0750);
+}
+
+static int make_guest_fifo(const char *guest, int cpu, mode_t mode)
+{
+	static const char *exts[] = {".in", ".out"};
+	char path[PATH_MAX];
+	int i, ret = 0;
+
+	for (i = 0; i < ARRAY_SIZE(exts); i++) {
+		snprintf(path, sizeof(path), GUEST_FIFO_FMT "%s",
+			 guest, cpu, exts[i]);
+		ret = make_fifo(path, mode);
+		if (ret < 0)
+			break;
+	}
+
+	return ret;
+}
+
+static int make_guest_fifos(const char *guest, int nr_cpus, mode_t mode)
+{
+	int i, ret = 0;
+	mode_t mask;
+
+	mask = umask(0);
+	for (i = 0; i < nr_cpus; i++) {
+		ret = make_guest_fifo(guest, i, mode);
+		if (ret < 0)
+			break;
+	}
+	umask(mask);
+
+	return ret;
+}
+
+static void do_setup_guest(const char *guest, int nr_cpus, mode_t mode, gid_t gid)
+{
+	gid_t save_egid;
+	int ret;
+
+	save_egid = getegid();
+	ret = setegid(gid);
+	if (ret < 0)
+		pdie("failed to set effective group ID");
+
+	ret = make_guest_dir(guest);
+	if (ret < 0)
+		pdie("failed to create guest directory for %s", guest);
+
+	ret = make_guest_fifos(guest, nr_cpus, mode);
+	if (ret < 0)
+		pdie("failed to create FIFOs for %s", guest);
+
+	ret = setegid(save_egid);
+	if (ret < 0)
+		pdie("failed to restore effective group ID");
+}
+
+void trace_setup_guest(int argc, char **argv)
+{
+	struct group *group;
+	mode_t mode = 0660;
+	int nr_cpus = -1;
+	gid_t gid = -1;
+	char *guest;
+
+	if (argc < 2)
+		usage(argv);
+
+	if (strcmp(argv[1], "setup-guest") != 0)
+		usage(argv);
+
+	for (;;) {
+		int c, option_index = 0;
+		static struct option long_options[] = {
+			{"help", no_argument, NULL, '?'},
+			{NULL, 0, NULL, 0}
+		};
+
+		c = getopt_long(argc-1, argv+1, "+hc:p:g:",
+				long_options, &option_index);
+		if (c == -1)
+			break;
+		switch (c) {
+		case 'h':
+			usage(argv);
+			break;
+		case 'c':
+			nr_cpus = atoi(optarg);
+			break;
+		case 'p':
+			mode = strtol(optarg, NULL, 8);
+			break;
+		case 'g':
+			group = getgrnam(optarg);
+			if (!group)
+				pdie("group %s does not exist", optarg);
+			gid = group->gr_gid;
+			break;
+		default:
+			usage(argv);
+		}
+	}
+
+	if (optind != argc-2)
+		usage(argv);
+
+	guest = argv[optind+1];
+
+	if (nr_cpus <= 0)
+		pdie("invalid number of cpus for guest %s", guest);
+
+	do_setup_guest(guest, nr_cpus, mode, gid);
+}
diff --git a/tracecmd/trace-usage.c b/tracecmd/trace-usage.c
index e845f50..7a8002f 100644
--- a/tracecmd/trace-usage.c
+++ b/tracecmd/trace-usage.c
@@ -246,6 +246,14 @@ static struct usage_help usage_help[] = {
 		"          -p port number to listen on.\n"
 		"          -D run in daemon mode.\n"
 	},
+	{
+		"setup-guest",
+		"create FIFOs for tracing guest VMs",
+		" %s setup-guest -c cpus[-p perm][-g group] guest\n"
+		"          -c number of guest virtual CPUs\n"
+		"          -p FIFOs permissions (default: 0660)\n"
+		"          -g FIFOs group owner\n"
+	},
 #endif
 	{
 		"list",
-- 
2.19.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [RFC PATCH v5 08/11] trace-cmd: Try to autodetect number of guest CPUs in setup-guest if not specified
  2019-02-04  6:58 [RFC PATCH v5 00/11] Add VM kernel tracing over vsockets and FIFOs Slavomir Kaslev
                   ` (6 preceding siblings ...)
  2019-02-04  6:58 ` [RFC PATCH v5 07/11] trace-cmd: Add `trace-cmd setup-guest` command Slavomir Kaslev
@ 2019-02-04  6:58 ` Slavomir Kaslev
  2019-02-04  6:58 ` [RFC PATCH v5 09/11] trace-cmd: Make setup-guest auto attach FIFOs to the guest VM config Slavomir Kaslev
                   ` (3 subsequent siblings)
  11 siblings, 0 replies; 13+ messages in thread
From: Slavomir Kaslev @ 2019-02-04  6:58 UTC (permalink / raw)
  To: linux-trace-devel; +Cc: rostedt, slavomir.kaslev, tstoyanov, ykaradzhov

When no number of guest CPUs is provided with the -c flag to `trace-cmd
setup-guest`, try to autodetect it using virsh for libvirt managed guests.

Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com>
---
 tracecmd/trace-setup-guest.c | 21 +++++++++++++++++++++
 tracecmd/trace-usage.c       |  2 +-
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/tracecmd/trace-setup-guest.c b/tracecmd/trace-setup-guest.c
index 1a2c8d4..bcd8f40 100644
--- a/tracecmd/trace-setup-guest.c
+++ b/tracecmd/trace-setup-guest.c
@@ -100,6 +100,24 @@ static int make_guest_fifos(const char *guest, int nr_cpus, mode_t mode)
 	return ret;
 }
 
+static int get_guest_cpu_count(const char *guest)
+{
+	const char *cmd_fmt = "virsh vcpucount --maximum '%s' 2>/dev/null";
+	int nr_cpus = -1;
+	char cmd[1024];
+	FILE *f;
+
+	snprintf(cmd, sizeof(cmd), cmd_fmt, guest);
+	f = popen(cmd, "r");
+	if (!f)
+		return -1;
+
+	fscanf(f, "%d", &nr_cpus);
+	pclose(f);
+
+	return nr_cpus;
+}
+
 static void do_setup_guest(const char *guest, int nr_cpus, mode_t mode, gid_t gid)
 {
 	gid_t save_egid;
@@ -174,6 +192,9 @@ void trace_setup_guest(int argc, char **argv)
 
 	guest = argv[optind+1];
 
+	if (nr_cpus <= 0)
+		nr_cpus = get_guest_cpu_count(guest);
+
 	if (nr_cpus <= 0)
 		pdie("invalid number of cpus for guest %s", guest);
 
diff --git a/tracecmd/trace-usage.c b/tracecmd/trace-usage.c
index 7a8002f..9a13d93 100644
--- a/tracecmd/trace-usage.c
+++ b/tracecmd/trace-usage.c
@@ -249,7 +249,7 @@ static struct usage_help usage_help[] = {
 	{
 		"setup-guest",
 		"create FIFOs for tracing guest VMs",
-		" %s setup-guest -c cpus[-p perm][-g group] guest\n"
+		" %s setup-guest [-c cpus][-p perm][-g group] guest\n"
 		"          -c number of guest virtual CPUs\n"
 		"          -p FIFOs permissions (default: 0660)\n"
 		"          -g FIFOs group owner\n"
-- 
2.19.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [RFC PATCH v5 09/11] trace-cmd: Make setup-guest auto attach FIFOs to the guest VM config
  2019-02-04  6:58 [RFC PATCH v5 00/11] Add VM kernel tracing over vsockets and FIFOs Slavomir Kaslev
                   ` (7 preceding siblings ...)
  2019-02-04  6:58 ` [RFC PATCH v5 08/11] trace-cmd: Try to autodetect number of guest CPUs in setup-guest if not specified Slavomir Kaslev
@ 2019-02-04  6:58 ` Slavomir Kaslev
  2019-02-04  6:58 ` [RFC PATCH v5 10/11] trace-cmd: Set both input and output to non-blocking when recording is stopped Slavomir Kaslev
                   ` (2 subsequent siblings)
  11 siblings, 0 replies; 13+ messages in thread
From: Slavomir Kaslev @ 2019-02-04  6:58 UTC (permalink / raw)
  To: linux-trace-devel; +Cc: rostedt, slavomir.kaslev, tstoyanov, ykaradzhov

This patch tries to attach the newly created FIFOs for guest tracing as virtio
serial devices to libvirt managed guests.

Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com>
---
 tracecmd/trace-setup-guest.c | 41 ++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/tracecmd/trace-setup-guest.c b/tracecmd/trace-setup-guest.c
index bcd8f40..3176b7e 100644
--- a/tracecmd/trace-setup-guest.c
+++ b/tracecmd/trace-setup-guest.c
@@ -118,6 +118,43 @@ static int get_guest_cpu_count(const char *guest)
 	return nr_cpus;
 }
 
+static int attach_guest_fifos(const char *guest, int nr_cpus)
+{
+	const char *cmd_fmt =
+		"virsh attach-device --config '%s' '%s' >/dev/null 2>/dev/null";
+	const char *xml_fmt =
+		"<channel type='pipe'>\n"
+		"  <source path='%s'/>\n"
+		"  <target type='virtio' name='%s%d'/>\n"
+		"</channel>";
+	char tmp_path[PATH_MAX], path[PATH_MAX];
+	char cmd[PATH_MAX], xml[PATH_MAX];
+	int i, fd, ret = 0;
+
+	strcpy(tmp_path, "/tmp/pipexmlXXXXXX");
+	fd = mkstemp(tmp_path);
+	if (fd < 0)
+		return fd;
+
+	for (i = 0; i < nr_cpus; i++) {
+		snprintf(path, sizeof(path), GUEST_FIFO_FMT, guest, i);
+		snprintf(xml, sizeof(xml), xml_fmt, path, GUEST_PIPE_NAME, i);
+		pwrite(fd, xml, strlen(xml), 0);
+
+		snprintf(cmd, sizeof(cmd), cmd_fmt, guest, tmp_path);
+		errno = 0;
+		if (system(cmd) != 0) {
+			ret = -1;
+			break;
+		}
+	}
+
+	close(fd);
+	unlink(tmp_path);
+
+	return ret;
+}
+
 static void do_setup_guest(const char *guest, int nr_cpus, mode_t mode, gid_t gid)
 {
 	gid_t save_egid;
@@ -136,6 +173,10 @@ static void do_setup_guest(const char *guest, int nr_cpus, mode_t mode, gid_t gi
 	if (ret < 0)
 		pdie("failed to create FIFOs for %s", guest);
 
+	ret = attach_guest_fifos(guest, nr_cpus);
+	if (ret < 0)
+		warning("failed to attach FIFOs to %s", guest);
+
 	ret = setegid(save_egid);
 	if (ret < 0)
 		pdie("failed to restore effective group ID");
-- 
2.19.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [RFC PATCH v5 10/11] trace-cmd: Set both input and output to non-blocking when recording is stopped
  2019-02-04  6:58 [RFC PATCH v5 00/11] Add VM kernel tracing over vsockets and FIFOs Slavomir Kaslev
                   ` (8 preceding siblings ...)
  2019-02-04  6:58 ` [RFC PATCH v5 09/11] trace-cmd: Make setup-guest auto attach FIFOs to the guest VM config Slavomir Kaslev
@ 2019-02-04  6:58 ` Slavomir Kaslev
  2019-02-04  6:58 ` [RFC PATCH v5 11/11] trace-cmd: Add VM tracing over FIFOs transport Slavomir Kaslev
  2019-02-08 21:03 ` [RFC PATCH v5 00/11] Add VM kernel tracing over vsockets and FIFOs Steven Rostedt
  11 siblings, 0 replies; 13+ messages in thread
From: Slavomir Kaslev @ 2019-02-04  6:58 UTC (permalink / raw)
  To: linux-trace-devel; +Cc: rostedt, slavomir.kaslev, tstoyanov, ykaradzhov

When tracing VMs over FIFOs both the agent and the host recording process might
get blocked doing IO over a FIFO when the other side is gone. In this case we
won't get EPIPE error (as in the vsockets case) since the FIFOs will always be
opened by the hypervisor.

Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com>
---
 lib/trace-cmd/trace-recorder.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/lib/trace-cmd/trace-recorder.c b/lib/trace-cmd/trace-recorder.c
index b750935..1c12c9e 100644
--- a/lib/trace-cmd/trace-recorder.c
+++ b/lib/trace-cmd/trace-recorder.c
@@ -40,6 +40,7 @@ struct tracecmd_recorder {
 	int		pages;
 	int		count;
 	unsigned	fd_flags;
+	unsigned	trace_fd_flags;
 	unsigned	flags;
 };
 
@@ -121,6 +122,8 @@ tracecmd_create_buffer_recorder_fd2(int fd, int fd2, int cpu, unsigned flags,
 	if (!(recorder->flags & TRACECMD_RECORD_BLOCK))
 		recorder->fd_flags |= 2; /* and NON_BLOCK */
 
+	recorder->trace_fd_flags = 1; /* SPLICE_F_MOVE */
+
 	/* Init to know what to free and release */
 	recorder->trace_fd = -1;
 	recorder->brass[0] = -1;
@@ -366,7 +369,7 @@ static long splice_data(struct tracecmd_recorder *recorder)
 	long ret;
 
 	read = splice(recorder->trace_fd, NULL, recorder->brass[1], NULL,
-		      recorder->pipe_size, 1 /* SPLICE_F_MOVE */);
+		      recorder->pipe_size, recorder->trace_fd_flags);
 	if (read < 0) {
 		if (errno != EAGAIN && errno != EINTR) {
 			warning("recorder error in splice input");
@@ -434,9 +437,12 @@ static void set_nonblock(struct tracecmd_recorder *recorder)
 	/* Do not block on reads for flushing */
 	flags = fcntl(recorder->trace_fd, F_GETFL);
 	fcntl(recorder->trace_fd, F_SETFL, flags | O_NONBLOCK);
+	recorder->trace_fd_flags |= 2; /* SPLICE_F_NONBLOCK */
 
 	/* Do not block on streams for write */
-	recorder->fd_flags |= 2; /* NON_BLOCK */
+	flags = fcntl(recorder->fd, F_GETFL);
+	fcntl(recorder->fd, F_SETFL, flags | O_NONBLOCK);
+	recorder->fd_flags |= 2; /* SPLICE_F_NONBLOCK */
 }
 
 long tracecmd_flush_recording(struct tracecmd_recorder *recorder)
-- 
2.19.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [RFC PATCH v5 11/11] trace-cmd: Add VM tracing over FIFOs transport
  2019-02-04  6:58 [RFC PATCH v5 00/11] Add VM kernel tracing over vsockets and FIFOs Slavomir Kaslev
                   ` (9 preceding siblings ...)
  2019-02-04  6:58 ` [RFC PATCH v5 10/11] trace-cmd: Set both input and output to non-blocking when recording is stopped Slavomir Kaslev
@ 2019-02-04  6:58 ` Slavomir Kaslev
  2019-02-08 21:03 ` [RFC PATCH v5 00/11] Add VM kernel tracing over vsockets and FIFOs Steven Rostedt
  11 siblings, 0 replies; 13+ messages in thread
From: Slavomir Kaslev @ 2019-02-04  6:58 UTC (permalink / raw)
  To: linux-trace-devel; +Cc: rostedt, slavomir.kaslev, tstoyanov, ykaradzhov

FIFOs offer ~3x the throughput of vsockets. This patch adds support for using
FIFOs to stream tracing data back to the host when tracing VMs.

Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com>
---
 include/trace-cmd/trace-cmd.h  |  8 ++--
 tracecmd/include/trace-local.h |  4 +-
 tracecmd/trace-agent.c         | 40 ++++++++++++++--
 tracecmd/trace-msg.c           | 26 +++++++----
 tracecmd/trace-record.c        | 84 ++++++++++++++++++++++++++++------
 5 files changed, 131 insertions(+), 31 deletions(-)

diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h
index 7664074..84dc95a 100644
--- a/include/trace-cmd/trace-cmd.h
+++ b/include/trace-cmd/trace-cmd.h
@@ -338,16 +338,16 @@ bool tracecmd_msg_done(struct tracecmd_msg_handle *msg_handle);
 void tracecmd_msg_set_done(struct tracecmd_msg_handle *msg_handle);
 
 int tracecmd_msg_send_trace_req(struct tracecmd_msg_handle *msg_handle,
-				int argc, char **argv);
+				int argc, char **argv, bool use_fifos);
 int tracecmd_msg_recv_trace_req(struct tracecmd_msg_handle *msg_handle,
-				int *argc, char ***argv);
+				int *argc, char ***argv, bool *use_fifos);
 
 int tracecmd_msg_send_trace_resp(struct tracecmd_msg_handle *msg_handle,
 				 int nr_cpus, int page_size,
-				 unsigned int *ports);
+				 unsigned int *ports, bool use_fifos);
 int tracecmd_msg_recv_trace_resp(struct tracecmd_msg_handle *msg_handle,
 				 int *nr_cpus, int *page_size,
-				 unsigned int **ports);
+				 unsigned int **ports, bool *use_fifos);
 
 int tracecmd_msg_wait_close(struct tracecmd_msg_handle *msg_handle);
 
diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h
index b23130e..8bf7c8e 100644
--- a/tracecmd/include/trace-local.h
+++ b/tracecmd/include/trace-local.h
@@ -17,6 +17,7 @@
 #define GUEST_PIPE_NAME		"trace-pipe-cpu"
 #define GUEST_DIR_FMT		"/var/lib/trace-cmd/virt/%s"
 #define GUEST_FIFO_FMT		GUEST_DIR_FMT "/" GUEST_PIPE_NAME "%d"
+#define VIRTIO_FIFO_FMT		"/dev/virtio-ports/" GUEST_PIPE_NAME "%d"
 
 extern int debug;
 extern int quiet;
@@ -100,7 +101,7 @@ void trace_usage(int argc, char **argv);
 
 int trace_record_agent(struct tracecmd_msg_handle *msg_handle,
 		       int cpus, int *fds,
-		       int argc, char **argv);
+		       int argc, char **argv, bool use_fifos);
 
 struct hook_list;
 
@@ -212,6 +213,7 @@ struct buffer_instance {
 	int			cid;
 	int			port;
 	int			*fds;
+	bool			use_fifos;
 };
 
 extern struct buffer_instance top_instance;
diff --git a/tracecmd/trace-agent.c b/tracecmd/trace-agent.c
index b4b3bbb..34e6c0c 100644
--- a/tracecmd/trace-agent.c
+++ b/tracecmd/trace-agent.c
@@ -83,12 +83,39 @@ static void make_vsocks(int nr, int *fds, unsigned int *ports)
 	}
 }
 
+static int open_agent_fifos(int nr_cpus, int *fds)
+{
+	char path[PATH_MAX];
+	int i, fd, ret = 0;
+
+	for (i = 0; i < nr_cpus; i++) {
+		snprintf(path, sizeof(path), VIRTIO_FIFO_FMT, i);
+		fd = open(path, O_WRONLY);
+		if (fd < 0) {
+			ret = -1;
+			break;
+		}
+
+		fds[i] = fd;
+	}
+
+	if (!ret)
+		return ret;
+
+	/* We failed to open all FIFOs so clean up and return error */
+	while (--i >= 0)
+		close(fds[i]);
+
+	return ret;
+}
+
 static void agent_handle(int sd, int nr_cpus, int page_size)
 {
 	struct tracecmd_msg_handle *msg_handle;
 	unsigned int *ports;
 	char **argv = NULL;
 	int argc = 0;
+	bool use_fifos;
 	int *fds;
 	int ret;
 
@@ -101,17 +128,22 @@ static void agent_handle(int sd, int nr_cpus, int page_size)
 	if (!msg_handle)
 		die("Failed to allocate message handle");
 
-	ret = tracecmd_msg_recv_trace_req(msg_handle, &argc, &argv);
+	ret = tracecmd_msg_recv_trace_req(msg_handle, &argc, &argv, &use_fifos);
 	if (ret < 0)
 		die("Failed to receive trace request");
 
-	make_vsocks(nr_cpus, fds, ports);
+	if (use_fifos && open_agent_fifos(nr_cpus, fds))
+		use_fifos = false;
+
+	if (!use_fifos)
+		make_vsocks(nr_cpus, fds, ports);
 
-	ret = tracecmd_msg_send_trace_resp(msg_handle, nr_cpus, page_size, ports);
+	ret = tracecmd_msg_send_trace_resp(msg_handle, nr_cpus, page_size,
+					   ports, use_fifos);
 	if (ret < 0)
 		die("Failed to send trace response");
 
-	trace_record_agent(msg_handle, nr_cpus, fds, argc, argv);
+	trace_record_agent(msg_handle, nr_cpus, fds, argc, argv, use_fifos);
 
 	free(argv[0]);
 	free(argv);
diff --git a/tracecmd/trace-msg.c b/tracecmd/trace-msg.c
index 7ffb8a7..c28d294 100644
--- a/tracecmd/trace-msg.c
+++ b/tracecmd/trace-msg.c
@@ -175,6 +175,10 @@ static int msg_write(int fd, struct tracecmd_msg *msg)
 	return __do_write_check(fd, msg->buf, data_size);
 }
 
+enum msg_trace_flags {
+	MSG_TRACE_USE_FIFOS = 1 << 0,
+};
+
 enum msg_opt_command {
 	MSGOPT_USETCP = 1,
 };
@@ -732,7 +736,7 @@ error:
 	return ret;
 }
 
-static int make_trace_req(struct tracecmd_msg *msg, int argc, char **argv)
+static int make_trace_req(struct tracecmd_msg *msg, int argc, char **argv, bool use_fifos)
 {
 	size_t args_size = 0;
 	char *p;
@@ -742,6 +746,7 @@ static int make_trace_req(struct tracecmd_msg *msg, int argc, char **argv)
 		args_size += strlen(argv[i]) + 1;
 
 	msg->hdr.size = htonl(ntohl(msg->hdr.size) + args_size);
+	msg->trace_req.flags = use_fifos ? htonl(MSG_TRACE_USE_FIFOS) : htonl(0);
 	msg->trace_req.argc = htonl(argc);
 	msg->buf = calloc(args_size, 1);
 	if (!msg->buf)
@@ -755,13 +760,13 @@ static int make_trace_req(struct tracecmd_msg *msg, int argc, char **argv)
 }
 
 int tracecmd_msg_send_trace_req(struct tracecmd_msg_handle *msg_handle,
-				int argc, char **argv)
+				int argc, char **argv, bool use_fifos)
 {
 	struct tracecmd_msg msg;
 	int ret;
 
 	tracecmd_msg_init(MSG_TRACE_REQ, &msg);
-	ret = make_trace_req(&msg, argc, argv);
+	ret = make_trace_req(&msg, argc, argv, use_fifos);
 	if (ret < 0)
 		return ret;
 
@@ -774,7 +779,7 @@ int tracecmd_msg_send_trace_req(struct tracecmd_msg_handle *msg_handle,
   *     free(argv);
   */
 int tracecmd_msg_recv_trace_req(struct tracecmd_msg_handle *msg_handle,
-				int *argc, char ***argv)
+				int *argc, char ***argv, bool *use_fifos)
 {
 	struct tracecmd_msg msg;
 	char *p, *buf_end, **args;
@@ -819,6 +824,7 @@ int tracecmd_msg_recv_trace_req(struct tracecmd_msg_handle *msg_handle,
 	msg.buf = NULL;
 	*argc = nr_args;
 	*argv = args;
+	*use_fifos = ntohl(msg.trace_req.flags) & MSG_TRACE_USE_FIFOS;
 	ret = 0;
 
 out:
@@ -826,13 +832,14 @@ out:
 	return ret;
 }
 
-static int make_trace_resp(struct tracecmd_msg *msg,
-			   int page_size, int nr_cpus, unsigned int *ports)
+static int make_trace_resp(struct tracecmd_msg *msg, int page_size, int nr_cpus,
+			   unsigned int *ports, bool use_fifos)
 {
 	int ports_size = nr_cpus * sizeof(*msg->port_array);
 	int i;
 
 	msg->hdr.size = htonl(ntohl(msg->hdr.size) + ports_size);
+	msg->trace_resp.flags = use_fifos ? htonl(MSG_TRACE_USE_FIFOS) : htonl(0);
 	msg->trace_resp.cpus = htonl(nr_cpus);
 	msg->trace_resp.page_size = htonl(page_size);
 
@@ -848,13 +855,13 @@ static int make_trace_resp(struct tracecmd_msg *msg,
 
 int tracecmd_msg_send_trace_resp(struct tracecmd_msg_handle *msg_handle,
 				 int nr_cpus, int page_size,
-				 unsigned int *ports)
+				 unsigned int *ports, bool use_fifos)
 {
 	struct tracecmd_msg msg;
 	int ret;
 
 	tracecmd_msg_init(MSG_TRACE_RESP, &msg);
-	ret = make_trace_resp(&msg, page_size, nr_cpus, ports);
+	ret = make_trace_resp(&msg, page_size, nr_cpus, ports, use_fifos);
 	if (ret < 0)
 		return ret;
 
@@ -863,7 +870,7 @@ int tracecmd_msg_send_trace_resp(struct tracecmd_msg_handle *msg_handle,
 
 int tracecmd_msg_recv_trace_resp(struct tracecmd_msg_handle *msg_handle,
 				 int *nr_cpus, int *page_size,
-				 unsigned int **ports)
+				 unsigned int **ports, bool *use_fifos)
 {
 	struct tracecmd_msg msg;
 	size_t buf_len;
@@ -885,6 +892,7 @@ int tracecmd_msg_recv_trace_resp(struct tracecmd_msg_handle *msg_handle,
 		goto out;
 	}
 
+	*use_fifos = ntohl(msg.trace_resp.flags) & MSG_TRACE_USE_FIFOS;
 	*nr_cpus = ntohl(msg.trace_resp.cpus);
 	*page_size = ntohl(msg.trace_resp.page_size);
 	*ports = calloc(*nr_cpus, sizeof(**ports));
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index 71176d9..43d782e 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -76,6 +76,8 @@ static int buffers;
 /* Clear all function filters */
 static int clear_function_filters;
 
+static bool no_fifos;
+
 static char *host;
 
 /* Max size to let a per cpu file get */
@@ -2914,17 +2916,20 @@ create_recorder_instance(struct buffer_instance *instance, const char *file, int
 	char *path;
 
 	if (instance->flags & BUFFER_FL_GUEST) {
-		int sd;
+		int fd;
 		unsigned int flags;
 
-		sd = open_vsock(instance->cid, instance->client_ports[cpu]);
-		if (sd < 0)
+		if (instance->use_fifos)
+			fd = instance->fds[cpu];
+		else
+			fd = open_vsock(instance->cid, instance->client_ports[cpu]);
+		if (fd < 0)
 			die("Failed to connect to agent");
 
 		flags = recorder_flags;
-		if (!can_splice_read_vsock())
+		if (!instance->use_fifos && !can_splice_read_vsock())
 			flags |= TRACECMD_RECORD_NOSPLICE;
-		return tracecmd_create_recorder_virt(file, cpu, flags, sd);
+		return tracecmd_create_recorder_virt(file, cpu, flags, fd);
 	}
 
 	if (brass)
@@ -2976,10 +2981,14 @@ static int create_recorder(struct buffer_instance *instance, int cpu,
 		char *path = NULL;
 		int fd;
 
-		if (instance->flags & BUFFER_FL_AGENT)
-			fd = do_accept(instance->fds[cpu]);
-		else
+		if (instance->flags & BUFFER_FL_AGENT) {
+			if (instance->use_fifos)
+				fd = instance->fds[cpu];
+			else
+				fd = do_accept(instance->fds[cpu]);
+		} else {
 			fd = connect_port(host, instance->client_ports[cpu]);
+		}
 		if (fd < 0)
 			die("Failed connecting to client");
 		if (instance->name && !(instance->flags & BUFFER_FL_AGENT))
@@ -3260,11 +3269,36 @@ static void finish_network(struct tracecmd_msg_handle *msg_handle)
 	free(host);
 }
 
+static int open_guest_fifos(const char *guest, int **fds)
+{
+	char path[PATH_MAX];
+	int i, fd;
+
+	for (i = 0; ; i++) {
+		snprintf(path, sizeof(path), GUEST_FIFO_FMT ".out", guest, i);
+		fd = open(path, O_RDONLY);
+		if (fd < 0)
+			break;
+
+		*fds = realloc(*fds, i + 1);
+		(*fds)[i] = fd;
+	}
+
+	return i;
+}
+
 static void connect_to_agent(struct buffer_instance *instance)
 {
 	struct tracecmd_msg_handle *msg_handle;
-	int sd, ret, nr_cpus, page_size;
+	int sd, ret, nr_fifos, nr_cpus, page_size;
 	unsigned int *ports;
+	int i, *fds = NULL;
+	bool use_fifos = false;
+
+	if (!no_fifos) {
+		nr_fifos = open_guest_fifos(instance->name, &fds);
+		use_fifos = nr_fifos > 0;
+	}
 
 	sd = open_vsock(instance->cid, instance->port);
 	if (sd < 0)
@@ -3275,15 +3309,32 @@ static void connect_to_agent(struct buffer_instance *instance)
 	if (!msg_handle)
 		die("Failed to allocate message handle");
 
-	ret = tracecmd_msg_send_trace_req(msg_handle, instance->argc, instance->argv);
+	ret = tracecmd_msg_send_trace_req(msg_handle, instance->argc,
+					  instance->argv, use_fifos);
 	if (ret < 0)
 		die("Failed to send trace request");
 
-	ret = tracecmd_msg_recv_trace_resp(msg_handle, &nr_cpus, &page_size, &ports);
+	ret = tracecmd_msg_recv_trace_resp(msg_handle, &nr_cpus, &page_size,
+					   &ports, &use_fifos);
 	if (ret < 0)
 		die("Failed to receive trace response");
 
-	instance->client_ports = ports;
+	if (use_fifos) {
+		if (nr_cpus != nr_fifos) {
+			warning("number of FIFOs for guest %s differs "
+				"from number of cpus", instance->name);
+			nr_cpus = nr_cpus < nr_fifos ? nr_cpus : nr_fifos;
+		}
+		free(ports);
+		instance->fds = fds;
+	} else {
+		for (i = 0; i < nr_fifos; i++)
+			close(fds[i]);
+		free(fds);
+		instance->client_ports = ports;
+	}
+
+	instance->use_fifos = use_fifos;
 	instance->cpu_count = nr_cpus;
 
 	/* the msg_handle now points to the guest fd */
@@ -4782,6 +4833,7 @@ enum {
 	OPT_funcstack		= 254,
 	OPT_date		= 255,
 	OPT_module		= 256,
+	OPT_nofifos		= 257,
 };
 
 void trace_stop(int argc, char **argv)
@@ -5043,6 +5095,7 @@ static void parse_record_options(int argc,
 			{"date", no_argument, NULL, OPT_date},
 			{"func-stack", no_argument, NULL, OPT_funcstack},
 			{"nosplice", no_argument, NULL, OPT_nosplice},
+			{"nofifos", no_argument, NULL, OPT_nofifos},
 			{"profile", no_argument, NULL, OPT_profile},
 			{"stderr", no_argument, NULL, OPT_stderr},
 			{"by-comm", no_argument, NULL, OPT_bycomm},
@@ -5328,6 +5381,9 @@ static void parse_record_options(int argc,
 		case OPT_nosplice:
 			recorder_flags |= TRACECMD_RECORD_NOSPLICE;
 			break;
+		case OPT_nofifos:
+			no_fifos = true;
+			break;
 		case OPT_profile:
 			handle_init = trace_init_profile;
 			ctx->instance->flags |= BUFFER_FL_PROFILE;
@@ -5724,7 +5780,8 @@ void trace_record(int argc, char **argv)
 
 int trace_record_agent(struct tracecmd_msg_handle *msg_handle,
 		       int cpus, int *fds,
-		       int argc, char **argv)
+		       int argc, char **argv,
+		       bool use_fifos)
 {
 	struct common_record_context ctx;
 	char **argv_plus;
@@ -5750,6 +5807,7 @@ int trace_record_agent(struct tracecmd_msg_handle *msg_handle,
 		return -EINVAL;
 
 	ctx.instance->fds = fds;
+	ctx.instance->use_fifos = use_fifos;
 	ctx.instance->flags |= BUFFER_FL_AGENT;
 	ctx.instance->msg_handle = msg_handle;
 	msg_handle->version = V3_PROTOCOL;
-- 
2.19.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [RFC PATCH v5 00/11] Add VM kernel tracing over vsockets and FIFOs
  2019-02-04  6:58 [RFC PATCH v5 00/11] Add VM kernel tracing over vsockets and FIFOs Slavomir Kaslev
                   ` (10 preceding siblings ...)
  2019-02-04  6:58 ` [RFC PATCH v5 11/11] trace-cmd: Add VM tracing over FIFOs transport Slavomir Kaslev
@ 2019-02-08 21:03 ` Steven Rostedt
  11 siblings, 0 replies; 13+ messages in thread
From: Steven Rostedt @ 2019-02-08 21:03 UTC (permalink / raw)
  To: Slavomir Kaslev; +Cc: linux-trace-devel, slavomir.kaslev, tstoyanov, ykaradzhov

On Mon,  4 Feb 2019 08:58:37 +0200
Slavomir Kaslev <kaslevs@vmware.com> wrote:

> This patchset adds support for tracing guest kernels to trace-cmd.

IIRC, you mentioned I should ignore these because you had another
series coming? Let me know if that's not what you said.

Also, I looked at the splice code wrt. the buffer percentage. The
splice code will return if either the file descriptor has O_NONBLOCK or
the splice command has SPLICE_F_NONBLOCK set.

Or do you think that we need to do something in case the flag changes?
To make everything non-block, we need to send a single to the code,
which should cause the code to start again.

Once the trace_fd is set to O_NONBLOCK the splice fd should return
immediately when there's nothing it can read left.

-- Steve


> 
> Changes in v5:
>  - add FIFOs transport for tracing data
>  - fixed a bug in tracecmd_msg_wait_close
> 

^ permalink raw reply	[flat|nested] 13+ messages in thread

end of thread, back to index

Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-02-04  6:58 [RFC PATCH v5 00/11] Add VM kernel tracing over vsockets and FIFOs Slavomir Kaslev
2019-02-04  6:58 ` [RFC PATCH v5 01/11] trace-cmd: Detect if vsockets are available Slavomir Kaslev
2019-02-04  6:58 ` [RFC PATCH v5 02/11] trace-cmd: Add tracecmd_create_recorder_virt function Slavomir Kaslev
2019-02-04  6:58 ` [RFC PATCH v5 03/11] trace-cmd: Add TRACE_REQ and TRACE_RESP messages Slavomir Kaslev
2019-02-04  6:58 ` [RFC PATCH v5 04/11] trace-cmd: Add buffer instance flags for tracing in guest and agent context Slavomir Kaslev
2019-02-04  6:58 ` [RFC PATCH v5 05/11] trace-cmd: Add VM kernel tracing over vsockets transport Slavomir Kaslev
2019-02-04  6:58 ` [RFC PATCH v5 06/11] trace-cmd: Use splice(2) for vsockets if available Slavomir Kaslev
2019-02-04  6:58 ` [RFC PATCH v5 07/11] trace-cmd: Add `trace-cmd setup-guest` command Slavomir Kaslev
2019-02-04  6:58 ` [RFC PATCH v5 08/11] trace-cmd: Try to autodetect number of guest CPUs in setup-guest if not specified Slavomir Kaslev
2019-02-04  6:58 ` [RFC PATCH v5 09/11] trace-cmd: Make setup-guest auto attach FIFOs to the guest VM config Slavomir Kaslev
2019-02-04  6:58 ` [RFC PATCH v5 10/11] trace-cmd: Set both input and output to non-blocking when recording is stopped Slavomir Kaslev
2019-02-04  6:58 ` [RFC PATCH v5 11/11] trace-cmd: Add VM tracing over FIFOs transport Slavomir Kaslev
2019-02-08 21:03 ` [RFC PATCH v5 00/11] Add VM kernel tracing over vsockets and FIFOs Steven Rostedt

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