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authorLinus Torvalds <torvalds@linux-foundation.org>2012-10-07 21:04:56 +0900
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-07 21:04:56 +0900
commitdc92b1f9ab1e1665dbbc56911782358e7f9a49f9 (patch)
tree965ccb4a0f2c24a8b24adce415f6506246d07a90 /tools
parent5e090ed7af10729a396a25df43d69a236e789736 (diff)
parentca16f580a5db7e60bfafe59a50bb133bd3347491 (diff)
downloadlinux-linaro-stable-dc92b1f9ab1e1665dbbc56911782358e7f9a49f9.tar.gz
Merge branch 'virtio-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull virtio changes from Rusty Russell: "New workflow: same git trees pulled by linux-next get sent straight to Linus. Git is awkward at shuffling patches compared with quilt or mq, but that doesn't happen often once things get into my -next branch." * 'virtio-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (24 commits) lguest: fix occasional crash in example launcher. virtio-blk: Disable callback in virtblk_done() virtio_mmio: Don't attempt to create empty virtqueues virtio_mmio: fix off by one error allocating queue drivers/virtio/virtio_pci.c: fix error return code virtio: don't crash when device is buggy virtio: remove CONFIG_VIRTIO_RING virtio: add help to CONFIG_VIRTIO option. virtio: support reserved vqs virtio: introduce an API to set affinity for a virtqueue virtio-ring: move queue_index to vring_virtqueue virtio_balloon: not EXPERIMENTAL any more. virtio-balloon: dependency fix virtio-blk: fix NULL checking in virtblk_alloc_req() virtio-blk: Add REQ_FLUSH and REQ_FUA support to bio path virtio-blk: Add bio-based IO path for virtio-blk virtio: console: fix error handling in init() function tools: Fix pthread flag for Makefile of trace-agent used by virtio-trace tools: Add guest trace agent as a user tool virtio/console: Allocate scatterlist according to the current pipe size ...
Diffstat (limited to 'tools')
-rw-r--r--tools/lguest/lguest.c1
-rw-r--r--tools/virtio/virtio-trace/Makefile13
-rw-r--r--tools/virtio/virtio-trace/README118
-rw-r--r--tools/virtio/virtio-trace/trace-agent-ctl.c137
-rw-r--r--tools/virtio/virtio-trace/trace-agent-rw.c192
-rw-r--r--tools/virtio/virtio-trace/trace-agent.c270
-rw-r--r--tools/virtio/virtio-trace/trace-agent.h75
7 files changed, 806 insertions, 0 deletions
diff --git a/tools/lguest/lguest.c b/tools/lguest/lguest.c
index f759f4f097c7..fd2f9221b241 100644
--- a/tools/lguest/lguest.c
+++ b/tools/lguest/lguest.c
@@ -1299,6 +1299,7 @@ static struct device *new_device(const char *name, u16 type)
dev->feature_len = 0;
dev->num_vq = 0;
dev->running = false;
+ dev->next = NULL;
/*
* Append to device list. Prepending to a single-linked list is
diff --git a/tools/virtio/virtio-trace/Makefile b/tools/virtio/virtio-trace/Makefile
new file mode 100644
index 000000000000..0d2381633475
--- /dev/null
+++ b/tools/virtio/virtio-trace/Makefile
@@ -0,0 +1,13 @@
+CC = gcc
+CFLAGS = -O2 -Wall -pthread
+
+all: trace-agent
+
+.c.o:
+ $(CC) $(CFLAGS) -c $^ -o $@
+
+trace-agent: trace-agent.o trace-agent-ctl.o trace-agent-rw.o
+ $(CC) $(CFLAGS) -o $@ $^
+
+clean:
+ rm -f *.o trace-agent
diff --git a/tools/virtio/virtio-trace/README b/tools/virtio/virtio-trace/README
new file mode 100644
index 000000000000..b64845b823ab
--- /dev/null
+++ b/tools/virtio/virtio-trace/README
@@ -0,0 +1,118 @@
+Trace Agent for virtio-trace
+============================
+
+Trace agent is a user tool for sending trace data of a guest to a Host in low
+overhead. Trace agent has the following functions:
+ - splice a page of ring-buffer to read_pipe without memory copying
+ - splice the page from write_pipe to virtio-console without memory copying
+ - write trace data to stdout by using -o option
+ - controlled by start/stop orders from a Host
+
+The trace agent operates as follows:
+ 1) Initialize all structures.
+ 2) Create a read/write thread per CPU. Each thread is bound to a CPU.
+ The read/write threads hold it.
+ 3) A controller thread does poll() for a start order of a host.
+ 4) After the controller of the trace agent receives a start order from a host,
+ the controller wake read/write threads.
+ 5) The read/write threads start to read trace data from ring-buffers and
+ write the data to virtio-serial.
+ 6) If the controller receives a stop order from a host, the read/write threads
+ stop to read trace data.
+
+
+Files
+=====
+
+README: this file
+Makefile: Makefile of trace agent for virtio-trace
+trace-agent.c: includes main function, sets up for operating trace agent
+trace-agent.h: includes all structures and some macros
+trace-agent-ctl.c: includes controller function for read/write threads
+trace-agent-rw.c: includes read/write threads function
+
+
+Setup
+=====
+
+To use this trace agent for virtio-trace, we need to prepare some virtio-serial
+I/Fs.
+
+1) Make FIFO in a host
+ virtio-trace uses virtio-serial pipe as trace data paths as to the number
+of CPUs and a control path, so FIFO (named pipe) should be created as follows:
+ # mkdir /tmp/virtio-trace/
+ # mkfifo /tmp/virtio-trace/trace-path-cpu{0,1,2,...,X}.{in,out}
+ # mkfifo /tmp/virtio-trace/agent-ctl-path.{in,out}
+
+For example, if a guest use three CPUs, the names are
+ trace-path-cpu{0,1,2}.{in.out}
+and
+ agent-ctl-path.{in,out}.
+
+2) Set up of virtio-serial pipe in a host
+ Add qemu option to use virtio-serial pipe.
+
+ ##virtio-serial device##
+ -device virtio-serial-pci,id=virtio-serial0\
+ ##control path##
+ -chardev pipe,id=charchannel0,path=/tmp/virtio-trace/agent-ctl-path\
+ -device virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,\
+ id=channel0,name=agent-ctl-path\
+ ##data path##
+ -chardev pipe,id=charchannel1,path=/tmp/virtio-trace/trace-path-cpu0\
+ -device virtserialport,bus=virtio-serial0.0,nr=2,chardev=charchannel0,\
+ id=channel1,name=trace-path-cpu0\
+ ...
+
+If you manage guests with libvirt, add the following tags to domain XML files.
+Then, libvirt passes the same command option to qemu.
+
+ <channel type='pipe'>
+ <source path='/tmp/virtio-trace/agent-ctl-path'/>
+ <target type='virtio' name='agent-ctl-path'/>
+ <address type='virtio-serial' controller='0' bus='0' port='0'/>
+ </channel>
+ <channel type='pipe'>
+ <source path='/tmp/virtio-trace/trace-path-cpu0'/>
+ <target type='virtio' name='trace-path-cpu0'/>
+ <address type='virtio-serial' controller='0' bus='0' port='1'/>
+ </channel>
+ ...
+Here, chardev names are restricted to trace-path-cpuX and agent-ctl-path. For
+example, if a guest use three CPUs, chardev names should be trace-path-cpu0,
+trace-path-cpu1, trace-path-cpu2, and agent-ctl-path.
+
+3) Boot the guest
+ You can find some chardev in /dev/virtio-ports/ in the guest.
+
+
+Run
+===
+
+0) Build trace agent in a guest
+ $ make
+
+1) Enable ftrace in the guest
+ <Example>
+ # echo 1 > /sys/kernel/debug/tracing/events/sched/enable
+
+2) Run trace agent in the guest
+ This agent must be operated as root.
+ # ./trace-agent
+read/write threads in the agent wait for start order from host. If you add -o
+option, trace data are output via stdout in the guest.
+
+3) Open FIFO in a host
+ # cat /tmp/virtio-trace/trace-path-cpu0.out
+If a host does not open these, trace data get stuck in buffers of virtio. Then,
+the guest will stop by specification of chardev in QEMU. This blocking mode may
+be solved in the future.
+
+4) Start to read trace data by ordering from a host
+ A host injects read start order to the guest via virtio-serial.
+ # echo 1 > /tmp/virtio-trace/agent-ctl-path.in
+
+5) Stop to read trace data by ordering from a host
+ A host injects read stop order to the guest via virtio-serial.
+ # echo 0 > /tmp/virtio-trace/agent-ctl-path.in
diff --git a/tools/virtio/virtio-trace/trace-agent-ctl.c b/tools/virtio/virtio-trace/trace-agent-ctl.c
new file mode 100644
index 000000000000..a2d0403c4f94
--- /dev/null
+++ b/tools/virtio/virtio-trace/trace-agent-ctl.c
@@ -0,0 +1,137 @@
+/*
+ * Controller of read/write threads for virtio-trace
+ *
+ * Copyright (C) 2012 Hitachi, Ltd.
+ * Created by Yoshihiro Yunomae <yoshihiro.yunomae.ez@hitachi.com>
+ * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
+ *
+ * Licensed under GPL version 2 only.
+ *
+ */
+
+#define _GNU_SOURCE
+#include <fcntl.h>
+#include <poll.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include "trace-agent.h"
+
+#define HOST_MSG_SIZE 256
+#define EVENT_WAIT_MSEC 100
+
+static volatile sig_atomic_t global_signal_val;
+bool global_sig_receive; /* default false */
+bool global_run_operation; /* default false*/
+
+/* Handle SIGTERM/SIGINT/SIGQUIT to exit */
+static void signal_handler(int sig)
+{
+ global_signal_val = sig;
+}
+
+int rw_ctl_init(const char *ctl_path)
+{
+ int ctl_fd;
+
+ ctl_fd = open(ctl_path, O_RDONLY);
+ if (ctl_fd == -1) {
+ pr_err("Cannot open ctl_fd\n");
+ goto error;
+ }
+
+ return ctl_fd;
+
+error:
+ exit(EXIT_FAILURE);
+}
+
+static int wait_order(int ctl_fd)
+{
+ struct pollfd poll_fd;
+ int ret = 0;
+
+ while (!global_sig_receive) {
+ poll_fd.fd = ctl_fd;
+ poll_fd.events = POLLIN;
+
+ ret = poll(&poll_fd, 1, EVENT_WAIT_MSEC);
+
+ if (global_signal_val) {
+ global_sig_receive = true;
+ pr_info("Receive interrupt %d\n", global_signal_val);
+
+ /* Wakes rw-threads when they are sleeping */
+ if (!global_run_operation)
+ pthread_cond_broadcast(&cond_wakeup);
+
+ ret = -1;
+ break;
+ }
+
+ if (ret < 0) {
+ pr_err("Polling error\n");
+ goto error;
+ }
+
+ if (ret)
+ break;
+ };
+
+ return ret;
+
+error:
+ exit(EXIT_FAILURE);
+}
+
+/*
+ * contol read/write threads by handling global_run_operation
+ */
+void *rw_ctl_loop(int ctl_fd)
+{
+ ssize_t rlen;
+ char buf[HOST_MSG_SIZE];
+ int ret;
+
+ /* Setup signal handlers */
+ signal(SIGTERM, signal_handler);
+ signal(SIGINT, signal_handler);
+ signal(SIGQUIT, signal_handler);
+
+ while (!global_sig_receive) {
+
+ ret = wait_order(ctl_fd);
+ if (ret < 0)
+ break;
+
+ rlen = read(ctl_fd, buf, sizeof(buf));
+ if (rlen < 0) {
+ pr_err("read data error in ctl thread\n");
+ goto error;
+ }
+
+ if (rlen == 2 && buf[0] == '1') {
+ /*
+ * If host writes '1' to a control path,
+ * this controller wakes all read/write threads.
+ */
+ global_run_operation = true;
+ pthread_cond_broadcast(&cond_wakeup);
+ pr_debug("Wake up all read/write threads\n");
+ } else if (rlen == 2 && buf[0] == '0') {
+ /*
+ * If host writes '0' to a control path, read/write
+ * threads will wait for notification from Host.
+ */
+ global_run_operation = false;
+ pr_debug("Stop all read/write threads\n");
+ } else
+ pr_info("Invalid host notification: %s\n", buf);
+ }
+
+ return NULL;
+
+error:
+ exit(EXIT_FAILURE);
+}
diff --git a/tools/virtio/virtio-trace/trace-agent-rw.c b/tools/virtio/virtio-trace/trace-agent-rw.c
new file mode 100644
index 000000000000..3aace5ea4842
--- /dev/null
+++ b/tools/virtio/virtio-trace/trace-agent-rw.c
@@ -0,0 +1,192 @@
+/*
+ * Read/write thread of a guest agent for virtio-trace
+ *
+ * Copyright (C) 2012 Hitachi, Ltd.
+ * Created by Yoshihiro Yunomae <yoshihiro.yunomae.ez@hitachi.com>
+ * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
+ *
+ * Licensed under GPL version 2 only.
+ *
+ */
+
+#define _GNU_SOURCE
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include "trace-agent.h"
+
+#define READ_WAIT_USEC 100000
+
+void *rw_thread_info_new(void)
+{
+ struct rw_thread_info *rw_ti;
+
+ rw_ti = zalloc(sizeof(struct rw_thread_info));
+ if (rw_ti == NULL) {
+ pr_err("rw_thread_info zalloc error\n");
+ exit(EXIT_FAILURE);
+ }
+
+ rw_ti->cpu_num = -1;
+ rw_ti->in_fd = -1;
+ rw_ti->out_fd = -1;
+ rw_ti->read_pipe = -1;
+ rw_ti->write_pipe = -1;
+ rw_ti->pipe_size = PIPE_INIT;
+
+ return rw_ti;
+}
+
+void *rw_thread_init(int cpu, const char *in_path, const char *out_path,
+ bool stdout_flag, unsigned long pipe_size,
+ struct rw_thread_info *rw_ti)
+{
+ int data_pipe[2];
+
+ rw_ti->cpu_num = cpu;
+
+ /* set read(input) fd */
+ rw_ti->in_fd = open(in_path, O_RDONLY);
+ if (rw_ti->in_fd == -1) {
+ pr_err("Could not open in_fd (CPU:%d)\n", cpu);
+ goto error;
+ }
+
+ /* set write(output) fd */
+ if (!stdout_flag) {
+ /* virtio-serial output mode */
+ rw_ti->out_fd = open(out_path, O_WRONLY);
+ if (rw_ti->out_fd == -1) {
+ pr_err("Could not open out_fd (CPU:%d)\n", cpu);
+ goto error;
+ }
+ } else
+ /* stdout mode */
+ rw_ti->out_fd = STDOUT_FILENO;
+
+ if (pipe2(data_pipe, O_NONBLOCK) < 0) {
+ pr_err("Could not create pipe in rw-thread(%d)\n", cpu);
+ goto error;
+ }
+
+ /*
+ * Size of pipe is 64kB in default based on fs/pipe.c.
+ * To read/write trace data speedy, pipe size is changed.
+ */
+ if (fcntl(*data_pipe, F_SETPIPE_SZ, pipe_size) < 0) {
+ pr_err("Could not change pipe size in rw-thread(%d)\n", cpu);
+ goto error;
+ }
+
+ rw_ti->read_pipe = data_pipe[1];
+ rw_ti->write_pipe = data_pipe[0];
+ rw_ti->pipe_size = pipe_size;
+
+ return NULL;
+
+error:
+ exit(EXIT_FAILURE);
+}
+
+/* Bind a thread to a cpu */
+static void bind_cpu(int cpu_num)
+{
+ cpu_set_t mask;
+
+ CPU_ZERO(&mask);
+ CPU_SET(cpu_num, &mask);
+
+ /* bind my thread to cpu_num by assigning zero to the first argument */
+ if (sched_setaffinity(0, sizeof(mask), &mask) == -1)
+ pr_err("Could not set CPU#%d affinity\n", (int)cpu_num);
+}
+
+static void *rw_thread_main(void *thread_info)
+{
+ ssize_t rlen, wlen;
+ ssize_t ret;
+ struct rw_thread_info *ts = (struct rw_thread_info *)thread_info;
+
+ bind_cpu(ts->cpu_num);
+
+ while (1) {
+ /* Wait for a read order of trace data by Host OS */
+ if (!global_run_operation) {
+ pthread_mutex_lock(&mutex_notify);
+ pthread_cond_wait(&cond_wakeup, &mutex_notify);
+ pthread_mutex_unlock(&mutex_notify);
+ }
+
+ if (global_sig_receive)
+ break;
+
+ /*
+ * Each thread read trace_pipe_raw of each cpu bounding the
+ * thread, so contention of multi-threads does not occur.
+ */
+ rlen = splice(ts->in_fd, NULL, ts->read_pipe, NULL,
+ ts->pipe_size, SPLICE_F_MOVE | SPLICE_F_MORE);
+
+ if (rlen < 0) {
+ pr_err("Splice_read in rw-thread(%d)\n", ts->cpu_num);
+ goto error;
+ } else if (rlen == 0) {
+ /*
+ * If trace data do not exist or are unreadable not
+ * for exceeding the page size, splice_read returns
+ * NULL. Then, this waits for being filled the data in a
+ * ring-buffer.
+ */
+ usleep(READ_WAIT_USEC);
+ pr_debug("Read retry(cpu:%d)\n", ts->cpu_num);
+ continue;
+ }
+
+ wlen = 0;
+
+ do {
+ ret = splice(ts->write_pipe, NULL, ts->out_fd, NULL,
+ rlen - wlen,
+ SPLICE_F_MOVE | SPLICE_F_MORE);
+
+ if (ret < 0) {
+ pr_err("Splice_write in rw-thread(%d)\n",
+ ts->cpu_num);
+ goto error;
+ } else if (ret == 0)
+ /*
+ * When host reader is not in time for reading
+ * trace data, guest will be stopped. This is
+ * because char dev in QEMU is not supported
+ * non-blocking mode. Then, writer might be
+ * sleep in that case.
+ * This sleep will be removed by supporting
+ * non-blocking mode.
+ */
+ sleep(1);
+ wlen += ret;
+ } while (wlen < rlen);
+ }
+
+ return NULL;
+
+error:
+ exit(EXIT_FAILURE);
+}
+
+
+pthread_t rw_thread_run(struct rw_thread_info *rw_ti)
+{
+ int ret;
+ pthread_t rw_thread_per_cpu;
+
+ ret = pthread_create(&rw_thread_per_cpu, NULL, rw_thread_main, rw_ti);
+ if (ret != 0) {
+ pr_err("Could not create a rw thread(%d)\n", rw_ti->cpu_num);
+ exit(EXIT_FAILURE);
+ }
+
+ return rw_thread_per_cpu;
+}
diff --git a/tools/virtio/virtio-trace/trace-agent.c b/tools/virtio/virtio-trace/trace-agent.c
new file mode 100644
index 000000000000..0a0a7dd4eff7
--- /dev/null
+++ b/tools/virtio/virtio-trace/trace-agent.c
@@ -0,0 +1,270 @@
+/*
+ * Guest agent for virtio-trace
+ *
+ * Copyright (C) 2012 Hitachi, Ltd.
+ * Created by Yoshihiro Yunomae <yoshihiro.yunomae.ez@hitachi.com>
+ * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
+ *
+ * Licensed under GPL version 2 only.
+ *
+ */
+
+#define _GNU_SOURCE
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include "trace-agent.h"
+
+#define PAGE_SIZE (sysconf(_SC_PAGE_SIZE))
+#define PIPE_DEF_BUFS 16
+#define PIPE_MIN_SIZE (PAGE_SIZE*PIPE_DEF_BUFS)
+#define PIPE_MAX_SIZE (1024*1024)
+#define READ_PATH_FMT \
+ "/sys/kernel/debug/tracing/per_cpu/cpu%d/trace_pipe_raw"
+#define WRITE_PATH_FMT "/dev/virtio-ports/trace-path-cpu%d"
+#define CTL_PATH "/dev/virtio-ports/agent-ctl-path"
+
+pthread_mutex_t mutex_notify = PTHREAD_MUTEX_INITIALIZER;
+pthread_cond_t cond_wakeup = PTHREAD_COND_INITIALIZER;
+
+static int get_total_cpus(void)
+{
+ int nr_cpus = (int)sysconf(_SC_NPROCESSORS_CONF);
+
+ if (nr_cpus <= 0) {
+ pr_err("Could not read cpus\n");
+ goto error;
+ } else if (nr_cpus > MAX_CPUS) {
+ pr_err("Exceed max cpus(%d)\n", (int)MAX_CPUS);
+ goto error;
+ }
+
+ return nr_cpus;
+
+error:
+ exit(EXIT_FAILURE);
+}
+
+static void *agent_info_new(void)
+{
+ struct agent_info *s;
+ int i;
+
+ s = zalloc(sizeof(struct agent_info));
+ if (s == NULL) {
+ pr_err("agent_info zalloc error\n");
+ exit(EXIT_FAILURE);
+ }
+
+ s->pipe_size = PIPE_INIT;
+ s->use_stdout = false;
+ s->cpus = get_total_cpus();
+ s->ctl_fd = -1;
+
+ /* read/write threads init */
+ for (i = 0; i < s->cpus; i++)
+ s->rw_ti[i] = rw_thread_info_new();
+
+ return s;
+}
+
+static unsigned long parse_size(const char *arg)
+{
+ unsigned long value, round;
+ char *ptr;
+
+ value = strtoul(arg, &ptr, 10);
+ switch (*ptr) {
+ case 'K': case 'k':
+ value <<= 10;
+ break;
+ case 'M': case 'm':
+ value <<= 20;
+ break;
+ default:
+ break;
+ }
+
+ if (value > PIPE_MAX_SIZE) {
+ pr_err("Pipe size must be less than 1MB\n");
+ goto error;
+ } else if (value < PIPE_MIN_SIZE) {
+ pr_err("Pipe size must be over 64KB\n");
+ goto error;
+ }
+
+ /* Align buffer size with page unit */
+ round = value & (PAGE_SIZE - 1);
+ value = value - round;
+
+ return value;
+error:
+ return 0;
+}
+
+static void usage(char const *prg)
+{
+ pr_err("usage: %s [-h] [-o] [-s <size of pipe>]\n", prg);
+}
+
+static const char *make_path(int cpu_num, bool this_is_write_path)
+{
+ int ret;
+ char *buf;
+
+ buf = zalloc(PATH_MAX);
+ if (buf == NULL) {
+ pr_err("Could not allocate buffer\n");
+ goto error;
+ }
+
+ if (this_is_write_path)
+ /* write(output) path */
+ ret = snprintf(buf, PATH_MAX, WRITE_PATH_FMT, cpu_num);
+ else
+ /* read(input) path */
+ ret = snprintf(buf, PATH_MAX, READ_PATH_FMT, cpu_num);
+
+ if (ret <= 0) {
+ pr_err("Failed to generate %s path(CPU#%d):%d\n",
+ this_is_write_path ? "read" : "write", cpu_num, ret);
+ goto error;
+ }
+
+ return buf;
+
+error:
+ free(buf);
+ return NULL;
+}
+
+static const char *make_input_path(int cpu_num)
+{
+ return make_path(cpu_num, false);
+}
+
+static const char *make_output_path(int cpu_num)
+{
+ return make_path(cpu_num, true);
+}
+
+static void *agent_info_init(struct agent_info *s)
+{
+ int cpu;
+ const char *in_path = NULL;
+ const char *out_path = NULL;
+
+ /* init read/write threads */
+ for (cpu = 0; cpu < s->cpus; cpu++) {
+ /* set read(input) path per read/write thread */
+ in_path = make_input_path(cpu);
+ if (in_path == NULL)
+ goto error;
+
+ /* set write(output) path per read/write thread*/
+ if (!s->use_stdout) {
+ out_path = make_output_path(cpu);
+ if (out_path == NULL)
+ goto error;
+ } else
+ /* stdout mode */
+ pr_debug("stdout mode\n");
+
+ rw_thread_init(cpu, in_path, out_path, s->use_stdout,
+ s->pipe_size, s->rw_ti[cpu]);
+ }
+
+ /* init controller of read/write threads */
+ s->ctl_fd = rw_ctl_init((const char *)CTL_PATH);
+
+ return NULL;
+
+error:
+ exit(EXIT_FAILURE);
+}
+
+static void *parse_args(int argc, char *argv[], struct agent_info *s)
+{
+ int cmd;
+ unsigned long size;
+
+ while ((cmd = getopt(argc, argv, "hos:")) != -1) {
+ switch (cmd) {
+ /* stdout mode */
+ case 'o':
+ s->use_stdout = true;
+ break;
+ /* size of pipe */
+ case 's':
+ size = parse_size(optarg);
+ if (size == 0)
+ goto error;
+ s->pipe_size = size;
+ break;
+ case 'h':
+ default:
+ usage(argv[0]);
+ goto error;
+ }
+ }
+
+ agent_info_init(s);
+
+ return NULL;
+
+error:
+ exit(EXIT_FAILURE);
+}
+
+static void agent_main_loop(struct agent_info *s)
+{
+ int cpu;
+ pthread_t rw_thread_per_cpu[MAX_CPUS];
+
+ /* Start all read/write threads */
+ for (cpu = 0; cpu < s->cpus; cpu++)
+ rw_thread_per_cpu[cpu] = rw_thread_run(s->rw_ti[cpu]);
+
+ rw_ctl_loop(s->ctl_fd);
+
+ /* Finish all read/write threads */
+ for (cpu = 0; cpu < s->cpus; cpu++) {
+ int ret;
+
+ ret = pthread_join(rw_thread_per_cpu[cpu], NULL);
+ if (ret != 0) {
+ pr_err("pthread_join() error:%d (cpu %d)\n", ret, cpu);
+ exit(EXIT_FAILURE);
+ }
+ }
+}
+
+static void agent_info_free(struct agent_info *s)
+{
+ int i;
+
+ close(s->ctl_fd);
+ for (i = 0; i < s->cpus; i++) {
+ close(s->rw_ti[i]->in_fd);
+ close(s->rw_ti[i]->out_fd);
+ close(s->rw_ti[i]->read_pipe);
+ close(s->rw_ti[i]->write_pipe);
+ free(s->rw_ti[i]);
+ }
+ free(s);
+}
+
+int main(int argc, char *argv[])
+{
+ struct agent_info *s = NULL;
+
+ s = agent_info_new();
+ parse_args(argc, argv, s);
+
+ agent_main_loop(s);
+
+ agent_info_free(s);
+
+ return 0;
+}
diff --git a/tools/virtio/virtio-trace/trace-agent.h b/tools/virtio/virtio-trace/trace-agent.h
new file mode 100644
index 000000000000..8de79bfeaa73
--- /dev/null
+++ b/tools/virtio/virtio-trace/trace-agent.h
@@ -0,0 +1,75 @@
+#ifndef __TRACE_AGENT_H__
+#define __TRACE_AGENT_H__
+#include <pthread.h>
+#include <stdbool.h>
+
+#define MAX_CPUS 256
+#define PIPE_INIT (1024*1024)
+
+/*
+ * agent_info - structure managing total information of guest agent
+ * @pipe_size: size of pipe (default 1MB)
+ * @use_stdout: set to true when o option is added (default false)
+ * @cpus: total number of CPUs
+ * @ctl_fd: fd of control path, /dev/virtio-ports/agent-ctl-path
+ * @rw_ti: structure managing information of read/write threads
+ */
+struct agent_info {
+ unsigned long pipe_size;
+ bool use_stdout;
+ int cpus;
+ int ctl_fd;
+ struct rw_thread_info *rw_ti[MAX_CPUS];
+};
+
+/*
+ * rw_thread_info - structure managing a read/write thread a cpu
+ * @cpu_num: cpu number operating this read/write thread
+ * @in_fd: fd of reading trace data path in cpu_num
+ * @out_fd: fd of writing trace data path in cpu_num
+ * @read_pipe: fd of read pipe
+ * @write_pipe: fd of write pipe
+ * @pipe_size: size of pipe (default 1MB)
+ */
+struct rw_thread_info {
+ int cpu_num;
+ int in_fd;
+ int out_fd;
+ int read_pipe;
+ int write_pipe;
+ unsigned long pipe_size;
+};
+
+/* use for stopping rw threads */
+extern bool global_sig_receive;
+
+/* use for notification */
+extern bool global_run_operation;
+extern pthread_mutex_t mutex_notify;
+extern pthread_cond_t cond_wakeup;
+
+/* for controller of read/write threads */
+extern int rw_ctl_init(const char *ctl_path);
+extern void *rw_ctl_loop(int ctl_fd);
+
+/* for trace read/write thread */
+extern void *rw_thread_info_new(void);
+extern void *rw_thread_init(int cpu, const char *in_path, const char *out_path,
+ bool stdout_flag, unsigned long pipe_size,
+ struct rw_thread_info *rw_ti);
+extern pthread_t rw_thread_run(struct rw_thread_info *rw_ti);
+
+static inline void *zalloc(size_t size)
+{
+ return calloc(1, size);
+}
+
+#define pr_err(format, ...) fprintf(stderr, format, ## __VA_ARGS__)
+#define pr_info(format, ...) fprintf(stdout, format, ## __VA_ARGS__)
+#ifdef DEBUG
+#define pr_debug(format, ...) fprintf(stderr, format, ## __VA_ARGS__)
+#else
+#define pr_debug(format, ...) do {} while (0)
+#endif
+
+#endif /*__TRACE_AGENT_H__*/