[PATCH V4 4/5] trace-cmd/virt-server: Add --dom option which makes a domain directory to virt-server

From: Yoshihiro YUNOMAE
Date: Thu Jul 10 2014 - 20:59:14 EST

Add --dom option which makes a domain directory to virt-server. When a user
already knows domain name of a guest before running virt-server, trace-cmd
should automatically set up I/Fs of the guest. By adding --dom option,
trace-cmd creates a domain directory with 0710 and qemu group.

This patch adds additional options for --dom as follows:

-m <permission>
This option changes the permission of domain directory. If you don't use
this option, the default permission is 0710.

-g <group>
This option changes group of domain directory. If you don't use this option,
the default group is qemu.

-c <cpu>
This option creates trace data I/Fs(trace-path-cpu*.{in,out}) for each CPU
of 'domain'. If you don't use this option, those files are not created.

Here, an example you use this option is written as follows:

- trace-cmd creates a guest1 directory with trace data I/Fs of 2 CPUs.
# trace-cmd virt-server --dom guest1 -c 2

- trace-cmd creates guest2 and guest3 directories
# trace-cmd virt-server --dom guest2 -c 3 --dom guest3 -c 1

Changes in V4: Introduce parse_args_virt()
Add usage of virt-server in trace-usage.c

Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@xxxxxxxxxxx>
---
Documentation/trace-cmd-virt-server.1.txt | 56 ++++++++---
trace-listen.c | 151 ++++++++++++++++++++++++++---
trace-usage.c | 5 +
3 files changed, 178 insertions(+), 34 deletions(-)

diff --git a/Documentation/trace-cmd-virt-server.1.txt b/Documentation/trace-cmd-virt-server.1.txt
index 4168a04..fbd0ad6 100644
--- a/Documentation/trace-cmd-virt-server.1.txt
+++ b/Documentation/trace-cmd-virt-server.1.txt
@@ -34,40 +34,64 @@ OPTIONS
*-l* 'filename'::
This option writes the output messages to a log file instead of standard output.

+*--dom* 'domain'::
+ This option makes a directory for the 'domain'. You can use additional options
+ *-m*, *-g*, *-c* after this option for the 'domain'. If you don't use these
+ additional options, the directory is made as 0710 and qemu group and
+ trace data I/Fs(trace-path-cpu*.{in,out}) are not created.
+
+*-m* 'permission'::
+ This option changes the permission of 'domain' directory. If you don't use
+ this option, the default permission is 0710.
+
+*-g* 'group'::
+ This option changes group of 'domain' directory. If you don't use this option,
+ the default group is qemu.
+
+*-c* 'cpu'::
+ This option creates trace data I/Fs(trace-path-cpu*.{in,out}) for each CPU
+ of 'domain'. If you don't use this option, those files are not created.
+
SET UP
------
Here, an example is written as follows:

1. Run virt-server on a host
- # trace-cmd virt-server
-
-2. Make guest domain directory
- # mkdir -p /tmp/trace-cmd/virt/<DOMAIN>
- # chmod 710 /tmp/trace-cmd/virt/<DOMAIN>
- # chgrp qemu /tmp/trace-cmd/virt/<DOMAIN>
-
-3. Make FIFO on the host
- # mkfifo /tmp/trace-cmd/virt/<DOMAIN>/trace-path-cpu{0,1,...,X}.{in,out}
+ # trace-cmd virt-server --dom guest1 -c 2

-4. Set up of virtio-serial pipe of a guest on the host
+2. Set up of virtio-serial pipe of guest1 on the host
Add the following tags to domain XML files.
- # virsh edit <guest domain>
+ # virsh edit guest1
<channel type='unix'>
<source mode='connect' path='/tmp/trace-cmd/virt/agent-ctl-path'/>
<target type='virtio' name='agent-ctl-path'/>
</channel>
<channel type='pipe'>
- <source path='/tmp/trace-cmd/virt/<DOMAIN>/trace-path-cpu0'/>
+ <source path='/tmp/trace-cmd/virt/guest1/trace-path-cpu0'/>
<target type='virtio' name='trace-path-cpu0'/>
</channel>
- ... (cpu1, cpu2, ...)
+ <channel type='pipe'>
+ <source path='/tmp/trace-cmd/virt/guest1/trace-path-cpu1'/>
+ <target type='virtio' name='trace-path-cpu1'/>
+ </channel>

-5. Boot the guest
- # virsh start <DOMAIN>
+3. Boot the guest
+ # virsh start guest1

-6. Run the guest's client(see trace-cmd-record(1) with the *--virt* option)
+4. Run the guest1's client(see trace-cmd-record(1) with the *--virt* option)
# trace-cmd record -e sched* --virt

+If you want to boot another guest sends trace-data via virtio-serial,
+you will manually make the guest domain directory and trace data I/Fs.
+
+- Make guest domain directory on the host
+ # mkdir -p /tmp/trace-cmd/virt/<DOMAIN>
+ # chmod 710 /tmp/trace-cmd/virt/<DOMAIN>
+ # chgrp qemu /tmp/trace-cmd/virt/<DOMAIN>
+
+- Make FIFO on the host
+ # mkfifo /tmp/trace-cmd/virt/<DOMAIN>/trace-path-cpu{0,1,...,X}.{in,out}
+
SEE ALSO
--------
trace-cmd(1), trace-cmd-record(1), trace-cmd-report(1), trace-cmd-start(1),
diff --git a/trace-listen.c b/trace-listen.c
index 01b7ebf..e424c2a 100644
--- a/trace-listen.c
+++ b/trace-listen.c
@@ -54,11 +54,21 @@ static int backlog = 5;

static int proto_ver;

+struct domain_dir {
+ struct domain_dir *next;
+ char *name;
+ char *group;
+ mode_t perms;
+ int cpu;
+};
+
enum {
NET = 1,
VIRT = 2,
};

+struct domain_dir *dom_dir_list;
+
#define TEMP_FILE_STR_NET "%s.%s:%s.cpu%d", output_file, host, port, cpu
#define TEMP_FILE_STR_VIRT "%s.%s:%d.cpu%d", output_file, domain, virtpid, cpu
static char *get_temp_file(const char *host, const char *port,
@@ -382,7 +392,9 @@ static int open_udp(const char *node, const char *port, int *pid,
#define TRACE_CMD_DIR "/tmp/trace-cmd/"
#define VIRT_DIR TRACE_CMD_DIR "virt/"
#define VIRT_TRACE_CTL_SOCK VIRT_DIR "agent-ctl-path"
-#define TRACE_PATH_DOMAIN_CPU VIRT_DIR "%s/trace-path-cpu%d.out"
+#define VIRT_DOMAIN_DIR VIRT_DIR "%s/"
+#define TRACE_PATH_DOMAIN_CPU_O VIRT_DOMAIN_DIR "trace-path-cpu%d.out"
+#define TRACE_PATH_DOMAIN_CPU_I VIRT_DOMAIN_DIR "trace-path-cpu%d.in"

static int open_virtio_serial_pipe(int *pid, int cpu, int pagesize,
const char *domain, int virtpid)
@@ -390,7 +402,7 @@ static int open_virtio_serial_pipe(int *pid, int cpu, int pagesize,
char buf[PATH_MAX];
int fd;

- snprintf(buf, PATH_MAX, TRACE_PATH_DOMAIN_CPU, domain, cpu);
+ snprintf(buf, PATH_MAX, TRACE_PATH_DOMAIN_CPU_O, domain, cpu);
fd = open(buf, O_RDONLY | O_NONBLOCK);
if (fd < 0) {
warning("open %s", buf);
@@ -995,27 +1007,89 @@ static void do_listen_net(char *port)
kill_clients();
}

-static void make_virt_if_dir(void)
+#define for_each_domain(i) for (i = dom_dir_list; i; i = (i)->next)
+
+static void make_dir_virt(const char *path, mode_t perms, const char *gr_name)
{
struct group *group;

- if (mkdir(TRACE_CMD_DIR, 0710) < 0) {
+ if (mkdir(path, perms) < 0) {
if (errno != EEXIST)
- pdie("mkdir %s", TRACE_CMD_DIR);
+ pdie("mkdir %s", path);
}
- /* QEMU operates as qemu:qemu */
- chmod(TRACE_CMD_DIR, 0710);
- group = getgrnam("qemu");
- if (chown(TRACE_CMD_DIR, -1, group->gr_gid) < 0)
- pdie("chown %s", TRACE_CMD_DIR);
+ chmod(path, perms);

- if (mkdir(VIRT_DIR, 0710) < 0) {
- if (errno != EEXIST)
- pdie("mkdir %s", VIRT_DIR);
+ group = getgrnam(gr_name);
+ if (!group)
+ pdie("getgrnam %s", gr_name);
+ if (chown(path, -1, group->gr_gid) < 0)
+ pdie("chown %s", path);
+}
+
+static void make_traceif_in_dom_dir(const char *name, int cpu)
+{
+ char fifo_in[PATH_MAX];
+ char fifo_out[PATH_MAX];
+ int i;
+
+ for (i = 0; i < cpu; i++) {
+ snprintf(fifo_in, PATH_MAX, TRACE_PATH_DOMAIN_CPU_I, name, i);
+ snprintf(fifo_out, PATH_MAX, TRACE_PATH_DOMAIN_CPU_O, name, i);
+ if (mkfifo(fifo_in, 0644) < 0) {
+ if (errno != EEXIST)
+ pdie("mkfifo %s", fifo_in);
+ }
+ if (mkfifo(fifo_out, 0644) < 0) {
+ if (errno != EEXIST)
+ pdie("mkfifo %s", fifo_out);
+ }
}
- chmod(VIRT_DIR, 0710);
- if (chown(VIRT_DIR, -1, group->gr_gid) < 0)
- pdie("chown %s", VIRT_DIR);
+ plog("CPUS: %d\n", cpu);
+}
+
+static void make_domain_dirs(void)
+{
+ struct domain_dir *dom_dir;
+ char gr_name[5] = "qemu";
+ char buf[PATH_MAX];
+ mode_t perms;
+
+ for_each_domain(dom_dir) {
+ snprintf(buf, PATH_MAX, VIRT_DOMAIN_DIR, dom_dir->name);
+
+ if (dom_dir->perms)
+ perms = dom_dir->perms;
+ else
+ perms = 0710;
+
+ if (dom_dir->group)
+ make_dir_virt(buf, perms, dom_dir->group);
+ else
+ make_dir_virt(buf, perms, gr_name);
+
+ plog("---\n"
+ "Process Directory: %s\n"
+ "Directory permission: %o\n"
+ "Group: %s\n", buf, perms, dom_dir->group ? dom_dir->group : gr_name);
+
+ if (dom_dir->cpu)
+ make_traceif_in_dom_dir(dom_dir->name, dom_dir->cpu);
+ }
+
+ plog("---\n");
+ free(dom_dir_list);
+}
+
+static void make_virt_if_dir(void)
+{
+ char gr_name[5] = "qemu";
+
+ /* QEMU operates as qemu:qemu */
+ make_dir_virt(TRACE_CMD_DIR, 0710, gr_name);
+ make_dir_virt(VIRT_DIR, 0710, gr_name);
+
+ if (dom_dir_list)
+ make_domain_dirs();
}

static void do_listen_virt(void)
@@ -1057,7 +1131,14 @@ static void start_daemon(void)
die("starting daemon");
}

+static void add_dom_dir(struct domain_dir *dom_dir)
+{
+ dom_dir->next = dom_dir_list;
+ dom_dir_list = dom_dir;
+}
+
enum {
+ OPT_dom = 254,
OPT_debug = 255,
};

@@ -1072,6 +1153,37 @@ static void parse_args_net(int c, char **argv, char **port)
}
}

+static void parse_args_virt(int c, char **argv)
+{
+ static struct domain_dir *dom_dir;
+
+ switch (c) {
+ case 'm':
+ if (!dom_dir)
+ die("-m needs --dom <domain>");
+ dom_dir->perms = strtol(optarg, NULL, 8);
+ break;
+ case 'g':
+ if (!dom_dir)
+ die("-g needs --dom <domain>");
+ dom_dir->group = optarg;
+ break;
+ case 'c':
+ if (!dom_dir)
+ die("-c needs --dom <domain>");
+ dom_dir->cpu = atoi(optarg);
+ break;
+ case OPT_dom:
+ dom_dir = malloc_or_die(sizeof(*dom_dir));
+ memset(dom_dir, 0, sizeof(*dom_dir));
+ dom_dir->name = optarg;
+ add_dom_dir(dom_dir);
+ break;
+ default:
+ usage(argv);
+ }
+}
+
void trace_listen(int argc, char **argv)
{
char *logfile = NULL;
@@ -1094,12 +1206,13 @@ void trace_listen(int argc, char **argv)
int option_index = 0;
static struct option long_options[] = {
{"port", required_argument, NULL, 'p'},
+ {"dom", required_argument, NULL, OPT_dom},
{"help", no_argument, NULL, '?'},
{"debug", no_argument, NULL, OPT_debug},
{NULL, 0, NULL, 0}
};

- c = getopt_long (argc-1, argv+1, "+hp:o:d:l:D",
+ c = getopt_long (argc-1, argv+1, "+hp:o:d:l:Dm:g:c:",
long_options, &option_index);
if (c == -1)
break;
@@ -1125,12 +1238,14 @@ void trace_listen(int argc, char **argv)
default:
if (mode == NET)
parse_args_net(c, argv, &port);
+ else if (mode == VIRT)
+ parse_args_virt(c, argv);
else
usage(argv);
}
}

- if (!port && mode == NET)
+ if (!port && (mode == NET))
usage(argv);

if ((argc - optind) >= 2)
diff --git a/trace-usage.c b/trace-usage.c
index 0411cb4..f96a5ba 100644
--- a/trace-usage.c
+++ b/trace-usage.c
@@ -186,11 +186,16 @@ static struct usage_help usage_help[] = {
"virt-server",
"listen on a virtio-serial for trace clients",
" %s virt-server [-o file][-d dir][-l logfile]\n"
+ " [--dom domain [-m permisson] [-g group] [-c cpu]]\n"
" Creates a socket to listen for clients.\n"
" -D create it in daemon mode.\n"
" -o file name to use for clients.\n"
" -d diretory to store client files.\n"
" -l logfile to write messages to.\n"
+ " --dom create domain direcroty in /tmp/trace-cmd/virt and folling directory permissions/group names and FIFO files will be changed here\n"
+ " -m changes the permission of domain directory.\n"
+ " -g changes group of domain directory.\n"
+ " -c creates trace data I/F(trace-path-cpu*.{in, out} files) in domain directory.\n"
},
{
"list",

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