This patch adds a flag for attaching the newly created FIFOs for guest tracing
as virtio serial devices to libvirt managed guests.
Signed-off-by: Slavomir Kaslev <kaslevs@xxxxxxxxxx>
---
tracecmd/trace-setup-guest.c | 54 ++++++++++++++++++++++++++++++++++--
tracecmd/trace-usage.c | 3 +-
2 files changed, 53 insertions(+), 4 deletions(-)
diff --git a/tracecmd/trace-setup-guest.c b/tracecmd/trace-setup-guest.c
index a55a37d..ae2fecb 100644
--- a/tracecmd/trace-setup-guest.c
+++ b/tracecmd/trace-setup-guest.c
@@ -111,7 +111,45 @@ static int get_guest_cpu_count(const char *guest)
return nr_cpus;
}
-static void do_setup_guest(const char *guest, int nr_cpus, mode_t mode, gid_t gid)
+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 = -errno;
+ 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, bool attach)
{
gid_t save_egid;
int ret;
@@ -131,6 +169,12 @@ 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);
+ if (attach) {
+ ret = attach_guest_fifos(guest, nr_cpus);
+ if (ret < 0)
+ pdie("failed to attach FIFOs to %s", guest);
+ }
+
if (gid != -1) {
ret = setegid(save_egid);
if (ret < 0)
@@ -140,6 +184,7 @@ static void do_setup_guest(const char *guest, int nr_cpus, mode_t mode, gid_t gi
void trace_setup_guest(int argc, char **argv)
{
+ bool attach = false;
struct group *group;
mode_t mode = 0660;
int nr_cpus = -1;
@@ -159,7 +204,7 @@ void trace_setup_guest(int argc, char **argv)
{NULL, 0, NULL, 0}
};
- c = getopt_long(argc-1, argv+1, "+hc:p:g:",
+ c = getopt_long(argc-1, argv+1, "+hc:p:g:a",
long_options, &option_index);
if (c == -1)
break;
@@ -179,6 +224,9 @@ void trace_setup_guest(int argc, char **argv)
pdie("group %s does not exist", optarg);
gid = group->gr_gid;
break;
+ case 'a':
+ attach = true;
+ break;
default:
usage(argv);
}
@@ -195,5 +243,5 @@ void trace_setup_guest(int argc, char **argv)
if (nr_cpus <= 0)
pdie("invalid number of cpus for guest %s", guest);
- do_setup_guest(guest, nr_cpus, mode, gid);
+ do_setup_guest(guest, nr_cpus, mode, gid, attach);
}
diff --git a/tracecmd/trace-usage.c b/tracecmd/trace-usage.c
index 9a13d93..bcfd3dc 100644
--- a/tracecmd/trace-usage.c
+++ b/tracecmd/trace-usage.c
@@ -249,10 +249,11 @@ 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][-a] guest\n"
" -c number of guest virtual CPUs\n"
" -p FIFOs permissions (default: 0660)\n"
" -g FIFOs group owner\n"
+ " -a Attach FIFOs to guest VM config\n"
},
#endif
{
--
2.19.1
|