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@xxxxxxxxxx>
---
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
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