[PATCH 10/28] libxl: kill_device_model: Silently tolerate ENOENT on pid xs path

[Ian Jackson <ian.jackson@eu.citrix.com>]

If the pid is absent in xenstore, this means there is no such DM.  Do
not complain about this, then.  This allows us to simplify call sites.
Do so for libxl__destroy_domid.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
---
v6: New patch.
---
 tools/libxl/libxl.c    |    4 +---
 tools/libxl/libxl_dm.c |    7 ++++++-
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index 5414649..2a0c092 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -1606,7 +1606,6 @@ void libxl__destroy_domid(libxl__egc *egc, libxl__destroy_domid_state *dis)
     libxl_ctx *ctx = CTX;
     uint32_t domid = dis->domid;
     char *dom_path;
-    char *pid;
     int rc, dm_present;
 
     libxl__ev_child_init(&dis->destroyer);
@@ -1642,8 +1641,7 @@ void libxl__destroy_domid(libxl__egc *egc, libxl__destroy_domid_state *dis)
         }
         /* fall through */
     case LIBXL_DOMAIN_TYPE_PV:
-        pid = libxl__xs_read(gc, XBT_NULL, GCSPRINTF("/local/domain/%d/image/device-model-pid", domid));
-        dm_present = (pid != NULL);
+        dm_present = 1;
         break;
     case LIBXL_DOMAIN_TYPE_INVALID:
         rc = ERROR_FAIL;
diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c
index b85b377..593f3e6 100644
--- a/tools/libxl/libxl_dm.c
+++ b/tools/libxl/libxl_dm.c
@@ -2053,11 +2053,16 @@ static int kill_device_model(libxl__gc *gc, const char *xs_path_pid)
     int ret, pid;
 
     ret = libxl__xs_read_checked(gc, XBT_NULL, xs_path_pid, &xs_pid);
-    if (ret || !xs_pid) {
+    if (ret) {
         LOG(ERROR, "unable to find device model pid in %s", xs_path_pid);
         ret = ret ? : ERROR_FAIL;
         goto out;
     }
+    if (!xs_pid) {
+        /* Jolly good */
+        ret = 0;
+        goto out;
+    }
     pid = atoi(xs_pid);
 
     ret = kill(pid, SIGHUP);
-- 
1.7.10.4