[PATCH v2 2/5] qemu_passt: Report passt's error on failed start

[Michal Privoznik <mprivozn@redhat.com>]

When starting passt, it may write something onto its stderr
(convincing it to print even more is addressed later). Pass this
string we read to user.

Since we're not daemonizing passt anymore (see previous commit),
we can let virCommand module do all the heavy lifting and switch
to virCommandSetErrorBuffer() instead of reading error from an
FD.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
---
 src/qemu/qemu_passt.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/qemu/qemu_passt.c b/src/qemu/qemu_passt.c
index adc69fc052..c082c149cd 100644
--- a/src/qemu/qemu_passt.c
+++ b/src/qemu/qemu_passt.c
@@ -144,18 +144,18 @@ qemuPasstStart(virDomainObj *vm,
     g_autofree char *passtSocketName = qemuPasstCreateSocketPath(vm, net);
     g_autoptr(virCommand) cmd = NULL;
     g_autofree char *pidfile = qemuPasstCreatePidFilename(vm, net);
+    g_autofree char *errbuf = NULL;
     char macaddr[VIR_MAC_STRING_BUFLEN];
     size_t i;
     pid_t pid = (pid_t) -1;
     int exitstatus = 0;
     int cmdret = 0;
-    VIR_AUTOCLOSE errfd = -1;
 
     cmd = virCommandNew(PASST);
 
     virCommandClearCaps(cmd);
     virCommandSetPidFile(cmd, pidfile);
-    virCommandSetErrorFD(cmd, &errfd);
+    virCommandSetErrorBuffer(cmd, &errbuf);
 
     virCommandAddArgList(cmd,
                          "--one-off",
@@ -266,7 +266,7 @@ qemuPasstStart(virDomainObj *vm,
 
     if (cmdret < 0 || exitstatus != 0) {
         virReportError(VIR_ERR_INTERNAL_ERROR,
-                       _("Could not start 'passt'. exitstatus: %d"), exitstatus);
+                       _("Could not start 'passt': %s"), NULLSTR(errbuf));
         goto error;
     }
 
-- 
@@ -144,18 +144,18 @@ qemuPasstStart(virDomainObj *vm,
     g_autofree char *passtSocketName = qemuPasstCreateSocketPath(vm, net);
     g_autoptr(virCommand) cmd = NULL;
     g_autofree char *pidfile = qemuPasstCreatePidFilename(vm, net);
+    g_autofree char *errbuf = NULL;
     char macaddr[VIR_MAC_STRING_BUFLEN];
     size_t i;
     pid_t pid = (pid_t) -1;
     int exitstatus = 0;
     int cmdret = 0;
-    VIR_AUTOCLOSE errfd = -1;
 
     cmd = virCommandNew(PASST);
 
     virCommandClearCaps(cmd);
     virCommandSetPidFile(cmd, pidfile);
-    virCommandSetErrorFD(cmd, &errfd);
+    virCommandSetErrorBuffer(cmd, &errbuf);
 
     virCommandAddArgList(cmd,
                          "--one-off",
@@ -266,7 +266,7 @@ qemuPasstStart(virDomainObj *vm,
 
     if (cmdret < 0 || exitstatus != 0) {
         virReportError(VIR_ERR_INTERNAL_ERROR,
-                       _("Could not start 'passt'. exitstatus: %d"), exitstatus);
+                       _("Could not start 'passt': %s"), NULLSTR(errbuf));
         goto error;
     }
 
-- 
2.39.1