From 78a9316063050d84b39324470102330a89a1f76b Mon Sep 17 00:00:00 2001
Message-Id: <78a9316063050d84b39324470102330a89a1f76b@dist-git>
From: Michal Privoznik <mprivozn@redhat.com>
Date: Thu, 16 Feb 2023 12:19:26 +0100
Subject: [PATCH] qemu_passt: Report passt's error on failed start

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.

Resolves: https://bugzilla.redhat.com/2169244

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Laine Stump <laine@redhat.com>
(cherry picked from commit 02355840ced2af18df1aa9ba387a6137a515eede)
Signed-off-by: Laine Stump <laine@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;
     }
 
-- 
2.39.2