guestfs: don't fault upon failed vasprintf

[libguestfs.git] / src / guestfs.c

diff --git a/src/guestfs.c b/src/guestfs.c
index 386dee6..802c1d2 100644 (file)
--- a/src/guestfs.c
+++ b/src/guestfs.c
@@ -443,9 +443,11 @@ guestfs_perrorf (guestfs_h *g, const char *fs, ...)
   int err = errno;
 
   va_start (args, fs);
-  vasprintf (&msg, fs, args);
+  int err = vasprintf (&msg, fs, args);
   va_end (args);
 
+  if (err < 0) return;
+
 #ifndef _GNU_SOURCE
   char buf[256];
   strerror_r (err, buf, sizeof buf);
@@ -1038,14 +1040,18 @@ guestfs_launch (guestfs_h *g)
      */
     g->cmdline[0] = g->qemu;
 
-    /* Construct the -net channel parameter for qemu. */
-    snprintf (vmchannel, sizeof vmchannel,
-             "channel,%d:unix:%s,server,nowait",
-             VMCHANNEL_PORT, unixsock);
+#define LINUX_CMDLINE                                                  \
+    "panic=1 "         /* force kernel to panic if daemon exits */     \
+    "console=ttyS0 "   /* serial console */                            \
+    "udevtimeout=300 " /* good for very slow systems (RHBZ#480319) */  \
+    "noapic "          /* workaround for RHBZ#502058 - ok if not SMP */ \
+    "acpi=off "        /* we don't need ACPI, turn it off */           \
+    "cgroup_disable=memory " /* saves us about 5 MB of RAM */           \
+    "selinux=0 "       /* SELinux is messed up if there's no policy */
 
     /* Linux kernel command line. */
     snprintf (append, sizeof append,
-             "panic=1 console=ttyS0 guestfs=%s:%d%s%s%s",
+             LINUX_CMDLINE "guestfs=%s:%d%s%s%s",
              VMCHANNEL_ADDR, VMCHANNEL_PORT,
              g->verbose ? " guestfs_verbose=1" : "",
              g->append ? " " : "", g->append ? g->append : "");
@@ -1064,10 +1070,38 @@ guestfs_launch (guestfs_h *g)
     add_cmdline (g, "-nographic");
     add_cmdline (g, "-serial");
     add_cmdline (g, "stdio");
-    add_cmdline (g, "-net");
-    add_cmdline (g, vmchannel);
-    add_cmdline (g, "-net");
-    add_cmdline (g, "user,vlan=0");
+
+#if 0
+    /* Doesn't work.  See:
+     * http://lists.gnu.org/archive/html/qemu-devel/2009-07/threads.html
+     * Subject "guestfwd option doesn't allow supplementary ,server,nowait"
+     */
+    if (qemu_supports (g, "guestfwd")) {
+      /* New-style -net user,guestfwd=... syntax for vmchannel.  See:
+       * http://git.savannah.gnu.org/cgit/qemu.git/commit/?id=c92ef6a22d3c71538fcc48fb61ad353f7ba03b62
+       */
+      snprintf (vmchannel, sizeof vmchannel,
+               "user,vlan=0,guestfwd=tcp:%s:%d-unix:%s,server,nowait",
+               VMCHANNEL_ADDR, VMCHANNEL_PORT, unixsock);
+
+      add_cmdline (g, "-net");
+      add_cmdline (g, vmchannel);
+    } else {
+#endif
+      /* Not guestfwd.  HOPEFULLY this qemu uses the older -net channel
+       * syntax, or if not then we'll get a quick failure.
+       */
+      snprintf (vmchannel, sizeof vmchannel,
+               "channel,%d:unix:%s,server,nowait",
+               VMCHANNEL_PORT, unixsock);
+
+      add_cmdline (g, "-net");
+      add_cmdline (g, vmchannel);
+      add_cmdline (g, "-net");
+      add_cmdline (g, "user,vlan=0");
+#if 0
+    }
+#endif
     add_cmdline (g, "-net");
     add_cmdline (g, "nic,model=virtio,vlan=0");