Libguestfs - Mar 2014 - [PATCH 2/2] launch: libvirt: Use libvirt to set up the user network.

Use libvirt to set up the user network instead of a custom qemu
argument.

Note this requires a non-upstream patch being discussed on the libvirt
mailing list at the moment.

https://bugzilla.redhat.com/show_bug.cgi?id=1075520#c6

Rich.

This lets us generate XML conditionally based on libvirt version.
---
 src/launch-libvirt.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/launch-libvirt.c b/src/launch-libvirt.c
index e4563f8..7653bf9 100644
--- a/src/launch-libvirt.c
+++ b/src/launch-libvirt.c
@@ -100,6 +100,7 @@ xmlBufferDetach (xmlBufferPtr buf)
 
 /* Per-handle data. */
 struct backend_libvirt_data {
+  unsigned long version;        /* libvirt version */
   virConnectPtr conn;           /* libvirt connection */
   virDomainPtr dom;             /* libvirt domain */
   char *selinux_label;
@@ -208,7 +209,6 @@ launch_libvirt (guestfs_h *g, void *datav, const char
*libvirt_uri)
 {
   struct backend_libvirt_data *data = datav;
   int daemon_accept_sock = -1, console_sock = -1;
-  unsigned long version;
   virConnectPtr conn = NULL;
   virDomainPtr dom = NULL;
   CLEANUP_FREE char *capabilities_xml = NULL;
@@ -234,11 +234,13 @@ launch_libvirt (guestfs_h *g, void *datav, const char
*libvirt_uri)
     return -1;
   }
 
-  virGetVersion (&version, NULL, NULL);
+  virGetVersion (&data->version, NULL, NULL);
   debug (g, "libvirt version = %lu (%lu.%lu.%lu)",
-         version,
-         version / 1000000UL, version / 1000UL % 1000UL, version % 1000UL);
-  if (version < MIN_LIBVIRT_VERSION) {
+         data->version,
+         data->version / 1000000UL,
+         data->version / 1000UL % 1000UL,
+         data->version % 1000UL);
+  if (data->version < MIN_LIBVIRT_VERSION) {
     error (g, _("you must have libvirt >= %d.%d.%d "
                 "to use the 'libvirt' backend"),
            MIN_LIBVIRT_MAJOR, MIN_LIBVIRT_MINOR, MIN_LIBVIRT_MICRO);
-- 
1.8.5.3

This only works in libvirt >= 1.3.0.  See:
https://bugzilla.redhat.com/show_bug.cgi?id=1075520

Thanks: Michal Privoznik
---
 src/launch-libvirt.c | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/src/launch-libvirt.c b/src/launch-libvirt.c
index 7653bf9..87ad21a 100644
--- a/src/launch-libvirt.c
+++ b/src/launch-libvirt.c
@@ -1210,6 +1210,20 @@ construct_libvirt_xml_devices (guestfs_h *g,
       } end_element ();
     } end_element ();
 
+    /* User network using libvirt >= 1.3.0. */
+    if (params->data->version >= 1003000 &&
g->enable_network) {
+      start_element ("interface") {
+        attribute ("type", "user");
+        start_element ("ip") {
+          attribute ("address", "169.254.0.0");
+          attribute ("prefix", "16");
+        } end_element ();
+        start_element ("model") {
+          attribute ("type", VIRTIO_NET);
+        } end_element ();
+      } end_element ();
+    }
+
   } end_element (); /* </devices> */
 
   return 0;
@@ -1588,10 +1602,11 @@ construct_libvirt_xml_qemu_cmdline (guestfs_h *g,
       attribute ("value", tmpdir);
     } end_element ();
 
-    /* Workaround because libvirt user networking cannot specify
"net="
-     * parameter.
+    /* Workaround because libvirt user networking cannot specify
+     * "net=" parameter.  We can remove this when the min required
+     * libvirt version is >= 1.3.0.
      */
-    if (g->enable_network) {
+    if (params->data->version < 1003000 &&
g->enable_network) {
       start_element ("qemu:arg") {
         attribute ("value", "-netdev");
       } end_element ();
-- 
1.8.5.3

On Thu, Mar 27, 2014 at 06:47:55PM +0000, Richard W.M. Jones
wrote:
> This only works in libvirt >= 1.3.0.  See:
The release we're about todo is 1.2.3, and it isn't clear if
we'll go to 1.2.4 or 1.3.0 yet - probably the former at this
point.

Regards,
Daniel
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