[libvirt] [PATCH] docs: document dxml argument to migrate2

[Eric Blake]

Commit 135554166 introduced a nice feature without documenting it.

* src/libvirt.c (virDomainMigrate2): Add paragraph.
---
 src/libvirt.c |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/src/libvirt.c b/src/libvirt.c
index fc17f2b..13da214 100644
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -4297,6 +4297,15 @@ error:
  * different processors even with the same architecture, or between
  * different types of hypervisor.
  *
+ * If the hypervisor supports it, @dxml can be used to alter
+ * host-specific portions of the domain XML that will be used on
+ * the destination.  For example, it is possible to alter the
+ * backing filename that is associated with a disk device, in order
+ * to account for naming differences between source and destination
+ * in accessing the underlying storage.  The migration will fail
+ * if @dxml would cause any guest-visible changes.  Pass NULL
+ * if no changes are needed to the XML between source and destination.
+ *
  * Returns the new domain object if the migration was successful,
  *   or NULL in case of error.  Note that the new domain object
  *   exists in the scope of the destination connection (dconn).
-- 
1.7.4.4