qemu: fix regression in update-device for interfaces

Commit a37bd2a15b8f2e7aa09519c86fe1ba1e59ce113f eliminated a failure
to update *any* change in an interface that was connected via a
network that consisted of a pool of VFs using macvtap passthrough
mode. Unfortunately it caused a regression that results in failure to
update changes to bandwidth/vlan/trustGuestRxFilters in any interface
connected via a network that uses a bridge to connect tap devices.

This fixes that problem by narrowing the usage of the fix in the
earlier patch to only be done in the case that the the interface is
connected via a macvtap+passthrough network.

Signed-off-by: Laine Stump <laine@redhat.com>
Fixes: a37bd2a15b8f2e7aa09519c86fe1ba1e59ce113f
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>

diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index 09a37caf85c3a594d699847b2ce080a6e993ebf6..4d4bcde1bc184ed3206f568ca30fb3033914fb09 100644 (file)
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -3918,12 +3918,19 @@ qemuDomainChangeNet(virQEMUDriver *driver,
      * free it if we fail for any reason
      */
     if (newdev->type == VIR_DOMAIN_NET_TYPE_NETWORK) {
-        if (olddev->type == VIR_DOMAIN_NET_TYPE_NETWORK
-            && STREQ(olddev->data.network.name, newdev->data.network.name)) {
+        if (olddev->type == VIR_DOMAIN_NET_TYPE_NETWORK &&
+            oldType == VIR_DOMAIN_NET_TYPE_DIRECT &&
+            virDomainNetGetActualDirectMode(olddev) == VIR_NETDEV_MACVLAN_MODE_PASSTHRU &&
+            STREQ(olddev->data.network.name, newdev->data.network.name)) {
             /* old and new are type='network', and the network name
-             * hasn't changed. In this case we *don't* want to get a
-             * new port ("actual device") from the network because we
-             * can use the old one (since it hasn't changed).
+             * hasn't changed *and* this is a network where each
+             * connection is allocated exclusive use of a VF
+             * device. In this case we *don't* want to get a new port
+             * ("actual device") from the network because attempting
+             * to allocate a new device would also allocate a
+             * new/different VF, causing the update to fail. And
+             * anyway we can use olddev's actualNetDef (since it
+             * hasn't changed).
              *
              * So instead we just duplicate *the pointer to* the
              * actualNetDef from olddev to newdev so that comparisons