qemu_hotplug: don't forget to add hostdev interfaces to the interface list

Originally qemuDomainAttachNetDevice() would wait until the cleanup at
the very end of the function to add newly hotplugged interfaces to the
domain's nets list. commit 7b8bec4560 modified it to add the new
interface to the nets list earlier (but not all the way at the
beginning of the function either, because there are some operations
(PCI address assignment in particular) that need the new device to not
yet be visible in the domaindef).

But hostdev interfaces short-circuit past most of the body of
qemuDomainAttachNetDevice() (since none of it applies to hostdev
interfaces). In the past that was okay, but since the line that adds
the new interface to the domaindef's nets list is in that "most of the
body", after that commit hotplugged hostdev interfaces are no longer
being properly added to the domaindef nets list, so they don't show up
in the status XML or the virsh domiflist output.

It really *is* important to add interfaces to the nets list earlier,
so we can't revert commit 7b8bec4560, and we also can't move the
insert to common code *earlier* in the function, so instead this patch
duplicates the VIR_APPEND_ELEMENT_COPY() just before the code path for
hostdev interfaces jumps to cleanup.

Resolves: https://bugzilla.redhat.com/1972468
Fixes: 7b8bec45601b6570f6a7413e94d291986d2663f1
Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index ddc797afaef8cef40fb419989e9419dc2df40452..d2a354d026c7ce18cf0ce8020488d752948cdcea 100644 (file)
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -1230,10 +1230,21 @@ qemuDomainAttachNetDevice(virQEMUDriver *driver,
         /* This is really a "smart hostdev", so it should be attached
          * as a hostdev (the hostdev code will reach over into the
          * netdev-specific code as appropriate), then also added to
-         * the nets list (see cleanup:) if successful.
+         * the nets list if successful.
          */
-        ret = qemuDomainAttachHostDevice(driver, vm,
-                                         virDomainNetGetActualHostdev(net));
+        if (qemuDomainAttachHostDevice(driver, vm,
+                                       virDomainNetGetActualHostdev(net)) < 0) {
+            goto cleanup;
+        }
+        if (VIR_APPEND_ELEMENT_COPY(vm->def->nets, vm->def->nnets, net) < 0)
+            goto cleanup;
+
+        /* the rest of the setup doesn't apply to hostdev interfaces, so
+         * we can skip straight to the cleanup (nothing there applies to
+         * hostdev interfaces either, but it might in the future, so we
+         * may as well be consistent)
+         */
+        ret = 0;
         goto cleanup;
     }