qemu_hotplug: don't call DetachThisHostDevice for hostdev network devices

Back in the bad old days different device types required a different
qemu monitor call to detach them, and so an <interface type='hostdev'>
needed to call the function for detaching hostdevs, while other
<interface> types could be deleted as netdevs.

Times have changed, and *all* device types are detached by calling the
common function qemuDomainDeleteDevice(vm, alias), so we don't need to
differentiate between hostdev interfaces and the others for that
reason.

There are a few other netdev-specific functions called during
qemuDomainDetachNetDevice() (clearing bandwidth limits, stopping the
interface), but those turn into NOPs when type=hostdev, so they're
safe to call for type=hostdev.

The only thing that is different + not a NOP is the call to
virDomainAudit*() when qemuDomainDeleteDevice() fails, so if we add a
conditional for that small bit of code, we can eliminate the callout
from qemuDomainDetachNetDevice() to qemuDomainDetachThisDevice(),
which makes this function fit the desired pattern for merging with the
other detach functions, and paves the way to simplifying
qemuDomainDetachHostDevice() too.
Signed-off-by: NLaine Stump <laine@laine.org>
ACKed-by: NPeter Krempa <pkrempa@redhat.com>

src/qemu/qemu_hotplug.c

@@ -5798,13 +5798,6 @@ qemuDomainDetachNetDevice(virQEMUDriverPtr driver,
 
     detach = vm->def->nets[detachidx];
 
-    if (virDomainNetGetActualType(detach) == VIR_DOMAIN_NET_TYPE_HOSTDEV) {
-        ret = qemuDomainDetachThisHostDevice(driver, vm,
-                                             virDomainNetGetActualHostdev(detach),
-                                             async);
-        goto cleanup;
-    }
-
     if (qemuIsMultiFunctionDevice(vm->def, &detach->info)) {
         virReportError(VIR_ERR_OPERATION_FAILED,
                        _("cannot hot unplug multifunction PCI device: %s"),
@@ -5833,8 +5826,13 @@ qemuDomainDetachNetDevice(virQEMUDriverPtr driver,
         qemuDomainMarkDeviceForRemoval(vm, &detach->info);
 
     if (qemuDomainDeleteDevice(vm, detach->info.alias) < 0) {
-        if (virDomainObjIsActive(vm))
-            virDomainAuditNet(vm, detach, NULL, "detach", false);
+        if (virDomainObjIsActive(vm)) {
+            /* the audit message has a different format for hostdev network devices */
+            if (virDomainNetGetActualType(detach) == VIR_DOMAIN_NET_TYPE_HOSTDEV)
+                virDomainAuditHostdev(vm, virDomainNetGetActualHostdev(detach), "detach", false);
+            else
+                virDomainAuditNet(vm, detach, NULL, "detach", false);
+        }
         goto cleanup;
     }