qemu: fail on attempt to set 'floor' if interface type is not 'network'

QoS 'floor' setting is documented to be only supported for interfaces of
type 'network'.  Fail with an error message on attempt to set 'floor' on
an interface of any other type.
Signed-off-by: NPavel Mores <pmores@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

src/qemu/qemu_driver.c

@@ -11672,9 +11672,21 @@ qemuDomainSetInterfaceParameters(virDomainPtr dom,
                    sizeof(*newBandwidth->out));
         }
 
-        if (net->type == VIR_DOMAIN_NET_TYPE_NETWORK &&
-            virDomainNetBandwidthUpdate(net, newBandwidth) < 0)
-            goto endjob;
+        if (net->type == VIR_DOMAIN_NET_TYPE_NETWORK) {
+            if (virDomainNetBandwidthUpdate(net, newBandwidth) < 0)
+                goto endjob;
+        } else {
+            if (virNetDevBandwidthHasFloor(bandwidth)) {
+                char ifmac[VIR_MAC_STRING_BUFLEN];
+
+                virMacAddrFormat(&net->mac, ifmac);
+                virReportError(VIR_ERR_OPERATION_UNSUPPORTED,
+                               _("Invalid use of 'floor' on interface with MAC address %s "
+                               "- 'floor' is only supported for interface type 'network' with forward type 'nat', 'route', 'open' or none"),
+                               ifmac);
+                goto endjob;
+            }
+        }
 
         if (virNetDevBandwidthSet(net->ifname, newBandwidth, false,
                                   !virDomainNetTypeSharesHostView(net)) < 0) {