diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index 3f7f87524a..1bbece0e52 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -5215,6 +5215,25 @@ qemu-kvm -net nic,model=? /dev/null Since 0.9.5

+
MTU configuration
+
+...
+<devices>
+  <interface type='network'>
+    <source network='default'/>
+    <target dev='vnet0'/>
+    <mtu size='1500'/>
+  </interface>
+</devices>
+...
+ +

+ This element provides means of setting MTU of the virtual network link. + Currently there is just one attribute size which accepts a + non-negative integer which specifies the MTU size for the interface. + Since 3.1.0 +

+
IP configuration
 ...
diff --git a/docs/news.xml b/docs/news.xml
index ef7e2db861..fdbb80f441 100644
--- a/docs/news.xml
+++ b/docs/news.xml
@@ -24,6 +24,14 @@
           options in order to print just the --name and/or --uuid of pools.
         
       
+      
+        
+          Introduce MTU to domain <interface/>
+        
+        
+          Allow setting MTU size for some types of domain interface.
+        
+      
     
     

       
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index 4d76315b09..cc6e0d0c0d 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -2465,6 +2465,9 @@
           
         
       
+      
+        
+      
       
         
           
diff --git a/docs/schemas/networkcommon.rng b/docs/schemas/networkcommon.rng
index a334b83e3b..26995556d4 100644
--- a/docs/schemas/networkcommon.rng
+++ b/docs/schemas/networkcommon.rng
@@ -260,10 +260,19 @@
       
     
   
+
   
     
       kernel
       libvirt
     
   
+
+  
+    
+      
+        
+      
+    
+  
 
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 26bb0fdd0a..a2b72cb9c5 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -10050,6 +10050,12 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
         goto error;
     }
 
+    if (virXPathUInt("string(./mtu/@size)", ctxt, &def->mtu) < -1) {
+        virReportError(VIR_ERR_XML_ERROR, "%s",
+                       _("malformed mtu size"));
+        goto error;
+    }
+
  cleanup:
     ctxt->node = oldnode;
     VIR_FREE(macaddr);
@@ -21769,6 +21775,10 @@ virDomainNetDefFormat(virBufferPtr buf,
         virBufferAsprintf(buf, "\n",
                           virDomainNetInterfaceLinkStateTypeToString(def->linkstate));
     }
+
+    if (def->mtu)
+        virBufferAsprintf(buf, "\n", def->mtu);
+
     if (virDomainDeviceInfoFormat(buf, &def->info,
                                   flags | VIR_DOMAIN_DEF_FORMAT_ALLOW_BOOT
                                   | VIR_DOMAIN_DEF_FORMAT_ALLOW_ROM) < 0)
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 78a3db4e12..4d830c51d4 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -1009,6 +1009,7 @@ struct _virDomainNetDef {
     virNetDevVlan vlan;
     int trustGuestRxFilters; /* enum virTristateBool */
     int linkstate;
+    unsigned int mtu;
 };
 
 /* Used for prefix of ifname of any network name generated dynamically
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 2ed45ab176..26ca899306 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -2868,6 +2868,14 @@ qemuDomainDeviceDefValidate(const virDomainDeviceDef *dev,
                            _("rx_queue_size has to be a power of two"));
             goto cleanup;
         }
+
+        if (net->mtu &&
+            !qemuDomainNetSupportsMTU(net->type)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                           _("setting MTU on interface type %s is not supported yet"),
+                           virDomainNetTypeToString(net->type));
+            goto cleanup;
+        }
     }
 
     ret = 0;
@@ -6529,6 +6537,27 @@ qemuDomainSupportsNetdev(virDomainDefPtr def,
     return virQEMUCapsGet(qemuCaps, QEMU_CAPS_NETDEV);
 }
 
+bool
+qemuDomainNetSupportsMTU(virDomainNetType type)
+{
+    switch (type) {
+    case VIR_DOMAIN_NET_TYPE_USER:
+    case VIR_DOMAIN_NET_TYPE_ETHERNET:
+    case VIR_DOMAIN_NET_TYPE_VHOSTUSER:
+    case VIR_DOMAIN_NET_TYPE_SERVER:
+    case VIR_DOMAIN_NET_TYPE_CLIENT:
+    case VIR_DOMAIN_NET_TYPE_MCAST:
+    case VIR_DOMAIN_NET_TYPE_NETWORK:
+    case VIR_DOMAIN_NET_TYPE_BRIDGE:
+    case VIR_DOMAIN_NET_TYPE_INTERNAL:
+    case VIR_DOMAIN_NET_TYPE_DIRECT:
+    case VIR_DOMAIN_NET_TYPE_HOSTDEV:
+    case VIR_DOMAIN_NET_TYPE_UDP:
+    case VIR_DOMAIN_NET_TYPE_LAST:
+        break;
+    }
+    return false;
+}
 
 int
 qemuDomainNetVLAN(virDomainNetDefPtr def)
diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h
index 88b5869725..041149167c 100644
--- a/src/qemu/qemu_domain.h
+++ b/src/qemu/qemu_domain.h
@@ -708,6 +708,8 @@ bool qemuDomainSupportsNetdev(virDomainDefPtr def,
                               virQEMUCapsPtr qemuCaps,
                               virDomainNetDefPtr net);
 
+bool qemuDomainNetSupportsMTU(virDomainNetType type);
+
 int qemuDomainNetVLAN(virDomainNetDefPtr def);
 
 int qemuDomainSetPrivatePaths(virQEMUDriverPtr driver,
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-net-mtu.xml b/tests/qemuxml2argvdata/qemuxml2argv-net-mtu.xml
new file mode 100644
index 0000000000..6063224633
--- /dev/null
+++ b/tests/qemuxml2argvdata/qemuxml2argv-net-mtu.xml
@@ -0,0 +1,60 @@
+
+  test
+  15d091de-0181-456b-9554-e4382dc1f1ab
+  1048576
+  1048576
+  1
+  
+    hvm
+    
+    
+    
+  
+  
+  destroy
+  restart
+  restart
+  
+    /usr/bin/qemu
+    
+      
+      
+      
+      

+    
+    
+      
+      
+      
+      
+      

+    
+    
+    
+      

+    
+    
+    
+    
+      
+      
+      
+      
+    
+    
+      
+      
+      
+      
+    
+    
+      
+    
+    
+      
+    
+    
+    
+    
+  
+