conf: support backend domain name in disk and network devices

At least Xen supports backend drivers in another domain (aka "driver
domain"). This patch introduces an XML config option for specifying the
backend domain name for <disk> and <interface> devices.  E.g.

  <disk>
    <backenddomain name='diskvm'/>
    ...
  </disk>
  <interface type='bridge'>
    <backenddomain name='netvm'/>
    ...
  </interface>

In the future, same option will be needed for USB devices (hostdev
objects), but for now libxl doesn't have support for PVUSB.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>

diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index f6477c28d4e079424d30480438fa879d8d0fc6ad..fb0a0d14c94bad7532a9c99f8fd2934a18305d5e 100644 (file)
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -2372,6 +2372,12 @@
           </li>
         </ul>
       </dd>
+      <dt><code>backenddomain</code></dt>
+      <dd>The optional <code>backenddomain</code> element allows specifying a
+          backend domain (aka driver domain) hosting the disk.  Use the
+          <code>name</code> attribute to specify the backend domain name.
+          <span class="since">Since 1.2.13 (Xen only)</span>
+      </dd>
       <dt><code>boot</code></dt>
       <dd>Specifies that the disk is bootable. The <code>order</code>
         attribute determines the order in which devices will be tried during
@@ -4256,6 +4262,29 @@ qemu-kvm -net nic,model=? /dev/null
       network device.
       <span class="since">Since 0.9.10 (QEMU and KVM only)</span>.
     </p>
+    <h5><a name="elementDomain">Setting up a network backend in a driver domain</a></h5>
+<pre>
+  ...
+  &lt;devices&gt;
+    ...
+    &lt;interface type='bridge'&gt;
+      &lt;source bridge='br0'/&gt;
+      <b>&lt;backenddomain name='netvm'/&gt;</b>
+    &lt;/interface&gt;
+    ...
+  &lt;/devices&gt;
+  ...</pre>
+
+    <p>
+      The optional <code>backenddomain</code> element allows specifying a
+      backend domain (aka driver domain) for the interface. Use the
+      <code>name</code> attribute to specify the backend domain name. You
+      can use it to create a direct network link between domains (so data
+      will not go through host system). Use with type 'ethernet' to create
+      plain network link, or with type 'bridge' to connect to a bridge inside
+      the backend domain.
+      <span class="since">Since 1.2.13 (Xen only)</span>
+    </p>
 
     <h5><a name="elementQoS">Quality of service</a></h5>
 

diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index 27a24b46baa60ef59cf26882eaee7974ea713628..f41ca43434cc7ceab7746a2560fef048bf06a570 100644 (file)
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -1173,6 +1173,14 @@
       <optional>
         <ref name="deviceBoot"/>
       </optional>
+      <optional>
+        <element name="backenddomain">
+          <attribute name="name">
+            <ref name="domainName"/>
+          </attribute>
+          <empty/>
+        </element>
+      </optional>
       <optional>
         <element name="readonly">
           <empty/>
@@ -2371,6 +2379,14 @@
           <empty/>
         </element>
       </optional>
+      <optional>
+        <element name="backenddomain">
+          <attribute name="name">
+            <ref name="domainName"/>
+          </attribute>
+          <empty/>
+        </element>
+      </optional>
       <optional>
         <element name="model">
           <attribute name="type">

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index b155a5a34cc2df3cd40d9091fd51e096d48765e7..d95dd3ebd54d8361524b492749cdfde81a3f3592 100644 (file)
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -1267,6 +1267,7 @@ virDomainDiskDefFree(virDomainDiskDefPtr def)
     VIR_FREE(def->wwn);
     VIR_FREE(def->vendor);
     VIR_FREE(def->product);
+    VIR_FREE(def->domain_name);
     virDomainDeviceInfoClear(&def->info);
 
     VIR_FREE(def);
@@ -1449,6 +1450,7 @@ void virDomainNetDefFree(virDomainNetDefPtr def)
     VIR_FREE(def->backend.vhost);
     VIR_FREE(def->virtPortProfile);
     VIR_FREE(def->script);
+    VIR_FREE(def->domain_name);
     VIR_FREE(def->ifname);
     VIR_FREE(def->ifname_guest);
     VIR_FREE(def->ifname_guest_actual);
@@ -5887,6 +5889,7 @@ virDomainDiskDefParseXML(virDomainXMLOptionPtr xmlopt,
     char *discard = NULL;
     char *mirrorFormat = NULL;
     char *mirrorType = NULL;
+    char *domain_name = NULL;
     int expected_secret_usage = -1;
     int auth_secret_usage = -1;
     int ret = 0;
@@ -5952,6 +5955,9 @@ virDomainDiskDefParseXML(virDomainXMLOptionPtr xmlopt,
                 if (target &&
                     STRPREFIX(target, "ioemu:"))
                     memmove(target, target+6, strlen(target)-5);
+            } else if (!domain_name &&
+                       xmlStrEqual(cur->name, BAD_CAST "backenddomain")) {
+                domain_name = virXMLPropString(cur, "name");
             } else if (xmlStrEqual(cur->name, BAD_CAST "geometry")) {
                 if (virXPathUInt("string(./geometry/@cyls)",
                                  ctxt, &def->geometry.cylinders) < 0) {
@@ -6676,6 +6682,8 @@ virDomainDiskDefParseXML(virDomainXMLOptionPtr xmlopt,
     driverName = NULL;
     def->src->encryption = encryption;
     encryption = NULL;
+    def->domain_name = domain_name;
+    domain_name = NULL;
     def->serial = serial;
     serial = NULL;
     def->wwn = wwn;
@@ -6738,6 +6746,7 @@ virDomainDiskDefParseXML(virDomainXMLOptionPtr xmlopt,
     VIR_FREE(product);
     VIR_FREE(mirrorType);
     VIR_FREE(mirrorFormat);
+    VIR_FREE(domain_name);
 
     ctxt->node = save_ctxt;
     return def;
@@ -7527,6 +7536,7 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
     char *mode = NULL;
     char *linkstate = NULL;
     char *addrtype = NULL;
+    char *domain_name = NULL;
     char *vhostuser_mode = NULL;
     char *vhostuser_path = NULL;
     char *vhostuser_type = NULL;
@@ -7666,6 +7676,9 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
             } else if (!script &&
                        xmlStrEqual(cur->name, BAD_CAST "script")) {
                 script = virXMLPropString(cur, "path");
+            } else if (!domain_name &&
+                       xmlStrEqual(cur->name, BAD_CAST "backenddomain")) {
+                domain_name = virXMLPropString(cur, "name");
             } else if (xmlStrEqual(cur->name, BAD_CAST "model")) {
                 model = virXMLPropString(cur, "type");
             } else if (xmlStrEqual(cur->name, BAD_CAST "driver")) {
@@ -7965,6 +7978,10 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
         def->script = script;
         script = NULL;
     }
+    if (domain_name != NULL) {
+        def->domain_name = domain_name;
+        domain_name = NULL;
+    }
     if (ifname != NULL) {
         def->ifname = ifname;
         ifname = NULL;
@@ -8234,6 +8251,7 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
     VIR_FREE(mode);
     VIR_FREE(linkstate);
     VIR_FREE(addrtype);
+    VIR_FREE(domain_name);
     VIR_FREE(trustGuestRxFilters);
     VIR_FREE(ips);
     VIR_FREE(vhost_path);
@@ -17162,6 +17180,8 @@ virDomainDiskDefFormat(virBufferPtr buf,
                                         def->src->backingStoreRaw, 1) < 0)
         return -1;
 
+    virBufferEscapeString(buf, "<backenddomain name='%s'/>\n", def->domain_name);
+
     virDomainDiskGeometryDefFormat(buf, def);
     virDomainDiskBlockIoDefFormat(buf, def);
 
@@ -18136,6 +18156,7 @@ virDomainNetDefFormat(virBufferPtr buf,
 
     virBufferEscapeString(buf, "<script path='%s'/>\n",
                           def->script);
+    virBufferEscapeString(buf, "<backenddomain name='%s'/>\n", def->domain_name);
     if (def->ifname &&
         !((flags & VIR_DOMAIN_DEF_FORMAT_INACTIVE) &&
           (STRPREFIX(def->ifname, VIR_NET_GENERATED_PREFIX)))) {

diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 86db2ab9df3c817e8b8a425e365b6fe71335192c..02ddd93a4d2234b826f65cbd2c605cfff3fdee98 100644 (file)
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -700,6 +700,7 @@ struct _virDomainDiskDef {
     int sgio; /* enum virDomainDeviceSGIO */
     int discard; /* enum virDomainDiskDiscard */
     unsigned int iothread; /* unused = 0, > 0 specific thread # */
+    char *domain_name; /* backend domain name */
 };
 
 
@@ -996,6 +997,7 @@ struct _virDomainNetDef {
         unsigned long sndbuf;
     } tune;
     char *script;
+    char *domain_name; /* backend domain name */
     char *ifname;
     char *ifname_guest;
     char *ifname_guest_actual;