diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index ba2586e516..31c132b94e 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -1883,6 +1883,13 @@
       <target dir='/import/from/host'/>
       <readonly/>
     </filesystem>
+    <filesystem type='file' accessmode='passthrough'>
+      <driver name='loop' type='raw'/>
+      <driver type='path' wrpolicy='immediate'/>
+      <source file='/export/to/guest.img'/>
+      <target dir='/import/from/host'/>
+      <readonly/>
+    </filesystem>
     ...
   </devices>
   ...</pre>
@@ -1974,6 +1981,23 @@
 
       </dd>
 
+      <dt><code>driver</code></dt>
+      <dd>
+        The optional driver element allows specifying further details
+        related to the hypervisor driver used to provide the filesystem.
+        <span class="since">Since 1.0.6</span>
+        <ul>
+          <li>
+            If the hypervisor supports multiple backend drivers, then
+            the <code>type</code> attribute selects the primary
+            backend driver name, while the <code>format</code>
+            attribute provides the format type. For example, LXC
+            supports a type of "loop", with a format of "raw". QEMU
+            supports a type of "path" or "handle", but no formats.
+          </li>
+        </ul>
+      </dd>
+
       <dt><code>source</code></dt>
       <dd>
         The resource on the host that is being accessed in the guest. The
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index 4fdacab5c4..6078b7a758 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -888,7 +888,7 @@
   <define name="diskspec">
     <interleave>
       <optional>
-        <ref name="driver"/>
+        <ref name="diskDriver"/>
       </optional>
       <optional>
         <ref name='diskMirror'/>
@@ -1270,7 +1270,7 @@
   <!--
       Disk may use a special driver for access.
     -->
-  <define name="driver">
+  <define name="diskDriver">
     <element name="driver">
       <choice>
         <group>
@@ -1314,13 +1314,13 @@
     <optional>
       <attribute name='type'>
         <choice>
-          <ref name='diskFormat'/>
+          <ref name='storageFormat'/>
           <value>aio</value> <!-- back-compat for 'raw' -->
         </choice>
       </attribute>
     </optional>
   </define>
-  <define name='diskFormat'>
+  <define name='storageFormat'>
     <choice>
       <value>raw</value>
       <value>dir</value>
@@ -1518,6 +1518,9 @@
           <attribute name="type">
             <value>file</value>
           </attribute>
+          <optional>
+            <ref name="fsDriver"/>
+          </optional>
           <interleave>
             <element name="source">
               <attribute name="file">
@@ -1531,6 +1534,9 @@
           <attribute name="type">
             <value>block</value>
           </attribute>
+          <optional>
+            <ref name="fsDriver"/>
+          </optional>
           <interleave>
             <element name="source">
               <attribute name="dev">
@@ -1547,6 +1553,9 @@
               <value>mount</value>
             </attribute>
           </optional>
+          <optional>
+            <ref name="fsDriver"/>
+          </optional>
           <interleave>
             <element name="source">
               <attribute name="dir">
@@ -1554,22 +1563,6 @@
               </attribute>
               <empty/>
             </element>
-            <optional>
-              <element name="driver">
-                <attribute name="type">
-                  <choice>
-                    <value>path</value>
-                    <value>handle</value>
-                  </choice>
-                </attribute>
-                <optional>
-                  <attribute name="wrpolicy">
-                    <value>immediate</value>
-                  </attribute>
-                </optional>
-                <empty/>
-              </element>
-            </optional>
           </interleave>
         </group>
         <group>
@@ -1578,6 +1571,9 @@
               <value>bind</value>
             </attribute>
           </optional>
+          <optional>
+            <ref name="fsDriver"/>
+          </optional>
           <interleave>
             <element name="source">
               <attribute name="dir">
@@ -1591,6 +1587,9 @@
           <attribute name="type">
             <value>template</value>
           </attribute>
+          <optional>
+            <ref name="fsDriver"/>
+          </optional>
           <interleave>
             <element name="source">
               <attribute name="name">
@@ -1604,6 +1603,9 @@
           <attribute name="type">
             <value>ram</value>
           </attribute>
+          <optional>
+            <ref name="fsDriver"/>
+          </optional>
           <interleave>
             <element name="source">
               <attribute name="usage">
@@ -1661,6 +1663,35 @@
       </interleave>
     </element>
   </define>
+  <define name="fsDriver">
+    <element name="driver">
+      <!-- Annoying inconsistency. 'disk' uses 'name'
+           for this kind of info, and 'type' for the
+           storage format. We need the latter too, so
+           had to invent a new attribute name -->
+      <optional>
+        <attribute name="type">
+          <choice>
+            <value>path</value>
+            <value>handle</value>
+            <value>loop</value>
+          </choice>
+        </attribute>
+      </optional>
+      <optional>
+        <attribute name="format">
+          <ref name="storageFormat"/>
+        </attribute>
+      </optional>
+      <optional>
+        <attribute name="wrpolicy">
+          <value>immediate</value>
+        </attribute>
+      </optional>
+      <empty/>
+    </element>
+  </define>
+
   <!--
       An interface description can either be of type bridge in which case
       it will use a bridging source, or of type ethernet which uses a device
@@ -3838,7 +3869,7 @@
       </attribute>
       <optional>
         <attribute name='format'>
-          <ref name='diskFormat'/>
+          <ref name='storageFormat'/>
         </attribute>
       </optional>
       <optional>
diff --git a/docs/schemas/domainsnapshot.rng b/docs/schemas/domainsnapshot.rng
index 45d55b56c5..7b46df1c1b 100644
--- a/docs/schemas/domainsnapshot.rng
+++ b/docs/schemas/domainsnapshot.rng
@@ -128,7 +128,7 @@
               <element name='driver'>
                 <optional>
                   <attribute name='type'>
-                    <ref name='diskFormat'/>
+                    <ref name='storageFormat'/>
                   </attribute>
                 </optional>
                 <empty/>
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 209602777d..ddf9ace16e 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -342,7 +342,8 @@ VIR_ENUM_IMPL(virDomainFS, VIR_DOMAIN_FS_TYPE_LAST,
 VIR_ENUM_IMPL(virDomainFSDriverType, VIR_DOMAIN_FS_DRIVER_TYPE_LAST,
               "default",
               "path",
-              "handle")
+              "handle",
+              "loop")
 
 VIR_ENUM_IMPL(virDomainFSAccessMode, VIR_DOMAIN_FS_ACCESSMODE_LAST,
               "passthrough",
@@ -5596,6 +5597,7 @@ virDomainFSDefParseXML(xmlNodePtr node,
     char *fsdriver = NULL;
     char *source = NULL;
     char *target = NULL;
+    char *format = NULL;
     char *accessmode = NULL;
     char *wrpolicy = NULL;
     char *usage = NULL;
@@ -5664,9 +5666,13 @@ virDomainFSDefParseXML(xmlNodePtr node,
                 target = virXMLPropString(cur, "dir");
             } else if (xmlStrEqual(cur->name, BAD_CAST "readonly")) {
                 def->readonly = true;
-            } else if (!fsdriver && xmlStrEqual(cur->name, BAD_CAST "driver")) {
-                fsdriver = virXMLPropString(cur, "type");
-                wrpolicy = virXMLPropString(cur, "wrpolicy");
+            } else if (xmlStrEqual(cur->name, BAD_CAST "driver")) {
+                if (!fsdriver)
+                    fsdriver = virXMLPropString(cur, "type");
+                if (!wrpolicy)
+                    wrpolicy = virXMLPropString(cur, "wrpolicy");
+                if (!format)
+                    format = virXMLPropString(cur, "format");
             }
         }
         cur = cur->next;
@@ -5674,12 +5680,20 @@ virDomainFSDefParseXML(xmlNodePtr node,
 
     if (fsdriver) {
         if ((def->fsdriver = virDomainFSDriverTypeTypeFromString(fsdriver)) <= 0) {
-            virReportError(VIR_ERR_INTERNAL_ERROR,
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                            _("unknown fs driver type '%s'"), fsdriver);
             goto error;
         }
     }
 
+    if (format) {
+        if ((def->format = virStorageFileFormatTypeFromString(format)) <= 0) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                           _("unknown driver format value '%s'"), format);
+            goto error;
+        }
+    }
+
     if (wrpolicy) {
         if ((def->wrpolicy = virDomainFSWrpolicyTypeFromString(wrpolicy)) <= 0) {
             virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
@@ -5739,6 +5753,7 @@ cleanup:
     VIR_FREE(wrpolicy);
     VIR_FREE(usage);
     VIR_FREE(unit);
+    VIR_FREE(format);
 
     return def;
 
@@ -13947,10 +13962,13 @@ virDomainFSDefFormat(virBufferPtr buf,
     if (def->fsdriver) {
         virBufferAsprintf(buf, "      <driver type='%s'", fsdriver);
 
+        if (def->format)
+            virBufferAsprintf(buf, " format='%s'",
+                              virStorageFileFormatTypeToString(def->format));
+
         /* Don't generate anything if wrpolicy is set to default */
-        if (def->wrpolicy) {
+        if (def->wrpolicy)
             virBufferAsprintf(buf, " wrpolicy='%s'", wrpolicy);
-        }
 
         virBufferAddLit(buf, "/>\n");
     }
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 5471cd3906..b5a0db83d2 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -800,6 +800,7 @@ enum virDomainFSDriverType {
     VIR_DOMAIN_FS_DRIVER_TYPE_DEFAULT = 0,
     VIR_DOMAIN_FS_DRIVER_TYPE_PATH,
     VIR_DOMAIN_FS_DRIVER_TYPE_HANDLE,
+    VIR_DOMAIN_FS_DRIVER_TYPE_LOOP,
 
     VIR_DOMAIN_FS_DRIVER_TYPE_LAST
 };
@@ -826,9 +827,10 @@ enum virDomainFSWrpolicy {
 
 struct _virDomainFSDef {
     int type;
-    int fsdriver;
-    int accessmode;
+    int fsdriver; /* enum virDomainFSDriverType */
+    int accessmode; /* enum virDomainFSAccessMode */
     int wrpolicy; /* enum virDomainFSWrpolicy */
+    int format; /* enum virStorageFileFormat */
     unsigned long long usage;
     char *src;
     char *dst;
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 178107d757..372e1a3215 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -139,7 +139,8 @@ VIR_ENUM_DECL(qemuDomainFSDriver)
 VIR_ENUM_IMPL(qemuDomainFSDriver, VIR_DOMAIN_FS_DRIVER_TYPE_LAST,
               "local",
               "local",
-              "handle");
+              "handle",
+              NULL);
 
 
 /**
diff --git a/tests/lxcxml2xmldata/lxc-disk-formats.xml b/tests/lxcxml2xmldata/lxc-disk-formats.xml
new file mode 100644
index 0000000000..da53cf22b0
--- /dev/null
+++ b/tests/lxcxml2xmldata/lxc-disk-formats.xml
@@ -0,0 +1,26 @@
+<domain type='lxc'>
+  <name>demo</name>
+  <uuid>8369f1ac-7e46-e869-4ca5-759d51478066</uuid>
+  <memory unit='KiB'>500000</memory>
+  <currentMemory unit='KiB'>500000</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64'>exe</type>
+    <init>/bin/sh</init>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/libexec/libvirt_lxc</emulator>
+    <filesystem type='file' accessmode='passthrough'>
+      <driver type='loop' format='raw'/>
+      <source file='/root/container.img'/>
+      <target dir='/'/>
+    </filesystem>
+    <console type='pty'>
+      <target type='lxc' port='0'/>
+    </console>
+  </devices>
+</domain>
diff --git a/tests/lxcxml2xmltest.c b/tests/lxcxml2xmltest.c
index 827c2fd267..97f792c25e 100644
--- a/tests/lxcxml2xmltest.c
+++ b/tests/lxcxml2xmltest.c
@@ -128,6 +128,7 @@ mymain(void)
 
     DO_TEST("systemd");
     DO_TEST("hostdev");
+    DO_TEST("disk-formats");
 
     virObjectUnref(caps);
     virObjectUnref(xmlopt);