[v2,2/4] domain: Make <address type='pci'/> request address allocation

diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index 58b8cb6..150938d 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -2930,7 +2930,10 @@ 
         (<span class="since">since 0.9.7, requires QEMU
         0.13</span>). <code>multifunction</code> defaults to 'off',
         but should be set to 'on' for function 0 of a slot that will
-        have multiple functions used.
+        have multiple functions used.<br/>
+        <span class="since">Since 1.3.5</span>, some hypervisor drivers
+        may accept a bare <code>&lt;address type='pci'/&gt;</code> XML block
+        as an explicit request to allocate a PCI address for the device.
       </dd>
       <dt><code>drive</code></dt>
       <dd>Drive addresses have the following additional
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index 8798001..94ffab2 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -4538,7 +4538,10 @@ 
           <attribute name="type">
             <value>pci</value>
           </attribute>
-          <ref name="pciaddress"/>
+          <choice>
+            <ref name="pciaddress"/>
+            <empty/>
+          </choice>
         </group>
         <group>
           <attribute name="type">
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 1c8d326..fd21dba 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -3924,6 +3924,23 @@  virDomainDefPostParseTimer(virDomainDefPtr def)
 }
 
 
+static int
+virDomainCheckUnallocatedDeviceAddrs(virDomainDefPtr def ATTRIBUTE_UNUSED,
+                                     virDomainDeviceDefPtr dev,
+                                     virDomainDeviceInfoPtr info,
+                                     void *data ATTRIBUTE_UNUSED)
+{
+    if (!info->auto_allocate)
+        return 0;
+
+    virReportError(VIR_ERR_INTERNAL_ERROR,
+        _("driver didn't allocate requested address type '%s' for device '%s'"),
+        virDomainDeviceAddressTypeToString(info->type),
+        virDomainDeviceTypeToString(dev->type));
+    return -1;
+}
+
+
 /* Check if a drive type address $controller:$bus:$target:$unit is already
  * taken by a disk or not.
  */
@@ -4455,6 +4472,12 @@  virDomainDefPostParse(virDomainDefPtr def,
             return ret;
     }
 
+    /* Ensure the driver filled in any auto_allocate addresses.
+       This must come after the assignAddressesCallback */
+    if (virDomainDeviceInfoIterate(def, virDomainCheckUnallocatedDeviceAddrs,
+                                   NULL) < 0)
+        return -1;
+
     if (virDomainDefPostParseCheckFeatures(def, xmlopt) < 0)
         return -1;
 
@@ -5091,8 +5114,13 @@  virDomainDeviceInfoParseXML(xmlNodePtr node,
 
     switch ((virDomainDeviceAddressType) info->type) {
     case VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI:
-        if (virPCIDeviceAddressParseXML(address, &info->addr.pci) < 0)
+        if (virXMLPropertyCount(address) == 1) {
+            /* Bare <address type='pci'/> is a request to allocate
+               the address. */
+            info->auto_allocate = true;
+        } else if (virPCIDeviceAddressParseXML(address, &info->addr.pci) < 0) {
             goto cleanup;
+        }
         break;
 
     case VIR_DOMAIN_DEVICE_ADDRESS_TYPE_DRIVE:
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 02594fe..d347e8f 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -347,6 +347,7 @@  struct _virDomainDeviceInfo {
      */
     char *alias;
     int type; /* virDomainDeviceAddressType */
+    bool auto_allocate;
     union {
         virPCIDeviceAddress pci;
         virDomainDeviceDriveAddress drive;
diff --git a/tests/genericxml2xmlindata/generic-pci-autofill-addr.xml b/tests/genericxml2xmlindata/generic-pci-autofill-addr.xml
new file mode 100644
index 0000000..06eadb6
--- /dev/null
+++ b/tests/genericxml2xmlindata/generic-pci-autofill-addr.xml
@@ -0,0 +1,27 @@ 
+<domain type='test'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='i686' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu</emulator>
+    <disk type='block' device='disk'>
+      <driver name='qemu' type='raw'/>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='vda' bus='virtio'/>
+      <address type='pci'/>
+    </disk>
+    <controller type='usb' index='0'>
+      <address type='pci'/>
+    </controller>
+  </devices>
+</domain>
diff --git a/tests/genericxml2xmltest.c b/tests/genericxml2xmltest.c
index 70ecd2d..2c492c3 100644
--- a/tests/genericxml2xmltest.c
+++ b/tests/genericxml2xmltest.c
@@ -91,6 +91,9 @@  mymain(void)
     DO_TEST_FULL("name-slash-parse", 0, false,
         TEST_COMPARE_DOM_XML2XML_RESULT_FAIL_PARSE);
 
+    DO_TEST_FULL("pci-autofill-addr", 0, false,
+        TEST_COMPARE_DOM_XML2XML_RESULT_FAIL_PARSE);
+
     virObjectUnref(caps);
     virObjectUnref(xmlopt);