conf: Add support for blkiotune group_name option

Modify _virDomainBlockIoTuneInfo and rng schema to support the group_name
option for iotune throttling. Document the new value.

Signed-off-by: John Ferlan <jferlan@redhat.com>

docs/formatdomain.html.in

@@ -2622,6 +2622,17 @@
             <span class="since">Throughput limits since 1.2.11 and QEMU 1.7</span>
           </p>
           </dd>
+          <dt><code>group_name</code></dt>
+          <dd>The optional <code>group_name</code> provides the cability
+            to share I/O throttling quota between multiple drives. This
+            prevents end-users from circumventing a hosting provider's
+            throttling policy by splitting 1 large drive in N small drives
+            and getting N times the normal throttling quota. Any name may
+            be used.
+          <p>
+            <span class="since">group_name since 3.0.0 and QEMU 2.4</span>
+          </p>
+          </dd>
           <dt><code>total_bytes_sec_max_length</code></dt>
           <dd>The optional <code>total_bytes_sec_max_length</code>
             element is the maximum duration in seconds for the

docs/schemas/domaincommon.rng

@@ -4997,6 +4997,11 @@
             <data type="unsignedLong"/>
           </element>
         </optional>
+        <optional>
+          <element name="group_name">
+            <text/>
+          </element>
+        </optional>
         <choice>
           <element name="total_bytes_sec_max_length">
             <data type="unsignedLong"/>

src/conf/domain_conf.c

@@ -7401,6 +7401,9 @@ virDomainDiskDefIotuneParse(virDomainDiskDefPtr def,
     PARSE_IOTUNE(read_iops_sec_max_length);
     PARSE_IOTUNE(write_iops_sec_max_length);
 
+    def->blkdeviotune.group_name =
+        virXPathString("string(./iotune/group_name)", ctxt);
+
     if ((def->blkdeviotune.total_bytes_sec &&
          def->blkdeviotune.read_bytes_sec) ||
         (def->blkdeviotune.total_bytes_sec &&
@@ -20630,6 +20633,7 @@ virDomainDiskDefFormat(virBufferPtr buf,
         def->blkdeviotune.read_iops_sec_max ||
         def->blkdeviotune.write_iops_sec_max ||
         def->blkdeviotune.size_iops_sec ||
+        def->blkdeviotune.group_name ||
         def->blkdeviotune.total_bytes_sec_max_length ||
         def->blkdeviotune.read_bytes_sec_max_length ||
         def->blkdeviotune.write_bytes_sec_max_length ||
@@ -20658,6 +20662,11 @@ virDomainDiskDefFormat(virBufferPtr buf,
                               def->blkdeviotune.size_iops_sec);
         }
 
+        if (def->blkdeviotune.group_name) {
+            virBufferEscapeString(buf, "<group_name>%s</group_name>\n",
+                                  def->blkdeviotune.group_name);
+        }
+
         FORMAT_IOTUNE(total_bytes_sec_max_length);
         FORMAT_IOTUNE(read_bytes_sec_max_length);
         FORMAT_IOTUNE(write_bytes_sec_max_length);

tests/qemuxml2argvdata/qemuxml2argv-blkdeviotune-group-num.xml

@@ -0,0 +1,61 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219100</memory>
+  <currentMemory unit='KiB'>219100</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='qcow2' cache='none'/>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+      <iotune>
+        <total_bytes_sec>5000</total_bytes_sec>
+        <total_iops_sec>6000</total_iops_sec>
+        <total_bytes_sec_max>10000</total_bytes_sec_max>
+        <total_iops_sec_max>11000</total_iops_sec_max>
+        <group_name>libvirt_iotune_group1</group_name>
+      </iotune>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <disk type='block' device='disk'>
+      <driver name='qemu' type='qcow2' cache='none'/>
+      <source dev='/dev/HostVG/QEMUGuest2'/>
+      <target dev='hdb' bus='ide'/>
+      <iotune>
+        <read_bytes_sec>5000</read_bytes_sec>
+        <write_bytes_sec>5500</write_bytes_sec>
+        <read_iops_sec>3500</read_iops_sec>
+        <write_iops_sec>4000</write_iops_sec>
+        <read_bytes_sec_max>6000</read_bytes_sec_max>
+        <write_bytes_sec_max>6500</write_bytes_sec_max>
+        <read_iops_sec_max>7000</read_iops_sec_max>
+        <write_iops_sec_max>7500</write_iops_sec_max>
+        <size_iops_sec>2000</size_iops_sec>
+        <group_name>libvirt_iotune_group2</group_name>
+      </iotune>
+      <address type='drive' controller='0' bus='0' target='0' unit='1'/>
+    </disk>
+    <controller type='usb' index='0'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
+    </controller>
+    <controller type='ide' index='0'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
+    </controller>
+    <controller type='pci' index='0' model='pci-root'/>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <memballoon model='virtio'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
+    </memballoon>
+  </devices>
+</domain>

tests/qemuxml2xmloutdata/qemuxml2xmlout-blkdeviotune-group-num.xml

@@ -0,0 +1 @@
+../qemuxml2argvdata/qemuxml2argv-blkdeviotune-group-num.xml

tests/qemuxml2xmltest.c

@@ -611,6 +611,7 @@ mymain(void)
     DO_TEST("usb-redir-filter-version", NONE);
     DO_TEST("blkdeviotune", NONE);
     DO_TEST("blkdeviotune-max", NONE);
+    DO_TEST("blkdeviotune-group-num", NONE);
     DO_TEST("blkdeviotune-max-length", NONE);
     DO_TEST("controller-usb-order", NONE);