conf: Add ioeventfd option for controllers

This will be used with a virtio-scsi controller later on.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>

docs/formatdomain.html.in

@@ -3000,6 +3000,14 @@
         a sector is 512 bytes.
         <span class="since">Since 1.2.7 (QEMU and KVM only)</span>
       </dd>
+      <dt><code>ioeventfd</code></dt>
+      <dd>
+        The optional <code>ioeventfd</code> attribute specifies
+        whether the controller should use
+        <a href='https://patchwork.kernel.org/patch/43390/'>
+        I/O asynchronous handling</a> or not.  Accepted values are
+        "on" and "off". <span class="since">Since 1.2.18</span>
+      </dd>
     </dl>
     <p>
       USB companion controllers have an optional

docs/schemas/domaincommon.rng

@@ -1832,6 +1832,9 @@
                 <ref name="unsignedInt"/>
               </attribute>
             </optional>
+            <optional>
+              <ref name="ioeventfd"/>
+            </optional>
           </element>
         </optional>
       </interleave>

src/conf/domain_conf.c

@@ -7824,6 +7824,7 @@ virDomainControllerDefParseXML(xmlNodePtr node,
     char *chassisNr = NULL;
     char *chassis = NULL;
     char *port = NULL;
+    char *ioeventfd = NULL;
     xmlNodePtr saved = ctxt->node;
     int rc;
 
@@ -7867,6 +7868,7 @@ virDomainControllerDefParseXML(xmlNodePtr node,
                 queues = virXMLPropString(cur, "queues");
                 cmd_per_lun = virXMLPropString(cur, "cmd_per_lun");
                 max_sectors = virXMLPropString(cur, "max_sectors");
+                ioeventfd = virXMLPropString(cur, "ioeventfd");
             } else if (xmlStrEqual(cur->name, BAD_CAST "model")) {
                 if (processedModel) {
                     virReportError(VIR_ERR_XML_ERROR, "%s",
@@ -7910,6 +7912,13 @@ virDomainControllerDefParseXML(xmlNodePtr node,
         goto error;
     }
 
+    if (ioeventfd &&
+        (def->ioeventfd = virTristateSwitchTypeFromString(ioeventfd)) < 0) {
+        virReportError(VIR_ERR_XML_ERROR,
+                       _("Malformed 'ioeventfd' value %s'"), max_sectors);
+        goto error;
+    }
+
     if (def->type == VIR_DOMAIN_CONTROLLER_TYPE_USB &&
         def->model == VIR_DOMAIN_CONTROLLER_MODEL_USB_NONE) {
         VIR_DEBUG("Ignoring device address for none model usb controller");
@@ -8083,6 +8092,7 @@ virDomainControllerDefParseXML(xmlNodePtr node,
     VIR_FREE(chassisNr);
     VIR_FREE(chassis);
     VIR_FREE(port);
+    VIR_FREE(ioeventfd);
 
     return def;
 
@@ -19148,7 +19158,7 @@ virDomainControllerDefFormat(virBufferPtr buf,
     }
 
     if (pciModel || pciTarget ||
-        def->queues || def->cmd_per_lun || def->max_sectors ||
+        def->queues || def->cmd_per_lun || def->max_sectors || def->ioeventfd ||
         virDomainDeviceInfoNeedsFormat(&def->info, flags) || pcihole64) {
         virBufferAddLit(buf, ">\n");
         virBufferAdjustIndent(buf, 2);
@@ -19178,7 +19188,8 @@ virDomainControllerDefFormat(virBufferPtr buf,
             virBufferAddLit(buf, "/>\n");
         }
 
-        if (def->queues || def->cmd_per_lun || def->max_sectors) {
+        if (def->queues || def->cmd_per_lun ||
+            def->max_sectors || def->ioeventfd) {
             virBufferAddLit(buf, "<driver");
             if (def->queues)
                 virBufferAsprintf(buf, " queues='%u'", def->queues);
@@ -19188,6 +19199,11 @@ virDomainControllerDefFormat(virBufferPtr buf,
 
             if (def->max_sectors)
                 virBufferAsprintf(buf, " max_sectors='%u'", def->max_sectors);
+
+            if (def->ioeventfd) {
+                virBufferAsprintf(buf, " ioeventfd='%s'",
+                                  virTristateSwitchTypeToString(def->ioeventfd));
+            }
             virBufferAddLit(buf, "/>\n");
         }
 

src/conf/domain_conf.h

@@ -840,6 +840,7 @@ struct _virDomainControllerDef {
     unsigned int queues;
     unsigned int cmd_per_lun;
     unsigned int max_sectors;
+    int ioeventfd; /* enum virTristateSwitch */
     union {
         virDomainVirtioSerialOpts vioserial;
         virDomainPCIControllerOpts pciopts;

tests/qemuxml2argvdata/qemuxml2argv-disk-virtio-scsi-ioeventfd.xml

@@ -0,0 +1,29 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>8</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'>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='sdb' bus='scsi'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <controller type='usb' index='0'/>
+    <controller type='scsi' index='0' model='virtio-scsi'>
+      <driver ioeventfd='on'/>
+    </controller>
+    <controller type='pci' index='0' model='pci-root'/>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>

tests/qemuxml2xmltest.c

@@ -420,6 +420,7 @@ mymain(void)
     DO_TEST("disk-virtio-scsi-num_queues");
     DO_TEST("disk-virtio-scsi-cmd_per_lun");
     DO_TEST("disk-virtio-scsi-max_sectors");
+    DO_TEST("disk-virtio-scsi-ioeventfd");
     DO_TEST("disk-scsi-megasas");
     DO_TEST_DIFFERENT("disk-mirror-old");
     DO_TEST_FULL("disk-mirror", false, WHEN_ACTIVE);