From 7e744f819921b871d20aa1bb2eccabd40c2a0f31 Mon Sep 17 00:00:00 2001
From: Michal Privoznik <mprivozn@redhat.com>
Date: Wed, 10 Apr 2013 12:19:37 +0200
Subject: [PATCH] Introduce /domain/devices/interface/driver/@queues attribute

This attribute is going to represent number of queues for
multique vhost network interface. This commit implements XML
extension part of the feature and add one test as well. For now,
we can only do xml2xml test as qemu command line generation code
is not adapted yet.
---
 docs/formatdomain.html.in                     | 12 ++++-
 docs/schemas/domaincommon.rng                 |  5 ++
 src/conf/domain_conf.c                        | 15 ++++++
 src/conf/domain_conf.h                        |  1 +
 .../qemuxml2argv-vhost_queues.xml             | 51 +++++++++++++++++++
 tests/qemuxml2xmltest.c                       |  1 +
 6 files changed, 84 insertions(+), 1 deletion(-)
 create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-vhost_queues.xml

diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index 8c12690753..3a200aa09e 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -3265,7 +3265,7 @@ qemu-kvm -net nic,model=? /dev/null
       &lt;source network='default'/&gt;
       &lt;target dev='vnet1'/&gt;
       &lt;model type='virtio'/&gt;
-      <b>&lt;driver name='vhost' txmode='iothread' ioeventfd='on' event_idx='off'/&gt;</b>
+      <b>&lt;driver name='vhost' txmode='iothread' ioeventfd='on' event_idx='off' queues='5'/&gt;</b>
     &lt;/interface&gt;
   &lt;/devices&gt;
   ...</pre>
@@ -3359,6 +3359,16 @@ qemu-kvm -net nic,model=? /dev/null
         <b>In general you should leave this option alone, unless you
         are very certain you know what you are doing.</b>
       </dd>
+      <dt><code>queues</code></dt>
+      <dd>
+        The optional <code>queues</code> attribute controls the number of
+        queues to be used for the<a href="http://www.linux-kvm.org/page/Multiqueue">
+        Multiqueue virtio-net</a> feature. If the interface has <code>&lt;model
+        type='virtio'/&gt;</code>, multiple packet processing queues can be
+        created; each queue will potentially be handled by a different
+        processor, resulting in much higher throughput.
+        <span class="since">Since 1.0.6 (QEMU and KVM only)</span>
+      </dd>
     </dl>
 
     <h5><a name="elementsNICSTargetOverride">Overriding the target element</a></h5>
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index 939654f4ea..3cace351a6 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -2012,6 +2012,11 @@
                   </choice>
                 </attribute>
               </optional>
+              <optional>
+                <attribute name='queues'>
+                  <ref name="positiveInteger"/>
+                </attribute>
+              </optional>
               <optional>
                 <attribute name="txmode">
                   <choice>
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 746f0d061c..ae9c0a4c3a 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -6001,6 +6001,7 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
     char *txmode = NULL;
     char *ioeventfd = NULL;
     char *event_idx = NULL;
+    char *queues = NULL;
     char *filter = NULL;
     char *internal = NULL;
     char *devaddr = NULL;
@@ -6112,6 +6113,7 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
                 txmode = virXMLPropString(cur, "txmode");
                 ioeventfd = virXMLPropString(cur, "ioeventfd");
                 event_idx = virXMLPropString(cur, "event_idx");
+                queues = virXMLPropString(cur, "queues");
             } else if (xmlStrEqual(cur->name, BAD_CAST "filterref")) {
                 if (filter) {
                     virReportError(VIR_ERR_XML_ERROR, "%s",
@@ -6402,6 +6404,16 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
             }
             def->driver.virtio.event_idx = idx;
         }
+        if (queues) {
+            unsigned int q;
+            if (virStrToLong_ui(queues, NULL, 10, &q) < 0) {
+                virReportError(VIR_ERR_XML_DETAIL,
+                               _("'queues' attribute must be positive number: %s"),
+                               queues);
+                goto error;
+            }
+            def->driver.virtio.queues = q;
+        }
     }
 
     def->linkstate = VIR_DOMAIN_NET_INTERFACE_LINK_STATE_DEFAULT;
@@ -6455,6 +6467,7 @@ cleanup:
     VIR_FREE(txmode);
     VIR_FREE(ioeventfd);
     VIR_FREE(event_idx);
+    VIR_FREE(queues);
     VIR_FREE(filter);
     VIR_FREE(type);
     VIR_FREE(internal);
@@ -14497,6 +14510,8 @@ virDomainNetDefFormat(virBufferPtr buf,
                 virBufferAsprintf(buf, " event_idx='%s'",
                                   virDomainVirtioEventIdxTypeToString(def->driver.virtio.event_idx));
             }
+            if (def->driver.virtio.queues)
+                virBufferAsprintf(buf, " queues='%u'", def->driver.virtio.queues);
             virBufferAddLit(buf, "/>\n");
         }
     }
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index f9f3994fbc..3a71d6c8f5 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -934,6 +934,7 @@ struct _virDomainNetDef {
             enum virDomainNetVirtioTxModeType txmode;
             enum virDomainIoEventFd ioeventfd;
             enum virDomainVirtioEventIdx event_idx;
+            unsigned int queues; /* Multiqueue virtio-net */
         } virtio;
     } driver;
     union {
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-vhost_queues.xml b/tests/qemuxml2argvdata/qemuxml2argv-vhost_queues.xml
new file mode 100644
index 0000000000..76f84f622c
--- /dev/null
+++ b/tests/qemuxml2argvdata/qemuxml2argv-vhost_queues.xml
@@ -0,0 +1,51 @@
+<domain type='qemu'>
+  <name>test</name>
+  <uuid>bba65c0e-c049-934f-b6aa-4e2c0582acdf</uuid>
+  <memory unit='KiB'>1048576</memory>
+  <currentMemory unit='KiB'>1048576</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc-0.13'>hvm</type>
+    <boot dev='cdrom'/>
+    <boot dev='hd'/>
+    <bootmenu enable='yes'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>restart</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu</emulator>
+    <disk type='file' device='disk'>
+      <driver name='qemu' type='qcow2' event_idx='on'/>
+      <source file='/var/lib/libvirt/images/f14.img'/>
+      <target dev='vda' bus='virtio'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
+    </disk>
+    <disk type='file' device='cdrom'>
+      <driver name='qemu' type='raw'/>
+      <source file='/var/lib/libvirt/Fedora-14-x86_64-Live-KDE.iso'/>
+      <target dev='hdc' bus='ide'/>
+      <readonly/>
+      <address type='drive' controller='0' bus='1' target='0' unit='0'/>
+    </disk>
+    <controller type='usb' index='0'/>
+    <controller type='virtio-serial' index='0'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
+    </controller>
+    <controller type='ide' index='0'/>
+    <controller type='pci' index='0' model='pci-root'/>
+    <interface type='user'>
+      <mac address='52:54:00:e5:48:58'/>
+      <model type='virtio'/>
+      <driver name='vhost' queues='5'/>
+    </interface>
+    <serial type='pty'>
+      <target port='0'/>
+    </serial>
+    <console type='pty'>
+      <target type='serial' port='0'/>
+    </console>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>
diff --git a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c
index fde6fa373c..64a271cb7a 100644
--- a/tests/qemuxml2xmltest.c
+++ b/tests/qemuxml2xmltest.c
@@ -246,6 +246,7 @@ mymain(void)
     DO_TEST("smp");
     DO_TEST("lease");
     DO_TEST("event_idx");
+    DO_TEST("vhost_queues");
     DO_TEST("virtio-lun");
 
     DO_TEST("usb-redir");