conf, docs: Add support for coalesce setting(s)

We are currently parsing only rx/frames/max because that's the only
value that makes sense for us.  The tun device just added support for
this one and the others are only supported by hardware devices which
we don't need to worry about as the only way we'd pass those to the
domain is using <hostdev/> or <interface type='hostdev'/>.  And in
those cases the guest can modify the settings itself.

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

docs/formatdomain.html.in

@@ -5405,6 +5405,33 @@ qemu-kvm -net nic,model=? /dev/null
       <span class="since">Since 3.1.0</span>
     </p>
 
+    <h5><a name="coalesce">Coalesce settings</a></h5>
+<pre>
+...
+&lt;devices&gt;
+  &lt;interface type='network'&gt;
+    &lt;source network='default'/&gt;
+    &lt;target dev='vnet0'/&gt;
+    <b>&lt;coalesce&gt;
+      &lt;rx&gt;
+        &lt;frames max='7'/&gt;
+      &lt;/rx&gt;
+    &lt;/coalesce&gt;</b>
+  &lt;/interface&gt;
+&lt;/devices&gt;
+...</pre>
+
+    <p>
+      This element provides means of setting coalesce settings for
+      some interface devices (currently only type <code>network</code>
+      and <code>bridge</code>.  Currently there is just one attribute,
+      <code>max</code>, to tweak, in element <code>frames<code> for
+      the <code>rx</code> group, which accepts a non-negative integer
+      that specifies the maximum number of packets that will be
+      received before an interrupt.
+      <span class="since">Since 3.3.0</span>
+    </p>
+
     <h5><a name="ipconfig">IP configuration</a></h5>
 <pre>
 ...

docs/schemas/domaincommon.rng

@@ -2508,6 +2508,9 @@
       <optional>
         <ref name="mtu"/>
       </optional>
+      <optional>
+        <ref name="coalesce"/>
+      </optional>
       <optional>
         <element name="target">
           <attribute name="dev">
@@ -5743,4 +5746,132 @@
       </choice>
     </attribute>
   </define>
+
+  <define name="coalesce">
+    <element name="coalesce">
+      <interleave>
+        <optional>
+          <element name="rx">
+            <optional>
+              <element name="frames">
+                <optional>
+                  <attribute name="max">
+                    <ref name="unsignedInt"/>
+                  </attribute>
+                </optional>
+                <!--
+                    This is how we'd add more Rx-related settings for
+                    frames, like irq, high, and low
+
+                <optional>
+                  <attribute name="irq">
+                    <ref name="unsignedInt"/>
+                  </attribute>
+                </optional>
+                <optional>
+                  <attribute name="high">
+                    <ref name="unsignedInt"/>
+                  </attribute>
+                </optional>
+                <optional>
+                  <attribute name="low">
+                    <ref name="unsignedInt"/>
+                  </attribute>
+                </optional>
+
+              -->
+              </element>
+            </optional>
+            <!--
+                This is how we'd add more Rx-related settings, like
+                usecs
+
+            <optional>
+              <element name="usecs">
+                <optional>
+                  <attribute name="max">
+                    <ref name="unsignedInt"/>
+                  </attribute>
+                </optional>
+                <optional>
+                  <attribute name="irq">
+                    <ref name="unsignedInt"/>
+                  </attribute>
+                </optional>
+                <optional>
+                  <attribute name="high">
+                    <ref name="unsignedInt"/>
+                  </attribute>
+                </optional>
+                <optional>
+                  <attribute name="low">
+                    <ref name="unsignedInt"/>
+                  </attribute>
+                </optional>
+              </element>
+            </optional>
+              -->
+          </element>
+        </optional>
+        <!--
+            This is how you would add more coalesce settings, like
+            Tx-related ones
+
+        <optional>
+          <element name="tx">
+            <optional>
+              <element name="frames">
+                <optional>
+                  <attribute name="max">
+                    <ref name="unsignedInt"/>
+                  </attribute>
+                </optional>
+                <optional>
+                  <attribute name="irq">
+                    <ref name="unsignedInt"/>
+                  </attribute>
+                </optional>
+                <optional>
+                  <attribute name="high">
+                    <ref name="unsignedInt"/>
+                  </attribute>
+                </optional>
+                <optional>
+                  <attribute name="low">
+                    <ref name="unsignedInt"/>
+                  </attribute>
+                </optional>
+              </element>
+            </optional>
+            <optional>
+              <element name="usecs">
+                <optional>
+                  <attribute name="max">
+                    <ref name="unsignedInt"/>
+                  </attribute>
+                </optional>
+                <optional>
+                  <attribute name="irq">
+                    <ref name="unsignedInt"/>
+                  </attribute>
+                </optional>
+                <optional>
+                  <attribute name="high">
+                    <ref name="unsignedInt"/>
+                  </attribute>
+                </optional>
+                <optional>
+                  <attribute name="low">
+                    <ref name="unsignedInt"/>
+                  </attribute>
+                </optional>
+              </element>
+            </optional>
+          </element>
+        </optional>
+        -->
+      </interleave>
+    </element>
+  </define>
+
 </grammar>

src/conf/domain_conf.c

@@ -6772,6 +6772,77 @@ virDomainNetIPInfoParseXML(const char *source,
     return ret;
 }
 
+
+static virNetDevCoalescePtr
+virDomainNetDefCoalesceParseXML(xmlNodePtr node,
+                                xmlXPathContextPtr ctxt)
+{
+    virNetDevCoalescePtr ret = NULL;
+    xmlNodePtr save = NULL;
+    char *str = NULL;
+    unsigned long long tmp = 0;
+
+    save = ctxt->node;
+    ctxt->node = node;
+
+    str = virXPathString("string(./rx/frames/@max)", ctxt);
+    if (!str)
+        goto cleanup;
+
+    if (!ret && VIR_ALLOC(ret) < 0)
+        goto cleanup;
+
+    if (virStrToLong_ullp(str, NULL, 10, &tmp) < 0) {
+        virReportError(VIR_ERR_XML_DETAIL,
+                       _("cannot parse value '%s' for coalesce parameter"),
+                       str);
+        VIR_FREE(str);
+        goto error;
+    }
+    VIR_FREE(str);
+
+    if (tmp > UINT32_MAX) {
+        virReportError(VIR_ERR_OVERFLOW,
+                       _("value '%llu' is too big for coalesce "
+                         "parameter, maximum is '%lu'"),
+                       tmp, (unsigned long) UINT32_MAX);
+        goto error;
+    }
+    ret->rx_max_coalesced_frames = tmp;
+
+ cleanup:
+    ctxt->node = save;
+    return ret;
+
+ error:
+    VIR_FREE(ret);
+    goto cleanup;
+}
+
+static void
+virDomainNetDefCoalesceFormatXML(virBufferPtr buf,
+                                 virNetDevCoalescePtr coalesce)
+{
+    if (!coalesce || !coalesce->rx_max_coalesced_frames)
+        return;
+
+    virBufferAddLit(buf, "<coalesce>\n");
+    virBufferAdjustIndent(buf, 2);
+
+    virBufferAddLit(buf, "<rx>\n");
+    virBufferAdjustIndent(buf, 2);
+
+    virBufferAsprintf(buf, "<frames max='%u'/>\n",
+                      coalesce->rx_max_coalesced_frames);
+
+    virBufferAdjustIndent(buf, -2);
+    virBufferAddLit(buf, "</rx>\n");
+
+    virBufferAdjustIndent(buf, -2);
+    virBufferAddLit(buf, "</coalesce>\n");
+}
+
+
 static int
 virDomainHostdevDefParseXMLCaps(xmlNodePtr node ATTRIBUTE_UNUSED,
                                 xmlXPathContextPtr ctxt,
@@ -10255,6 +10326,13 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
         goto error;
     }
 
+    node = virXPathNode("./coalesce", ctxt);
+    if (node) {
+        def->coalesce = virDomainNetDefCoalesceParseXML(node, ctxt);
+        if (!def->coalesce)
+            goto error;
+    }
+
  cleanup:
     ctxt->node = oldnode;
     VIR_FREE(macaddr);
@@ -22147,6 +22225,8 @@ virDomainNetDefFormat(virBufferPtr buf,
     if (def->mtu)
         virBufferAsprintf(buf, "<mtu size='%u'/>\n", def->mtu);
 
+    virDomainNetDefCoalesceFormatXML(buf, def->coalesce);
+
     if (virDomainDeviceInfoFormat(buf, &def->info,
                                   flags | VIR_DOMAIN_DEF_FORMAT_ALLOW_BOOT
                                   | VIR_DOMAIN_DEF_FORMAT_ALLOW_ROM) < 0)

src/conf/domain_conf.h

@@ -41,6 +41,7 @@
 # include "numa_conf.h"
 # include "virnetdevmacvlan.h"
 # include "virsysinfo.h"
+# include "virnetdev.h"
 # include "virnetdevip.h"
 # include "virnetdevvportprofile.h"
 # include "virnetdevbandwidth.h"
@@ -1036,6 +1037,7 @@ struct _virDomainNetDef {
     int trustGuestRxFilters; /* enum virTristateBool */
     int linkstate;
     unsigned int mtu;
+    virNetDevCoalescePtr coalesce;
 };
 
 /* Used for prefix of ifname of any network name generated dynamically

src/qemu/qemu_domain.c

@@ -2984,6 +2984,30 @@ qemuDomainDefValidate(const virDomainDef *def,
 }
 
 
+static bool
+qemuDomainNetSupportsCoalesce(virDomainNetType type)
+{
+    switch (type) {
+    case VIR_DOMAIN_NET_TYPE_NETWORK:
+    case VIR_DOMAIN_NET_TYPE_BRIDGE:
+        return true;
+    case VIR_DOMAIN_NET_TYPE_VHOSTUSER:
+    case VIR_DOMAIN_NET_TYPE_ETHERNET:
+    case VIR_DOMAIN_NET_TYPE_DIRECT:
+    case VIR_DOMAIN_NET_TYPE_HOSTDEV:
+    case VIR_DOMAIN_NET_TYPE_USER:
+    case VIR_DOMAIN_NET_TYPE_SERVER:
+    case VIR_DOMAIN_NET_TYPE_CLIENT:
+    case VIR_DOMAIN_NET_TYPE_MCAST:
+    case VIR_DOMAIN_NET_TYPE_INTERNAL:
+    case VIR_DOMAIN_NET_TYPE_UDP:
+    case VIR_DOMAIN_NET_TYPE_LAST:
+        break;
+    }
+    return false;
+}
+
+
 static int
 qemuDomainDeviceDefValidate(const virDomainDeviceDef *dev,
                             const virDomainDef *def ATTRIBUTE_UNUSED,
@@ -3018,6 +3042,13 @@ qemuDomainDeviceDefValidate(const virDomainDeviceDef *dev,
                            virDomainNetTypeToString(net->type));
             goto cleanup;
         }
+
+        if (net->coalesce && !qemuDomainNetSupportsCoalesce(net->type)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                           _("coalesce settings on interface type %s are not supported"),
+                           virDomainNetTypeToString(net->type));
+            goto cleanup;
+        }
     }
 
     ret = 0;

tests/qemuxml2argvdata/qemuxml2argv-net-coalesce.xml

@@ -0,0 +1,68 @@
+<domain type='qemu'>
+  <name>test</name>
+  <uuid>15d091de-0181-456b-9554-e4382dc1f1ab</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-system-x86_64</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='network'>
+      <source network='default'/>
+      <mac address='52:54:00:e5:48:58'/>
+      <model type='virtio'/>
+      <coalesce>
+        <rx>
+          <frames max='7'/>
+        </rx>
+      </coalesce>
+    </interface>
+    <interface type='network'>
+      <source network='default'/>
+      <mac address='52:54:00:e5:48:59'/>
+      <model type='virtio'/>
+      <coalesce>
+        <rx>
+          <frames max='0'/>
+        </rx>
+      </coalesce>
+    </interface>
+    <serial type='pty'>
+      <target port='0'/>
+    </serial>
+    <console type='pty'>
+      <target type='serial' port='0'/>
+    </console>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>

tests/qemuxml2xmloutdata/qemuxml2xmlout-net-coalesce.xml

@@ -0,0 +1,71 @@
+<domain type='qemu'>
+  <name>test</name>
+  <uuid>15d091de-0181-456b-9554-e4382dc1f1ab</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-system-x86_64</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'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
+    </controller>
+    <controller type='virtio-serial' index='0'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
+    </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'/>
+    <interface type='network'>
+      <mac address='52:54:00:e5:48:58'/>
+      <source network='default'/>
+      <model type='virtio'/>
+      <coalesce>
+        <rx>
+          <frames max='7'/>
+        </rx>
+      </coalesce>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
+    </interface>
+    <interface type='network'>
+      <mac address='52:54:00:e5:48:59'/>
+      <source network='default'/>
+      <model type='virtio'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
+    </interface>
+    <serial type='pty'>
+      <target port='0'/>
+    </serial>
+    <console type='pty'>
+      <target type='serial' port='0'/>
+    </console>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <memballoon model='virtio'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
+    </memballoon>
+  </devices>
+</domain>

tests/qemuxml2xmltest.c

@@ -528,6 +528,7 @@ mymain(void)
     DO_TEST("net-bandwidth", NONE);
     DO_TEST("net-bandwidth2", NONE);
     DO_TEST("net-mtu", NONE);
+    DO_TEST("net-coalesce", NONE);
 
     DO_TEST("serial-vc", NONE);
     DO_TEST("serial-pty", NONE);