conf: Add support for memorytune XML processing for resctrl MBA

Introduce a new section memorytune to support memory bandwidth allocation.
This is consistent with existing cachetune. As the example:
below:
  <cputune>
    ......
    <memorytune vcpus='0'>
      <node id='0' bandwidth='30'/>
    </memorytune>
  </cputune>

vpus      --- vpus subjected to this memory bandwidth.
id        --- on which node memory bandwidth to be set.
bandwidth --- the memory bandwidth percent to set.

Signed-off-by: Bing Niu <bing.niu@intel.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>

docs/formatdomain.html.in

@@ -759,6 +759,10 @@
       <cache id='0' level='3' type='both' size='3' unit='MiB'/>
       <cache id='1' level='3' type='both' size='3' unit='MiB'/>
     </cachetune>
+    <memorytune vcpus='0-3'>
+      <node id='0' bandwidth='60'/>
+    </memorytune>
+
   </cputune>
   ...
 </domain>
@@ -932,7 +936,9 @@
         size and required granularity are reported as well. The required
         attribute <code>vcpus</code> specifies to which vCPUs this allocation
         applies. A vCPU can only be member of one <code>cachetune</code> element
-        allocations. Supported subelements are:
+        allocation. The vCPUs specified by cachetune can be identical with those
+        in memorytune, however they are not allowed to overlap.
+        Supported subelements are:
         <dl>
           <dt><code>cache</code></dt>
           <dd>
@@ -972,7 +978,38 @@
             </dl>
           </dd>
         </dl>
+      </dd>
 
+      <dt><code>memorytune</code><span class="since">Since 4.7.0</span></dt>
+      <dd>
+        Optional <code>memorytune</code> element can control allocations for
+        memory bandwidth using the resctrl on the host. Whether or not is this
+        supported can be gathered from capabilities where some limitations like
+        minimum bandwidth and required granularity are reported as well. The
+        required attribute <code>vcpus</code> specifies to which vCPUs this
+        allocation applies. A vCPU can only be member of one
+        <code>memorytune</code> element allocation. The <code>vcpus</code> specified
+        by <code>memorytune</code> can be identical to those specified by
+        <code>cachetune</code>. However they are not allowed to overlap each other.
+        Supported subelements are:
+        <dl>
+          <dt><code>node</code></dt>
+          <dd>
+            This element controls the allocation of CPU memory bandwidth and has the
+            following attributes:
+            <dl>
+              <dt><code>id</code></dt>
+              <dd>
+                Host node id from which to allocate memory bandwidth.
+              </dd>
+              <dt><code>bandwidth</code></dt>
+              <dd>
+                The memory bandwidth to allocate from this node. The value by default
+                is in percentage.
+              </dd>
+            </dl>
+          </dd>
+        </dl>
       </dd>
     </dl>
 

docs/schemas/domaincommon.rng

@@ -983,6 +983,23 @@
             </oneOrMore>
           </element>
         </zeroOrMore>
+        <zeroOrMore>
+          <element name="memorytune">
+            <attribute name="vcpus">
+              <ref name='cpuset'/>
+            </attribute>
+            <oneOrMore>
+              <element name="node">
+                <attribute name="id">
+                  <ref name='unsignedInt'/>
+                </attribute>
+                <attribute name="bandwidth">
+                  <ref name='unsignedInt'/>
+                </attribute>
+              </element>
+            </oneOrMore>
+          </element>
+        </zeroOrMore>
       </interleave>
     </element>
   </define>

src/conf/domain_conf.c

@@ -19418,6 +19418,129 @@ virDomainDefParseCaps(virDomainDefPtr def,
 }
 
 
+static int
+virDomainMemorytuneDefParseMemory(xmlXPathContextPtr ctxt,
+                                  xmlNodePtr node,
+                                  virResctrlAllocPtr alloc)
+{
+    xmlNodePtr oldnode = ctxt->node;
+    unsigned int id;
+    unsigned int bandwidth;
+    char *tmp = NULL;
+    int ret = -1;
+
+    ctxt->node = node;
+
+    tmp = virXMLPropString(node, "id");
+    if (!tmp) {
+        virReportError(VIR_ERR_XML_ERROR, "%s",
+                       _("Missing memorytune attribute 'id'"));
+        goto cleanup;
+    }
+    if (virStrToLong_uip(tmp, NULL, 10, &id) < 0) {
+        virReportError(VIR_ERR_XML_ERROR,
+                       _("Invalid memorytune attribute 'id' value '%s'"),
+                       tmp);
+        goto cleanup;
+    }
+    VIR_FREE(tmp);
+
+    tmp = virXMLPropString(node, "bandwidth");
+    if (!tmp) {
+        virReportError(VIR_ERR_XML_ERROR, "%s",
+                       _("Missing memorytune attribute 'bandwidth'"));
+        goto cleanup;
+    }
+    if (virStrToLong_uip(tmp, NULL, 10, &bandwidth) < 0) {
+        virReportError(VIR_ERR_XML_ERROR,
+                       _("Invalid memorytune attribute 'bandwidth' value '%s'"),
+                       tmp);
+        goto cleanup;
+    }
+    VIR_FREE(tmp);
+    if (virResctrlAllocSetMemoryBandwidth(alloc, id, bandwidth) < 0)
+        goto cleanup;
+
+    ret = 0;
+ cleanup:
+    ctxt->node = oldnode;
+    VIR_FREE(tmp);
+    return ret;
+}
+
+
+static int
+virDomainMemorytuneDefParse(virDomainDefPtr def,
+                            xmlXPathContextPtr ctxt,
+                            xmlNodePtr node,
+                            unsigned int flags)
+{
+    xmlNodePtr oldnode = ctxt->node;
+    xmlNodePtr *nodes = NULL;
+    virBitmapPtr vcpus = NULL;
+    virResctrlAllocPtr alloc = NULL;
+    ssize_t i = 0;
+    int n;
+    int ret = -1;
+    bool new_alloc = false;
+
+    ctxt->node = node;
+
+    if (virDomainResctrlParseVcpus(def, node, &vcpus) < 0)
+        goto cleanup;
+
+    if (virBitmapIsAllClear(vcpus)) {
+        ret = 0;
+        goto cleanup;
+    }
+
+    if ((n = virXPathNodeSet("./node", ctxt, &nodes)) < 0) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("Cannot extract memory nodes under memorytune"));
+        goto cleanup;
+    }
+
+    if (virDomainResctrlVcpuMatch(def, vcpus, &alloc) < 0)
+        goto cleanup;
+
+    if (!alloc) {
+        alloc = virResctrlAllocNew();
+        if (!alloc)
+            goto cleanup;
+        new_alloc = true;
+    } else {
+        alloc = virObjectRef(alloc);
+    }
+
+    for (i = 0; i < n; i++) {
+        if (virDomainMemorytuneDefParseMemory(ctxt, nodes[i], alloc) < 0)
+            goto cleanup;
+    }
+    if (virResctrlAllocIsEmpty(alloc)) {
+        ret = 0;
+        goto cleanup;
+    }
+    /*
+     * If this is a new allocation, format ID and append to resctrl, otherwise
+     * just update the existing alloc information, which is done in above
+     * virDomainMemorytuneDefParseMemory */
+    if (new_alloc) {
+        if (virDomainResctrlAppend(def, node, alloc, vcpus, flags) < 0)
+            goto cleanup;
+        vcpus = NULL;
+        alloc = NULL;
+    }
+
+    ret = 0;
+ cleanup:
+    ctxt->node = oldnode;
+    virObjectUnref(alloc);
+    virBitmapFree(vcpus);
+    VIR_FREE(nodes);
+    return ret;
+}
+
+
 static virDomainDefPtr
 virDomainDefParseXML(xmlDocPtr xml,
                      xmlNodePtr root,
@@ -19897,6 +20020,18 @@ virDomainDefParseXML(xmlDocPtr xml,
     }
     VIR_FREE(nodes);
 
+    if ((n = virXPathNodeSet("./cputune/memorytune", ctxt, &nodes)) < 0) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("cannot extract memorytune nodes"));
+        goto error;
+    }
+
+    for (i = 0; i < n; i++) {
+        if (virDomainMemorytuneDefParse(def, ctxt, nodes[i], flags) < 0)
+            goto error;
+    }
+    VIR_FREE(nodes);
+
     if (virCPUDefParseXML(ctxt, "./cpu[1]", VIR_CPU_TYPE_GUEST, &def->cpu) < 0)
         goto error;
 
@@ -27198,6 +27333,68 @@ virDomainCachetuneDefFormat(virBufferPtr buf,
 }
 
 
+static int
+virDomainMemorytuneDefFormatHelper(unsigned int id,
+                                   unsigned int bandwidth,
+                                   void *opaque)
+{
+    virBufferPtr buf = opaque;
+
+    virBufferAsprintf(buf,
+                      "<node id='%u' bandwidth='%u'/>\n",
+                      id, bandwidth);
+    return 0;
+}
+
+
+static int
+virDomainMemorytuneDefFormat(virBufferPtr buf,
+                            virDomainResctrlDefPtr resctrl,
+                            unsigned int flags)
+{
+    virBuffer childrenBuf = VIR_BUFFER_INITIALIZER;
+    char *vcpus = NULL;
+    int ret = -1;
+
+    virBufferSetChildIndent(&childrenBuf, buf);
+    if (virResctrlAllocForeachMemory(resctrl->alloc,
+                                     virDomainMemorytuneDefFormatHelper,
+                                     &childrenBuf) < 0)
+        goto cleanup;
+
+    if (virBufferCheckError(&childrenBuf) < 0)
+        goto cleanup;
+
+    if (!virBufferUse(&childrenBuf)) {
+        ret = 0;
+        goto cleanup;
+    }
+
+    vcpus = virBitmapFormat(resctrl->vcpus);
+    if (!vcpus)
+        goto cleanup;
+
+    virBufferAsprintf(buf, "<memorytune vcpus='%s'", vcpus);
+
+    if (!(flags & VIR_DOMAIN_DEF_FORMAT_INACTIVE)) {
+        const char *alloc_id = virResctrlAllocGetID(resctrl->alloc);
+        if (!alloc_id)
+            goto cleanup;
+
+        virBufferAsprintf(buf, " id='%s'", alloc_id);
+    }
+    virBufferAddLit(buf, ">\n");
+
+    virBufferAddBuffer(buf, &childrenBuf);
+    virBufferAddLit(buf, "</memorytune>\n");
+
+    ret = 0;
+ cleanup:
+    virBufferFreeAndReset(&childrenBuf);
+    VIR_FREE(vcpus);
+    return ret;
+}
+
 static int
 virDomainCputuneDefFormat(virBufferPtr buf,
                           virDomainDefPtr def,
@@ -27303,6 +27500,9 @@ virDomainCputuneDefFormat(virBufferPtr buf,
     for (i = 0; i < def->nresctrls; i++)
         virDomainCachetuneDefFormat(&childrenBuf, def->resctrls[i], flags);
 
+    for (i = 0; i < def->nresctrls; i++)
+        virDomainMemorytuneDefFormat(&childrenBuf, def->resctrls[i], flags);
+
     if (virBufferCheckError(&childrenBuf) < 0)
         return -1;
 

tests/genericxml2xmlindata/memorytune-colliding-allocs.xml

@@ -0,0 +1,30 @@
+<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'>4</vcpu>
+  <cputune>
+    <memorytune vcpus='0'>
+      <node id='0' bandwidth='50'/>
+      <node id='0' bandwidth='50'/>
+    </memorytune>
+  </cputune>
+  <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-system-i686</emulator>
+    <controller type='usb' index='0'/>
+    <controller type='ide' index='0'/>
+    <controller type='pci' index='0' model='pci-root'/>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>

tests/genericxml2xmlindata/memorytune-colliding-cachetune.xml

@@ -0,0 +1,32 @@
+<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'>4</vcpu>
+  <cputune>
+    <cachetune vcpus='0-1'>
+      <cache id='0' level='3' type='code' size='12' unit='KiB'/>
+    </cachetune>
+    <memorytune vcpus='0'>
+      <node id='0' bandwidth='50'/>
+    </memorytune>
+  </cputune>
+  <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-system-i686</emulator>
+    <controller type='usb' index='0'/>
+    <controller type='ide' index='0'/>
+    <controller type='pci' index='0' model='pci-root'/>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>

tests/genericxml2xmlindata/memorytune.xml

@@ -0,0 +1,33 @@
+<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'>4</vcpu>
+  <cputune>
+    <memorytune vcpus='0-1'>
+      <node id='0' bandwidth='20'/>
+      <node id='1' bandwidth='30'/>
+    </memorytune>
+    <memorytune vcpus='3'>
+      <node id='0' bandwidth='50'/>
+    </memorytune>
+  </cputune>
+  <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-system-i686</emulator>
+    <controller type='usb' index='0'/>
+    <controller type='ide' index='0'/>
+    <controller type='pci' index='0' model='pci-root'/>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>

tests/genericxml2xmltest.c

@@ -140,6 +140,11 @@ mymain(void)
                  TEST_COMPARE_DOM_XML2XML_RESULT_FAIL_PARSE);
     DO_TEST_FULL("cachetune-colliding-types", false, true,
                  TEST_COMPARE_DOM_XML2XML_RESULT_FAIL_PARSE);
+    DO_TEST("memorytune");
+    DO_TEST_FULL("memorytune-colliding-allocs", false, true,
+                 TEST_COMPARE_DOM_XML2XML_RESULT_FAIL_PARSE);
+    DO_TEST_FULL("memorytune-colliding-cachetune", false, true,
+                 TEST_COMPARE_DOM_XML2XML_RESULT_FAIL_PARSE);
 
     DO_TEST("tseg");