conf: Add support for cputune/cachetune

More info in the documentation, this is basically the XML parsing/formatting
support, schemas, tests and documentation for the new cputune/cachetune element
that will get used by following patches.

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

docs/formatdomain.html.in

@@ -702,6 +702,10 @@
     <iothread_quota>-1</iothread_quota>
     <vcpusched vcpus='0-4,^3' scheduler='fifo' priority='1'/>
     <iothreadsched iothreads='2' scheduler='batch'/>
+    <cachetune vcpus='0-3'>
+      <cache id='0' level='3' type='both' size='3' unit='MiB'/>
+      <cache id='1' level='3' type='both' size='3' unit='MiB'/>
+    </cachetune>
   </cputune>
   ...
 </domain>
@@ -847,6 +851,56 @@
         <span class="since">Since 1.2.13</span>
       </dd>
 
+      <dt><code>cachetune</code><span class="since">Since 4.1.0</span></dt>
+      <dd>
+        Optional <code>cachetune</code> element can control allocations for CPU
+        caches using the resctrl on the host. Whether or not is this supported
+        can be gathered from capabilities where some limitations like minimum
+        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:
+        <dl>
+          <dt><code>cache</code></dt>
+          <dd>
+            This element controls the allocation of CPU cache and has the
+            following attributes:
+            <dl>
+              <dt><code>level</code></dt>
+              <dd>
+                Host cache level from which to allocate.
+              </dd>
+              <dt><code>id</code></dt>
+              <dd>
+                Host cache id from which to allocate.
+              </dd>
+              <dt><code>type</code></dt>
+              <dd>
+                Type of allocation. Can be <code>code</code> for code
+                (instructions), <code>data</code> for data or <code>both</code>
+                for both code and data (unified). Currently the allocation can
+                be done only with the same type as the host supports, meaning
+                you cannot request <code>both</code> for host with CDP
+                (code/data prioritization) enabled.
+              </dd>
+              <dt><code>size</code></dt>
+              <dd>
+                The size of the region to allocate. The value by default is in
+                bytes, but the <code>unit</code> attribute can be used to scale
+                the value.
+              </dd>
+              <dt><code>unit</code> (optional)</dt>
+              <dd>
+                If specified it is the unit such as KiB, MiB, GiB, or TiB
+                (described in the <code>memory</code> element
+                for <a href="#elementsMemoryAllocation">Memory Allocation</a>)
+                in which <code>size</code> is specified, defaults to bytes.
+              </dd>
+            </dl>
+          </dd>
+        </dl>
+
+      </dd>
     </dl>
 
 

docs/schemas/domaincommon.rng

@@ -900,6 +900,38 @@
             <ref name="schedparam"/>
           </element>
         </zeroOrMore>
+        <zeroOrMore>
+          <element name="cachetune">
+            <attribute name="vcpus">
+              <ref name='cpuset'/>
+            </attribute>
+            <oneOrMore>
+              <element name="cache">
+                <attribute name="id">
+                  <ref name='unsignedInt'/>
+                </attribute>
+                <attribute name="level">
+                  <ref name='unsignedInt'/>
+                </attribute>
+                <attribute name="type">
+                  <choice>
+                    <value>both</value>
+                    <value>code</value>
+                    <value>data</value>
+                  </choice>
+                </attribute>
+                <attribute name="size">
+                  <ref name='unsignedLong'/>
+                </attribute>
+                <optional>
+                  <attribute name='unit'>
+                    <ref name='unit'/>
+                  </attribute>
+                </optional>
+              </element>
+            </oneOrMore>
+          </element>
+        </zeroOrMore>
       </interleave>
     </element>
   </define>

src/conf/domain_conf.c

@@ -2883,6 +2883,19 @@ virDomainLoaderDefFree(virDomainLoaderDefPtr loader)
     VIR_FREE(loader);
 }
 
+
+static void
+virDomainCachetuneDefFree(virDomainCachetuneDefPtr cachetune)
+{
+    if (!cachetune)
+        return;
+
+    virObjectUnref(cachetune->alloc);
+    virBitmapFree(cachetune->vcpus);
+    VIR_FREE(cachetune);
+}
+
+
 void virDomainDefFree(virDomainDefPtr def)
 {
     size_t i;
@@ -3055,6 +3068,10 @@ void virDomainDefFree(virDomainDefPtr def)
         virDomainShmemDefFree(def->shmems[i]);
     VIR_FREE(def->shmems);
 
+    for (i = 0; i < def->ncachetunes; i++)
+        virDomainCachetuneDefFree(def->cachetunes[i]);
+    VIR_FREE(def->cachetunes);
+
     VIR_FREE(def->keywrap);
 
     if (def->namespaceData && def->ns.free)
@@ -18294,6 +18311,194 @@ virDomainDefParseBootOptions(virDomainDefPtr def,
 }
 
 
+static int
+virDomainCachetuneDefParseCache(xmlXPathContextPtr ctxt,
+                                xmlNodePtr node,
+                                virResctrlAllocPtr alloc)
+{
+    xmlNodePtr oldnode = ctxt->node;
+    unsigned int level;
+    unsigned int cache;
+    int type;
+    unsigned long long size;
+    char *tmp = NULL;
+    int ret = -1;
+
+    ctxt->node = node;
+
+    tmp = virXMLPropString(node, "id");
+    if (!tmp) {
+        virReportError(VIR_ERR_XML_ERROR, "%s",
+                       _("Missing cachetune attribute 'id'"));
+        goto cleanup;
+    }
+    if (virStrToLong_uip(tmp, NULL, 10, &cache) < 0) {
+        virReportError(VIR_ERR_XML_ERROR,
+                       _("Invalid cachetune attribute 'id' value '%s'"),
+                       tmp);
+        goto cleanup;
+    }
+    VIR_FREE(tmp);
+
+    tmp = virXMLPropString(node, "level");
+    if (!tmp) {
+        virReportError(VIR_ERR_XML_ERROR, "%s",
+                       _("Missing cachetune attribute 'level'"));
+        goto cleanup;
+    }
+    if (virStrToLong_uip(tmp, NULL, 10, &level) < 0) {
+        virReportError(VIR_ERR_XML_ERROR,
+                       _("Invalid cachetune attribute 'level' value '%s'"),
+                       tmp);
+        goto cleanup;
+    }
+    VIR_FREE(tmp);
+
+    tmp = virXMLPropString(node, "type");
+    if (!tmp) {
+        virReportError(VIR_ERR_XML_ERROR, "%s",
+                       _("Missing cachetune attribute 'type'"));
+        goto cleanup;
+    }
+    type = virCacheTypeFromString(tmp);
+    if (type < 0) {
+        virReportError(VIR_ERR_XML_ERROR,
+                       _("Invalid cachetune attribute 'type' value '%s'"),
+                       tmp);
+        goto cleanup;
+    }
+    VIR_FREE(tmp);
+
+    if (virDomainParseScaledValue("./@size", "./@unit",
+                                  ctxt, &size, 1024,
+                                  ULLONG_MAX, true) < 0)
+        goto cleanup;
+
+    if (virResctrlAllocSetSize(alloc, level, type, cache, size) < 0)
+        goto cleanup;
+
+    ret = 0;
+ cleanup:
+    ctxt->node = oldnode;
+    VIR_FREE(tmp);
+    return ret;
+}
+
+
+static int
+virDomainCachetuneDefParse(virDomainDefPtr def,
+                           xmlXPathContextPtr ctxt,
+                           xmlNodePtr node,
+                           unsigned int flags)
+{
+    xmlNodePtr oldnode = ctxt->node;
+    xmlNodePtr *nodes = NULL;
+    virBitmapPtr vcpus = NULL;
+    virResctrlAllocPtr alloc = virResctrlAllocNew();
+    virDomainCachetuneDefPtr tmp_cachetune = NULL;
+    char *tmp = NULL;
+    char *vcpus_str = NULL;
+    char *alloc_id = NULL;
+    ssize_t i = 0;
+    int n;
+    int ret = -1;
+
+    ctxt->node = node;
+
+    if (!alloc)
+        goto cleanup;
+
+    if (VIR_ALLOC(tmp_cachetune) < 0)
+        goto cleanup;
+
+    vcpus_str = virXMLPropString(node, "vcpus");
+    if (!vcpus_str) {
+        virReportError(VIR_ERR_XML_ERROR, "%s",
+                       _("Missing cachetune attribute 'vcpus'"));
+        goto cleanup;
+    }
+    if (virBitmapParse(vcpus_str, &vcpus, VIR_DOMAIN_CPUMASK_LEN) < 0) {
+        virReportError(VIR_ERR_XML_ERROR,
+                       _("Invalid cachetune attribute 'vcpus' value '%s'"),
+                       vcpus_str);
+        goto cleanup;
+    }
+
+    /* We need to limit the bitmap to number of vCPUs.  If there's nothing left,
+     * then we can just clean up and return 0 immediately */
+    virBitmapShrink(vcpus, def->maxvcpus);
+    if (virBitmapIsAllClear(vcpus)) {
+        ret = 0;
+        goto cleanup;
+    }
+
+    if ((n = virXPathNodeSet("./cache", ctxt, &nodes)) < 0) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("Cannot extract cache nodes under cachetune"));
+        goto cleanup;
+    }
+
+    for (i = 0; i < n; i++) {
+        if (virDomainCachetuneDefParseCache(ctxt, nodes[i], alloc) < 0)
+            goto cleanup;
+    }
+
+    if (virResctrlAllocIsEmpty(alloc)) {
+        ret = 0;
+        goto cleanup;
+    }
+
+    for (i = 0; i < def->ncachetunes; i++) {
+        if (virBitmapOverlaps(def->cachetunes[i]->vcpus, vcpus)) {
+            virReportError(VIR_ERR_XML_ERROR, "%s",
+                           _("Overlapping vcpus in cachetunes"));
+            goto cleanup;
+        }
+    }
+
+    /* We need to format it back because we need to be consistent in the naming
+     * even when users specify some "sub-optimal" string there. */
+    VIR_FREE(vcpus_str);
+    vcpus_str = virBitmapFormat(vcpus);
+    if (!vcpus_str)
+        goto cleanup;
+
+    if (!(flags & VIR_DOMAIN_DEF_PARSE_INACTIVE))
+        alloc_id = virXMLPropString(node, "id");
+
+    if (!alloc_id) {
+        /* The number of allocations is limited and the directory structure is flat,
+         * not hierarchical, so we need to have all same allocations in one
+         * directory, so it's nice to have it named appropriately.  For now it's
+         * 'vcpus_...' but it's designed in order for it to be changeable in the
+         * future (it's part of the status XML). */
+        if (virAsprintf(&alloc_id, "vcpus_%s", vcpus_str) < 0)
+            goto cleanup;
+    }
+
+    if (virResctrlAllocSetID(alloc, alloc_id) < 0)
+        goto cleanup;
+
+    VIR_STEAL_PTR(tmp_cachetune->vcpus, vcpus);
+    VIR_STEAL_PTR(tmp_cachetune->alloc, alloc);
+
+    if (VIR_APPEND_ELEMENT(def->cachetunes, def->ncachetunes, tmp_cachetune) < 0)
+        goto cleanup;
+
+    ret = 0;
+ cleanup:
+    ctxt->node = oldnode;
+    virDomainCachetuneDefFree(tmp_cachetune);
+    virObjectUnref(alloc);
+    virBitmapFree(vcpus);
+    VIR_FREE(alloc_id);
+    VIR_FREE(vcpus_str);
+    VIR_FREE(nodes);
+    VIR_FREE(tmp);
+    return ret;
+}
+
+
 static virDomainDefPtr
 virDomainDefParseXML(xmlDocPtr xml,
                      xmlNodePtr root,
@@ -18846,6 +19051,18 @@ virDomainDefParseXML(xmlDocPtr xml,
     }
     VIR_FREE(nodes);
 
+    if ((n = virXPathNodeSet("./cputune/cachetune", ctxt, &nodes)) < 0) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("cannot extract cachetune nodes"));
+        goto error;
+    }
+
+    for (i = 0; i < n; i++) {
+        if (virDomainCachetuneDefParse(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;
 
@@ -25797,9 +26014,80 @@ virDomainSchedulerFormat(virBufferPtr buf,
 }
 
 
+static int
+virDomainCachetuneDefFormatHelper(unsigned int level,
+                                  virCacheType type,
+                                  unsigned int cache,
+                                  unsigned long long size,
+                                  void *opaque)
+{
+    const char *unit;
+    virBufferPtr buf = opaque;
+    unsigned long long short_size = virFormatIntPretty(size, &unit);
+
+    virBufferAsprintf(buf,
+                      "<cache id='%u' level='%u' type='%s' "
+                      "size='%llu' unit='%s'/>\n",
+                      cache, level, virCacheTypeToString(type),
+                      short_size, unit);
+
+    return 0;
+}
+
+
+static int
+virDomainCachetuneDefFormat(virBufferPtr buf,
+                            virDomainCachetuneDefPtr cachetune,
+                            unsigned int flags)
+{
+    virBuffer childrenBuf = VIR_BUFFER_INITIALIZER;
+    char *vcpus = NULL;
+    int ret = -1;
+
+    virBufferSetChildIndent(&childrenBuf, buf);
+    virResctrlAllocForeachSize(cachetune->alloc,
+                               virDomainCachetuneDefFormatHelper,
+                               &childrenBuf);
+
+
+    if (virBufferCheckError(&childrenBuf) < 0)
+        goto cleanup;
+
+    if (!virBufferUse(&childrenBuf)) {
+        ret = 0;
+        goto cleanup;
+    }
+
+    vcpus = virBitmapFormat(cachetune->vcpus);
+    if (!vcpus)
+        goto cleanup;
+
+    virBufferAsprintf(buf, "<cachetune vcpus='%s'", vcpus);
+
+    if (!(flags & VIR_DOMAIN_DEF_FORMAT_INACTIVE)) {
+        const char *alloc_id = virResctrlAllocGetID(cachetune->alloc);
+        if (!alloc_id)
+            goto cleanup;
+
+        virBufferAsprintf(buf, " id='%s'", alloc_id);
+    }
+    virBufferAddLit(buf, ">\n");
+
+    virBufferAddBuffer(buf, &childrenBuf);
+    virBufferAddLit(buf, "</cachetune>\n");
+
+    ret = 0;
+ cleanup:
+    virBufferFreeAndReset(&childrenBuf);
+    VIR_FREE(vcpus);
+    return ret;
+}
+
+
 static int
 virDomainCputuneDefFormat(virBufferPtr buf,
-                          virDomainDefPtr def)
+                          virDomainDefPtr def,
+                          unsigned int flags)
 {
     size_t i;
     virBuffer childrenBuf = VIR_BUFFER_INITIALIZER;
@@ -25898,6 +26186,9 @@ virDomainCputuneDefFormat(virBufferPtr buf,
                                  def->iothreadids[i]->iothread_id);
     }
 
+    for (i = 0; i < def->ncachetunes; i++)
+        virDomainCachetuneDefFormat(&childrenBuf, def->cachetunes[i], flags);
+
     if (virBufferCheckError(&childrenBuf) < 0)
         return -1;
 
@@ -26235,7 +26526,7 @@ virDomainDefFormatInternal(virDomainDefPtr def,
         }
     }
 
-    if (virDomainCputuneDefFormat(buf, def) < 0)
+    if (virDomainCputuneDefFormat(buf, def, flags) < 0)
         goto error;
 
     if (virDomainNumatuneFormatXML(buf, def->numa) < 0)

src/conf/domain_conf.h

@@ -56,6 +56,7 @@
 # include "virperf.h"
 # include "virtypedparam.h"
 # include "virsavecookie.h"
+# include "virresctrl.h"
 
 /* forward declarations of all device types, required by
  * virDomainDeviceDef
@@ -2194,6 +2195,15 @@ struct _virDomainCputune {
 };
 
 
+typedef struct _virDomainCachetuneDef virDomainCachetuneDef;
+typedef virDomainCachetuneDef *virDomainCachetuneDefPtr;
+
+struct _virDomainCachetuneDef {
+    virBitmapPtr vcpus;
+    virResctrlAllocPtr alloc;
+};
+
+
 typedef struct _virDomainVcpuDef virDomainVcpuDef;
 typedef virDomainVcpuDef *virDomainVcpuDefPtr;
 
@@ -2322,6 +2332,9 @@ struct _virDomainDef {
 
     virDomainCputune cputune;
 
+    virDomainCachetuneDefPtr *cachetunes;
+    size_t ncachetunes;
+
     virDomainNumaPtr numa;
     virDomainResourceDefPtr resource;
     virDomainIdMapDef idmap;

tests/genericxml2xmlindata/cachetune-cdp.xml

@@ -0,0 +1,36 @@
+<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='7680' unit='KiB'/>
+      <cache id='1' level='3' type='data' size='3840' unit='KiB'/>
+    </cachetune>
+    <cachetune vcpus='2'>
+      <cache id='1' level='3' type='code' size='6' unit='MiB'/>
+    </cachetune>
+    <cachetune vcpus='3'>
+      <cache id='1' level='3' type='data' size='6912' unit='KiB'/>
+    </cachetune>
+  </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/cachetune-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>
+    <cachetune vcpus='0'>
+      <cache id='0' level='3' type='code' size='12' unit='KiB'/>
+      <cache id='0' level='3' type='code' size='18' unit='KiB'/>
+    </cachetune>
+  </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/cachetune-colliding-tunes.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'>
+      <cache id='0' level='3' type='code' size='12' unit='KiB'/>
+    </cachetune>
+    <cachetune vcpus='0'>
+      <cache id='0' level='3' type='data' size='18' unit='KiB'/>
+    </cachetune>
+  </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/cachetune-colliding-types.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>
+    <cachetune vcpus='0-1'>
+      <cache id='0' level='3' type='both' size='12' unit='KiB'/>
+      <cache id='0' level='3' type='code' size='6' unit='KiB'/>
+    </cachetune>
+  </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/cachetune-small.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'>4</vcpu>
+  <cputune>
+    <cachetune vcpus='0-1'>
+      <cache id='0' level='3' type='both' size='768' unit='KiB'/>
+    </cachetune>
+  </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/cachetune.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>
+    <cachetune vcpus='0-1'>
+      <cache id='0' level='3' type='both' size='3' unit='MiB'/>
+      <cache id='1' level='3' type='both' size='3' unit='MiB'/>
+    </cachetune>
+    <cachetune vcpus='3'>
+      <cache id='0' level='3' type='both' size='3' unit='MiB'/>
+    </cachetune>
+  </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

@@ -130,6 +130,16 @@ mymain(void)
     DO_TEST_FULL("chardev-reconnect-invalid-mode", 0, false,
                  TEST_COMPARE_DOM_XML2XML_RESULT_FAIL_PARSE);
 
+    DO_TEST("cachetune");
+    DO_TEST("cachetune-small");
+    DO_TEST("cachetune-cdp");
+    DO_TEST_FULL("cachetune-colliding-allocs", false, true,
+                 TEST_COMPARE_DOM_XML2XML_RESULT_FAIL_PARSE);
+    DO_TEST_FULL("cachetune-colliding-tunes", false, true,
+                 TEST_COMPARE_DOM_XML2XML_RESULT_FAIL_PARSE);
+    DO_TEST_FULL("cachetune-colliding-types", false, true,
+                 TEST_COMPARE_DOM_XML2XML_RESULT_FAIL_PARSE);
+
     virObjectUnref(caps);
     virObjectUnref(xmlopt);