Document and parser support for the Virtio free page reporting feature.

This will add the proper documentation and parser support for the free page
reporting feature that is introduced in QEMU 5.1.

Signed-off-by: Nico Pache <npache@redhat.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst
index df5ac280285108ebff7f370d2776685a69670a80..83dec62f30356eea8b1fb6f11ded169b99c0a6c4 100644 (file)
--- a/docs/formatdomain.rst
+++ b/docs/formatdomain.rst
@@ -6755,6 +6755,12 @@ Example: manually added device with static PCI slot 2 requested
    release some memory at the last moment before a guest's process get killed by
    Out of Memory killer. :since:`Since 1.3.1, QEMU and KVM only`
 
+``free-page-reporting``
+   The optional ``free-page-reporting`` attribute allows to enable/disable
+   ("on"/"off", respectively) the ability of the QEMU virtio memory balloon to
+   return unused pages back to the hypervisor to be used by other guests or
+   processes. :since:`Since 6.9.0, QEMU and KVM only`
+
 ``period``
    The optional ``period`` allows the QEMU virtio memory balloon driver to
    provide statistics through the ``virsh dommemstat           [domain]``

diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index 7d4b105981e8b2eb69426167f1b2c6fee00f8e0c..0a0f0ed8a811b2a00e5898e86f50400546eca427 100644 (file)
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -4539,6 +4539,11 @@
           <ref name="virOnOff"/>
         </attribute>
       </optional>
+      <optional>
+         <attribute name="free-page-reporting">
+           <ref name="virOnOff"/>
+         </attribute>
+       </optional>
       <interleave>
         <optional>
           <ref name="alias"/>

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 51efeb0e42fbb2cd95e8748e9666485f21124a4d..1d3661c21f10edc14820579a95cc3abcc94d6699 100644 (file)
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -15336,6 +15336,7 @@ virDomainMemballoonDefParseXML(virDomainXMLOptionPtr xmlopt,
     VIR_XPATH_NODE_AUTORESTORE(ctxt)
     unsigned int period = 0;
     g_autofree char *model = NULL;
+    g_autofree char *freepage_reporting = NULL;
     g_autofree char *deflate = NULL;
 
     def = g_new0(virDomainMemballoonDef, 1);
@@ -15360,6 +15361,13 @@ virDomainMemballoonDefParseXML(virDomainXMLOptionPtr xmlopt,
         goto error;
     }
 
+    if ((freepage_reporting = virXMLPropString(node, "free-page-reporting")) &&
+        (def->free_page_reporting = virTristateSwitchTypeFromString(freepage_reporting)) <= 0) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                       _("invalid free-page-reporting attribute value '%s'"), freepage_reporting);
+        goto error;
+    }
+
     ctxt->node = node;
     if (virXPathUInt("string(./stats/@period)", ctxt, &period) < -1) {
         virReportError(VIR_ERR_XML_ERROR, "%s",
@@ -23538,6 +23546,15 @@ virDomainMemballoonDefCheckABIStability(virDomainMemballoonDefPtr src,
         return false;
     }
 
+    if (src->free_page_reporting != dst->free_page_reporting) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                       _("Target balloon free-page-reporting attribute value "
+                         "'%s' does not match source '%s'"),
+                       virTristateSwitchTypeToString(dst->free_page_reporting),
+                       virTristateSwitchTypeToString(src->free_page_reporting));
+        return false;
+    }
+
     if (src->virtio && dst->virtio &&
         !virDomainVirtioOptionsCheckABIStability(src->virtio, dst->virtio))
         return false;
@@ -27644,6 +27661,10 @@ virDomainMemballoonDefFormat(virBufferPtr buf,
         virBufferAsprintf(&attrBuf, " autodeflate='%s'",
                           virTristateSwitchTypeToString(def->autodeflate));
 
+    if (def->free_page_reporting != VIR_TRISTATE_SWITCH_ABSENT)
+        virBufferAsprintf(&attrBuf, " free-page-reporting='%s'",
+                          virTristateSwitchTypeToString(def->free_page_reporting));
+
     if (def->period)
         virBufferAsprintf(&childrenBuf, "<stats period='%i'/>\n", def->period);
 

diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 450686dfb5b1099d1c0277aa9ce810250189969d..902dd58112c205f109a308bce2ed08eedcdf0ffb 100644 (file)
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -1790,6 +1790,7 @@ struct _virDomainMemballoonDef {
     virDomainDeviceInfo info;
     int period; /* seconds between collections */
     int autodeflate; /* enum virTristateSwitch */
+    int free_page_reporting; /* enum virTristateSwitch */
     virDomainVirtioOptionsPtr virtio;
 };