Now that NVDIMM has found its way into libvirt, users might want
to fine tune some settings for each module separately. One such
setting is 'share=on|off' for the memory-backend-file object.
This setting - just like its name suggest already - enables
sharing the nvdimm module with other applications. Under the hood
it controls whether qemu mmaps() the file as MAP_PRIVATE or
MAP_SHARED.
Yet again, we have such config knob in domain XML, but it's just
an attribute to numa <cell/>. This does not give fine enough
tuning on per-memdevice basis so we need to have the attribute
for each device too.
Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx>
---
docs/formatdomain.html.in | 15 ++++++-
docs/schemas/domaincommon.rng | 19 ++++++---
src/conf/domain_conf.c | 15 ++++++-
src/conf/domain_conf.h | 2 +
src/libvirt_private.syms | 2 +
...emuxml2argv-memory-hotplug-nvdimm-memAccess.xml | 49 ++++++++++++++++++++++
6 files changed, 93 insertions(+), 9 deletions(-)
create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-memory-hotplug-nvdimm-memAccess.xml
diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index 657df8f..06fe50d 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -1356,7 +1356,7 @@
<span class='since'>Since 1.2.9</span> the optional attribute
<code>memAccess</code> can control whether the memory is to be
mapped as "shared" or "private". This is valid only for
- hugepages-backed memory.
+ hugepages-backed memory and nvdimm modules.
</p>
<p>
@@ -6724,7 +6724,7 @@ qemu-kvm -net nic,model=? /dev/null
<pre>
...
<devices>
- <memory model='dimm'>
+ <memory model='dimm' memAccess='private'>
<target>
<size unit='KiB'>524287</size>
<node>0</node>
@@ -6762,6 +6762,17 @@ qemu-kvm -net nic,model=? /dev/null
</p>
</dd>
+ <dt><code>memAccess</code></dt>
+ <dd>
+ <p>
+ Then there is optional attribute <code>memAccess</code>
+ (<span class="since">Since 2.2.0</span>) that allows
+ uses to fine tune mapping of the memory on per module
+ basis. Values are the same as for numa <cell/>:
+ <code>shared</code> and <code>private</code>.
+ </p>
+ </dd>
+
<dt><code>source</code></dt>
<dd>
<p>
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index e6ad452..3e9d342 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -4467,6 +4467,15 @@
</element>
</define>
+ <define name="memAccess">
+ <attribute name="memAccess">
+ <choice>
+ <value>shared</value>
+ <value>private</value>
+ </choice>
+ </attribute>
+ </define>
+
<define name="numaCell">
<element name="cell">
<optional>
@@ -4486,12 +4495,7 @@
</attribute>
</optional>
<optional>
- <attribute name="memAccess">
- <choice>
- <value>shared</value>
- <value>private</value>
- </choice>
- </attribute>
+ <ref name="memAccess"/>
</optional>
</element>
</define>
@@ -4725,6 +4729,9 @@
<value>nvdimm</value>
</choice>
</attribute>
+ <optional>
+ <ref name="memAccess"/>
+ </optional>
<interleave>
<optional>
<ref name="memorydev-source"/>
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index cb5a053..84f76dd 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -13245,6 +13245,15 @@ virDomainMemoryDefParseXML(xmlNodePtr memdevNode,
}
VIR_FREE(tmp);
+ tmp = virXMLPropString(memdevNode, "memAccess");
+ if (tmp &&
+ (def->memAccess = virNumaMemAccessTypeFromString(tmp)) <= 0) {
+ virReportError(VIR_ERR_XML_ERROR,
+ _("invalid memAccess mode '%s'"), tmp);
+ goto error;
+ }
+ VIR_FREE(tmp);
+
/* source */
if ((node = virXPathNode("./source", ctxt)) &&
virDomainMemorySourceDefParseXML(node, ctxt, def) < 0)
@@ -21800,7 +21809,11 @@ virDomainMemoryDefFormat(virBufferPtr buf,
{
const char *model = virDomainMemoryModelTypeToString(def->model);
- virBufferAsprintf(buf, "<memory model='%s'>\n", model);
+ virBufferAsprintf(buf, "<memory model='%s'", model);
+ if (def->memAccess)
+ virBufferAsprintf(buf, " memAccess='%s'",
+ virNumaMemAccessTypeToString(def->memAccess));
+ virBufferAddLit(buf, ">\n");
virBufferAdjustIndent(buf, 2);
if (virDomainMemorySourceDefFormat(buf, def) < 0)
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 4e6a9bf..213768d 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -1945,6 +1945,8 @@ typedef enum {
} virDomainMemoryModel;
struct _virDomainMemoryDef {
+ virNumaMemAccess memAccess;
+
/* source */
virBitmapPtr sourceNodes;
unsigned long long pagesize; /* kibibytes */
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 419c33d..024c3e6 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -2058,6 +2058,8 @@ virNumaGetNodeMemory;
virNumaGetPageInfo;
virNumaGetPages;
virNumaIsAvailable;
+virNumaMemAccessTypeFromString;
+virNumaMemAccessTypeToString;
virNumaNodeIsAvailable;
virNumaNodesetIsAvailable;
virNumaSetPagePoolSize;
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-memory-hotplug-nvdimm-memAccess.xml b/tests/qemuxml2argvdata/qemuxml2argv-memory-hotplug-nvdimm-memAccess.xml
new file mode 100644
index 0000000..4ebea01
--- /dev/null
+++ b/tests/qemuxml2argvdata/qemuxml2argv-memory-hotplug-nvdimm-memAccess.xml
@@ -0,0 +1,49 @@
+<domain type='qemu'>
+ <name>QEMUGuest1</name>
+ <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+ <maxMemory slots='16' unit='KiB'>1099511627776</maxMemory>
+ <memory unit='KiB'>1267710</memory>
+ <currentMemory unit='KiB'>1267710</currentMemory>
+ <vcpu placement='static' cpuset='0-1'>2</vcpu>
+ <os>
+ <type arch='i686' machine='pc'>hvm</type>
+ <boot dev='hd'/>
+ </os>
+ <idmap>
+ <uid start='0' target='1000' count='10'/>
+ <gid start='0' target='1000' count='10'/>
+ </idmap>
+ <cpu>
+ <topology sockets='2' cores='1' threads='1'/>
+ <numa>
+ <cell id='0' cpus='0-1' memory='219136' unit='KiB'/>
+ </numa>
+ </cpu>
+ <clock offset='utc'/>
+ <on_poweroff>destroy</on_poweroff>
+ <on_reboot>restart</on_reboot>
+ <on_crash>destroy</on_crash>
+ <devices>
+ <emulator>/usr/bin/qemu</emulator>
+ <disk type='block' device='disk'>
+ <source dev='/dev/HostVG/QEMUGuest1'/>
+ <target dev='hda' bus='ide'/>
+ <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+ </disk>
+ <controller type='ide' index='0'/>
+ <controller type='usb' index='0'/>
+ <controller type='pci' index='0' model='pci-root'/>
+ <input type='mouse' bus='ps2'/>
+ <input type='keyboard' bus='ps2'/>
+ <memballoon model='virtio'/>
+ <memory model='nvdimm' memAccess='private'>
+ <source>
+ <path>/tmp/nvdimm</path>
+ </source>
+ <target>
+ <size unit='KiB'>523264</size>
+ <node>0</node>
+ </target>
+ </memory>
+ </devices>
+</domain>
--
2.8.4
--
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