Re: [libvirt] [PATCH v2 04/10] conf: Introduce memAccess to <memory/>

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(a)redhat.com&gt; --- 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> ... &lt;devices&gt; - &lt;memory model='dimm'&gt; + &lt;memory model='dimm' memAccess='private'&gt;

&lt;target&gt; &lt;size unit='KiB'&gt;524287&lt;/size&gt; &lt;node&gt;0&lt;/node&gt; @@ -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 &lt;cell/&gt;: + <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>