[libvirt] [PATCH v2 05/14] conf: Introduce @access to <memory/>
John Ferlan
jferlan at redhat.com
Tue Mar 7 16:23:30 UTC 2017
On 02/27/2017 08:19 AM, Michal Privoznik wrote:
> 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 at redhat.com>
> ---
> docs/formatdomain.html.in | 15 +++++-
> docs/schemas/domaincommon.rng | 8 ++++
> src/conf/domain_conf.c | 15 +++++-
> src/conf/domain_conf.h | 2 +
> .../qemuxml2argv-memory-hotplug-nvdimm-access.xml | 56 ++++++++++++++++++++++
> ...qemuxml2xmlout-memory-hotplug-nvdimm-access.xml | 1 +
> tests/qemuxml2xmltest.c | 1 +
> 7 files changed, 95 insertions(+), 3 deletions(-)
> create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-memory-hotplug-nvdimm-access.xml
> create mode 120000 tests/qemuxml2xmloutdata/qemuxml2xmlout-memory-hotplug-nvdimm-access.xml
>
> diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
> index b76905cdc..00c0df2ce 100644
> --- a/docs/formatdomain.html.in
> +++ b/docs/formatdomain.html.in
> @@ -1406,7 +1406,7 @@
> <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>
> @@ -7015,7 +7015,7 @@ qemu-kvm -net nic,model=? /dev/null
> <pre>
> ...
> <devices>
> - <memory model='dimm'>
> + <memory model='dimm' access='private'>
Hmmm... this type of change almost makes it seem as though access will
be required or written out always now.
> <target>
> <size unit='KiB'>524287</size>
> <node>0</node>
> @@ -7054,6 +7054,17 @@ qemu-kvm -net nic,model=? /dev/null
> </p>
> </dd>
>
> + <dt><code>access</code></dt>
> + <dd>
> + <p>
> + Then there is optional attribute <code>access</code>
s/Then there is optional/An optional
> + (<span class="since">Since 3.1.0</span>) that allows
It'll be "since 3.2.0" at the earliest (don't capitalize Since in the
middle of a sentence)
> + uses to fine tune mapping of the memory on per module
s/allows uses to/provides the capability to/
> + basis. Values are the same as for numa <cell/>:
> + <code>shared</code> and <code>private</code>.
It's perhaps a nit, but I guess I just read the docs literally rather
than interpretively... The "access mode='shared|private'" shows up in
the "Memory Backing" section even though there's a NUMA Node Tuning
section later. So, I would change "for numa <cell>" to include "Memory
Backing" and a link to that, e.g.
<a href="#elementsMemoryBacking">Memory Backing</a>
within the text
> + </p>
> + </dd>
> +
> <dt><code>source</code></dt>
> <dd>
> <p>
> diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
> index fafd3e982..78195aae9 100644
> --- a/docs/schemas/domaincommon.rng
> +++ b/docs/schemas/domaincommon.rng
> @@ -4740,6 +4740,14 @@
> <value>nvdimm</value>
> </choice>
> </attribute>
> + <optional>
> + <attribute name="access">
> + <choice>
> + <value>shared</value>
> + <value>private</value>
> + </choice>
> + </attribute>
> + </optional>
> <interleave>
> <optional>
> <ref name="memorydev-source"/>
> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
> index 4ffca7dc8..a31114cc7 100644
> --- a/src/conf/domain_conf.c
> +++ b/src/conf/domain_conf.c
> @@ -13860,6 +13860,15 @@ virDomainMemoryDefParseXML(xmlNodePtr memdevNode,
> }
> VIR_FREE(tmp);
>
> + tmp = virXMLPropString(memdevNode, "access");
> + if (tmp &&
> + (def->access = virDomainMemoryAccessTypeFromString(tmp)) <= 0) {
> + virReportError(VIR_ERR_XML_ERROR,
> + _("invalid access mode '%s'"), tmp);
> + goto error;
> + }
> + VIR_FREE(tmp);
> +
> /* source */
> if ((node = virXPathNode("./source", ctxt)) &&
> virDomainMemorySourceDefParseXML(node, ctxt, def) < 0)
> @@ -22666,7 +22675,11 @@ virDomainMemoryDefFormat(virBufferPtr buf,
> {
> const char *model = virDomainMemoryModelTypeToString(def->model);
>
> - virBufferAsprintf(buf, "<memory model='%s'>\n", model);
> + virBufferAsprintf(buf, "<memory model='%s'", model);
> + if (def->access)
> + virBufferAsprintf(buf, " access='%s'",
> + virDomainMemoryAccessTypeToString(def->access));
> + virBufferAddLit(buf, ">\n");
> virBufferAdjustIndent(buf, 2);
>
> if (virDomainMemorySourceDefFormat(buf, def) < 0)
Me thinks this too would need some amount of ABI checks wouldn't it?
That is virDomainMemoryDefCheckABIStability for each mem?
With that it would seem this is ACK-able
John
> diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
> index dc949d3c9..87516ca69 100644
> --- a/src/conf/domain_conf.h
> +++ b/src/conf/domain_conf.h
> @@ -2002,6 +2002,8 @@ typedef enum {
> } virDomainMemoryModel;
>
> struct _virDomainMemoryDef {
> + virDomainMemoryAccess access;
> +
> /* source */
> virBitmapPtr sourceNodes;
> unsigned long long pagesize; /* kibibytes */
> diff --git a/tests/qemuxml2argvdata/qemuxml2argv-memory-hotplug-nvdimm-access.xml b/tests/qemuxml2argvdata/qemuxml2argv-memory-hotplug-nvdimm-access.xml
> new file mode 100644
> index 000000000..700e961a6
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/qemuxml2argv-memory-hotplug-nvdimm-access.xml
> @@ -0,0 +1,56 @@
> +<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'>
> + <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
> + </controller>
> + <controller type='usb' index='0'>
> + <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
> + </controller>
> + <controller type='pci' index='0' model='pci-root'/>
> + <input type='mouse' bus='ps2'/>
> + <input type='keyboard' bus='ps2'/>
> + <memballoon model='virtio'>
> + <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
> + </memballoon>
> + <memory model='nvdimm' access='private'>
> + <source>
> + <path>/tmp/nvdimm</path>
> + </source>
> + <target>
> + <size unit='KiB'>523264</size>
> + <node>0</node>
> + </target>
> + <address type='dimm' slot='0'/>
> + </memory>
> + </devices>
> +</domain>
> diff --git a/tests/qemuxml2xmloutdata/qemuxml2xmlout-memory-hotplug-nvdimm-access.xml b/tests/qemuxml2xmloutdata/qemuxml2xmlout-memory-hotplug-nvdimm-access.xml
> new file mode 120000
> index 000000000..4b0496ad5
> --- /dev/null
> +++ b/tests/qemuxml2xmloutdata/qemuxml2xmlout-memory-hotplug-nvdimm-access.xml
> @@ -0,0 +1 @@
> +/home/zippy/work/libvirt/libvirt.git/tests/qemuxml2argvdata/qemuxml2argv-memory-hotplug-nvdimm-access.xml
> \ No newline at end of file
> diff --git a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c
> index e1c341dd5..ef49a79ca 100644
> --- a/tests/qemuxml2xmltest.c
> +++ b/tests/qemuxml2xmltest.c
> @@ -1079,6 +1079,7 @@ mymain(void)
> DO_TEST("memory-hotplug-nonuma", NONE);
> DO_TEST("memory-hotplug-dimm", NONE);
> DO_TEST("memory-hotplug-nvdimm", NONE);
> + DO_TEST("memory-hotplug-nvdimm-access", NONE);
> DO_TEST("net-udp", NONE);
>
> DO_TEST("video-virtio-gpu-device", NONE);
>
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