Re: [libvirt] [PATCH v3 08/17] conf: Introduce @access 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 | 16 ++++++- 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, 96 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 6e89bfe3a..4bc3d92f9 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -1417,7 +1417,7 @@ <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> @@ -7099,7 +7099,7 @@ qemu-kvm -net nic,model=? /dev/null <pre> ... &lt;devices&gt; - &lt;memory model='dimm'&gt; + &lt;memory model='dimm' access='private'&gt; &lt;target&gt; &lt;size unit='KiB'&gt;524287&lt;/size&gt; &lt;node&gt;0&lt;/node&gt; @@ -7138,6 +7138,18 @@ qemu-kvm -net nic,model=? /dev/null </p> </dd> + <dt><code>access</code></dt> + <dd> + <p> + An optional attribute <code>access</code> + (<span class="since">since 3.2.0</span>) that provides + capability to fine tune mapping of the memory on per + module basis. Values are the same as + <a href="#elementsMemoryBacking">Memory Backing</a>: + <code>shared</code> and <code>private</code>. + </p> + </dd> +

From the v2 code review comment/response - can/should we state right