[libvirt] [PATCH v2 05/14] conf: Introduce @access to <memory/>

Michal Privoznik posted 14 patches 8 years, 11 months ago
There is a newer version of this series
[libvirt] [PATCH v2 05/14] conf: Introduce @access to <memory/>
Posted by Michal Privoznik 8 years, 11 months ago
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@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>
 ...
 &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;
@@ -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>
+          (<span class="since">Since 3.1.0</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 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)
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);
-- 
2.11.0

--
libvir-list mailing list
libvir-list@redhat.com
https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] [PATCH v2 05/14] conf: Introduce @access to <memory/>
Posted by John Ferlan 8 years, 11 months ago

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@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>
>  ...
>  &lt;devices&gt;
> -  &lt;memory model='dimm'&gt;
> +  &lt;memory model='dimm' access='private'&gt;

Hmmm... this type of change almost makes it seem as though access will
be required or written out always now.

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

--
libvir-list mailing list
libvir-list@redhat.com
https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] [PATCH v2 05/14] conf: Introduce @access to <memory/>
Posted by Michal Privoznik 8 years, 11 months ago
On 03/07/2017 05:23 PM, John Ferlan wrote:
> 
> 
> 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@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>
>>  ...
>>  &lt;devices&gt;
>> -  &lt;memory model='dimm'&gt;
>> +  &lt;memory model='dimm' access='private'&gt;
> 
> Hmmm... this type of change almost makes it seem as though access will
> be required or written out always now.
> 
>>      &lt;target&gt;
>>        &lt;size unit='KiB'&gt;524287&lt;/size&gt;
>>        &lt;node&gt;0&lt;/node&gt;
>> @@ -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 &lt;cell/&gt;:
>> +          <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?

I don't think so. 'access' is an attribute of backend, not frontend.
Therefore guest has no idea what mode is particular NVDIMM in. Thus it's
not part of ABI.

Michal

--
libvir-list mailing list
libvir-list@redhat.com
https://www.redhat.com/mailman/listinfo/libvir-list