The virtio-pmem is a virtio variant of NVDIMM and just like
NVDIMM virtio-pmem also allows accessing host pages bypassing
guest page cache. The difference is that if a regular file is
used to back guest's NVDIMM (model='nvdimm') the persistence of
guest writes might not be guaranteed while with virtio-pmem it
is.
To express this new model at domain XML level, I've chosen the
following:
<memory model='virtio-pmem' access='shared'>
<source>
<path>/tmp/virtio_pmem</path>
</source>
<target>
<size unit='KiB'>524288</size>
</target>
<address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
</memory>
Another difference between NVDIMM and virtio-pmem is that while
the former supports NUMA node locality the latter doesn't. And
also, the latter goes onto PCI bus and not into a DIMM module.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
