libvirt users - Oct 2014 - Re: is memoryBacking support 'share' and 'mem-path' parameter

Hi,

I want to use this qemu command '-object
memory-backend-file,id=mem,size=2048M,mem-path=/mnt/huge,share=on' with
libvirt but i can't find the 'mem-path' and 'share' in the
documentation.
because the vhost-user backend based on 'share=on' parameter and libvirt
support vhostuser i guess there maybe another way to support this parameter?

this is my xml:
  <cpu>
    <numa>
      <cell id='0' cpus='0' memory='1048576'
memAccess='shared'/>
      <cell id='1' cpus='1' memory='1048576'
memAccess='shared'/>
    </numa>
  </cpu>
 <memoryBacking>
    <hugepages>
      <page size="2" unit="M"
nodeset="0,1"/>
    </hugepages>
    <!--nosharepages/-->
    <!--locked/-->
 </memoryBacking>


    <interface type='vhostuser'>
      <mac address='52:54:00:3b:83:1a'/>
      <source type='unix' path='/path/port1'
mode='client'/>
      <model type='virtio'/>
    </interface>
    <interface type='vhostuser'>
      <mac address='52:54:00:3b:83:1b'/>
      <source type='unix' path='/path/port2'
mode='client'/>
      <model type='virtio'/>
    </interface>


when i create the VM the qemu command is like this without 'share=on'
parameter:
-object
memory-backend-file,prealloc=yes,mem-path=/dev/hugepages/libvirt/qemu,size=1024M,id=ram-node0
-numa node,nodeid=0,cpus=0,memdev=ram-node0
-object
memory-backend-file,prealloc=yes,mem-path=/dev/hugepages/libvirt/qemu,size=1024M,id=ram-node1
-numa node,nodeid=1,cpus=1,memdev=ram-node1

On Wed, Oct 08, 2014 at 10:03:47AM +0800, Linhaifeng
wrote:
>Hi,
>
>I want to use this qemu command '-object
memory-backend-file,id=mem,size=2048M,mem-path=/mnt/huge,share=on' with
libvirt but i can't find the 'mem-path' and 'share' in the
documentation.
>because the vhost-user backend based on 'share=on' parameter and
libvirt support vhostuser i guess there maybe another way to support this
parameter?
>
>this is my xml:
>  <cpu>
>    <numa>
>      <cell id='0' cpus='0' memory='1048576'
memAccess='shared'/>
>      <cell id='1' cpus='1' memory='1048576'
memAccess='shared'/>
this memAccess='shared' is exactly what you need in order for the
share='on' to be appended.  I wonder why it's not there.  What
libvirt
version are you using?
>    </numa>
>  </cpu>
> <memoryBacking>
>    <hugepages>
>      <page size="2" unit="M"
nodeset="0,1"/>
>    </hugepages>
>    <!--nosharepages/-->
>    <!--locked/-->
> </memoryBacking>
>
>
>    <interface type='vhostuser'>
>      <mac address='52:54:00:3b:83:1a'/>
>      <source type='unix' path='/path/port1'
mode='client'/>
>      <model type='virtio'/>
>    </interface>
>    <interface type='vhostuser'>
>      <mac address='52:54:00:3b:83:1b'/>
>      <source type='unix' path='/path/port2'
mode='client'/>
>      <model type='virtio'/>
>    </interface>
>
>
>when i create the VM the qemu command is like this without
'share=on' parameter:
>-object
memory-backend-file,prealloc=yes,mem-path=/dev/hugepages/libvirt/qemu,size=1024M,id=ram-node0
-numa node,nodeid=0,cpus=0,memdev=ram-node0
>-object
memory-backend-file,prealloc=yes,mem-path=/dev/hugepages/libvirt/qemu,size=1024M,id=ram-node1
-numa node,nodeid=1,cpus=1,memdev=ram-node1
>
>_______________________________________________
>libvirt-users mailing list
>libvirt-users@redhat.com
>https://www.redhat.com/mailman/listinfo/libvirt-users

On 2014/10/8 16:57, Martin Kletzander wrote:
> On Wed, Oct 08, 2014 at 10:03:47AM +0800, Linhaifeng wrote:
>> Hi,
>>
>> I want to use this qemu command '-object
memory-backend-file,id=mem,size=2048M,mem-path=/mnt/huge,share=on' with
libvirt but i can't find the 'mem-path' and 'share' in the
documentation.
>> because the vhost-user backend based on 'share=on' parameter
and libvirt support vhostuser i guess there maybe another way to support this
parameter?
>>
>> this is my xml:
>>  <cpu>
>>    <numa>
>>      <cell id='0' cpus='0' memory='1048576'
memAccess='shared'/>
>>      <cell id='1' cpus='1' memory='1048576'
memAccess='shared'/>
> 
> this memAccess='shared' is exactly what you need in order for the
> share='on' to be appended.  I wonder why it's not there.  What
libvirt
> version are you using?
-bash-4.2# virsh --version
1.2.7

> 
>>    </numa>
>>  </cpu>
>> <memoryBacking>
>>    <hugepages>
>>      <page size="2" unit="M"
nodeset="0,1"/>
>>    </hugepages>
>>    <!--nosharepages/-->
>>    <!--locked/-->
>> </memoryBacking>
>>
>>
>>    <interface type='vhostuser'>
>>      <mac address='52:54:00:3b:83:1a'/>
>>      <source type='unix' path='/path/port1'
mode='client'/>
>>      <model type='virtio'/>
>>    </interface>
>>    <interface type='vhostuser'>
>>      <mac address='52:54:00:3b:83:1b'/>
>>      <source type='unix' path='/path/port2'
mode='client'/>
>>      <model type='virtio'/>
>>    </interface>
>>
>>
>> when i create the VM the qemu command is like this without
'share=on' parameter:
>> -object
memory-backend-file,prealloc=yes,mem-path=/dev/hugepages/libvirt/qemu,size=1024M,id=ram-node0
-numa node,nodeid=0,cpus=0,memdev=ram-node0
>> -object
memory-backend-file,prealloc=yes,mem-path=/dev/hugepages/libvirt/qemu,size=1024M,id=ram-node1
-numa node,nodeid=1,cpus=1,memdev=ram-node1
>>
>> _______________________________________________
>> libvirt-users mailing list
>> libvirt-users@redhat.com
>> https://www.redhat.com/mailman/listinfo/libvirt-users