Thanks Peter for your quickly response. Is there any workaround to do that？As
you know we must take care the risk of using latest version in product
environment.
Thanks a lot!
> 在 2021年5月13日，22:25，Peter Krempa <pkre...@redhat.com> 写道：
>
> On Thu, May 13, 2021 at 15:25:23 +0800, 梁朝军 wrote:
>> Hi Guy,
>>
>> Does anyone clear how to hot plugin a new vhost-user-blk-pci device to a
>> running VM?
>>
>> Before staring vm , I pass the disk through QEMU command line like below.
>>
>> <qemu:commandline>
>> <qemu:arg value='-object'/>
>> <qemu:arg
>>
>> value='memory-backend-file,id=mem0,size=4G,mem-path=/dev/hugepages,share=on'/>
>> <qemu:arg value='-numa'/>
>> <qemu:arg value='node,memdev=mem0'/>
>> <qemu:arg value='-chardev'/>
>> <qemu:arg
>>
>> value='socket,id=spdk_vhost_blk721ea46a-b306-11eb-a280-525400a98761,path=/var/tmp/vhost.721ea46a-b306-11eb-a280-525400a98761,reconnect=1'/>
>> <qemu:arg value='-device'/>
>> <qemu:arg
>>
>> value='vhost-user-blk-pci,chardev=spdk_vhost_blk721ea46a-b306-11eb-a280-525400a98761,bootindex=1,num-queues=4'/>
>> <qemu:arg value='-chardev'/>
>> <qemu:arg
>>
>> value='socket,id=spdk_vhost_blk2f699c58-d222-4629-9fdc-400c3aadc55e,path=/var/tmp/vhost.2f699c58-d222-4629-9fdc-400c3aadc55e,reconnect=1'/>
>> <qemu:arg value='-device'/>
>> <qemu:arg
>>
>> value='vhost-user-blk-pci,chardev=spdk_vhost_blk2f699c58-d222-4629-9fdc-400c3aadc55e,num-queues=4'/>
>> </qemu:commandline>
>>
>> But I don**t know how to live add a vhost-user-blk-pci device on running
>> VM even with calling attachDevice API now.
>
> You need to use the proper and supported way to use vhost-user-blk:
>
> <disk type='vhostuser' device='disk'>
> <driver name='qemu' type='raw'/>
> <source type='unix' path='/tmp/vhost-blk.sock'>
> <reconnect enabled='yes' timeout='10'/>
> </source>
> <target dev='vdf' bus='virtio'/>
> </disk>
>
> That works also with attachDevice.
>
>
>> OS: redhat 7.4 Libvirt version: 3.4
>
> This is obviously way too old for it. You'll need at least libvirt-7.1
> for that.
>
