Re: [Qemu-devel] [PULL 18/33] vhost-user-scsi: Introduce vhost-user-scsi host device

[Felipe Franciosi]

> On 7 Jun 2017, at 16:47, Peter Maydell <address@hidden> wrote:
> 
> On 7 June 2017 at 16:39, Felipe Franciosi <address@hidden> wrote:
>> 
>>> On 7 Jun 2017, at 16:37, Peter Maydell <address@hidden> wrote:
>>> 
>>> On 7 June 2017 at 16:28, Paolo Bonzini <address@hidden> wrote:
>>>> From: Felipe Franciosi <address@hidden>
>>>> 
>>>> This commit introduces a vhost-user device for SCSI. This is based
>>>> on the existing vhost-scsi implementation, but done over vhost-user
>>>> instead. It also uses a chardev to connect to the backend. Unlike
>>>> vhost-scsi (today), VMs using vhost-user-scsi can be live migrated.
>>>> 
>>>> To use it, start Qemu with a command line equivalent to:
>>>> 
>>>> qemu-system-x86_64 \
>>>>      -chardev socket,id=vus0,path=/tmp/vus.sock \
>>>>      -device vhost-user-scsi-pci,chardev=vus0,bus=pci.0,addr=...
>>>> 
>>>> A separate commit presents a sample application linked with libiscsi to
>>>> provide a backend for vhost-user-scsi.
>>>> 
>>>> Signed-off-by: Felipe Franciosi <address@hidden>
>>>> Message-Id: <address@hidden>
>>>> [Disable migration for now, since it does not support bdrv_drain. - Paolo]
>>> 
>>> I was expecting this to mean a VMStateDescription with a
>>> ".unmigratable = 1" field, but it doesn't seem to have one.
>>> Does it disable migration some other way?
>> 
>> Hi Peter,
>> 
>> vhost-user-scsi supports migration.
> 
> Paolo's change comment in the commit message quoted above
> says it does not, which is what I was remarking on.
> 
> (Your original patches use register_savevm(), which is a function
> that has just gone away. They'd need to use VMStateDescription
> structs instead to support migration.)

Oh thanks for pointing that out, I missed it at the bottom of the commit 
message.

F.

> 
> thanks
> -- PMM