Re: [Qemu-devel] [PATCH RFC 1/2] virtio-blk: add DISCARD and WRITE ZEROES features

[Stefano Garzarella]

On Thu, Jan 24, 2019 at 6:55 PM Dr. David Alan Gilbert
<address@hidden> wrote:
>
> * Stefano Garzarella (address@hidden) wrote:
> > This patch adds the support of DISCARD and WRITE ZEROES commands,
> > that have been introduced in the virtio-blk protocol to have
> > better performance when using SSD backend.
> >
> > Signed-off-by: Stefano Garzarella <address@hidden>
>
> Hi,
>   Do you need to make those features machine-type dependent
> so that a VM started on a nice new qemu with this feature doesn't
> get confused when live migrated back to an older version?
>

Hi Dave,
oh, thanks! I think the answer is absolutely yes :)
I'll fix it!

Another doubt that I have now is that I need to flush the
MultiReqBuffer before submitting DISCARD or WRITE ZEROES commands.

Thanks,
Stefano