Re: [PATCH 2/2] Allow VIRTIO_F_IN_ORDER to be negotiated for vdpa devices

[Stefano Garzarella <sgarzare@redhat.com>]

On Thu, Feb 17, 2022 at 02:32:48AM -0500, Michael S. Tsirkin wrote:
>On Tue, Feb 15, 2022 at 12:52:31PM +0530, Gautam Dawar wrote:
>> This patch adds the ability to negotiate VIRTIO_F_IN_ORDER bit
>> for vhost-vdpa backend when the underlying device supports this
>> feature.
>> This would aid in reaping performance benefits with HW devices
>> that implement this feature. At the same time, it shouldn't have
>> any negative impact as vhost-vdpa backend doesn't involve any
>> userspace virtqueue operations.
>>
>> Signed-off-by: Gautam Dawar <gdawar@xilinx.com>
>
>Having features that hardware implements but qemu does not
>means we can't migrate between them.
>So I'd rather see a userspace implementation.

FYI Jason proposed to support VIRTIO_F_IN_ORDER in QEMU/Linux as an idea 
for the next GSoC/Outreachy. I offered to mentor and prepared a project 
description [1], if anyone else is interested, it would be great to have 
a co-mentor :-)

Thanks,
Stefano

[1] https://lists.gnu.org/archive/html/qemu-devel/2022-02/msg04032.html