Re: [PATCH] vdpa/mlx5: set_features should allow reset to zero

On 2/28/2021 1:27 PM, Michael S. Tsirkin wrote:

On Thu, Feb 25, 2021 at 04:56:42PM -0800, Si-Wei Liu wrote:

quoted

Hi Michael,

Are you okay to live without this ioctl for now? I think QEMU is the one
that needs to be fixed and will have to be made legacy guest aware. I think
the kernel can just honor the feature negotiation result done by QEMU and do
as what's told to.Will you agree?

If it's fine, I would proceed to reverting commit fe36cbe067 and related
code in question from the kernel.

Thanks,
-Siwei

Not really, I don't see why that's a good idea.  fe36cbe067 is the code
checking MTU before FEATURES_OK. Spec explicitly allows that.

Alright, but what I meant was this commit
452639a64ad8 ("vdpa: make sure set_features is invoked for legacy").

But I got why you need it in another email (for BE host/guest).

-Siwei