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

From: "Michael S. Tsirkin" <[email-masked]>
Date: Sun, 28 Feb 2021 16:34:53 -0500

On Wed, Feb 24, 2021 at 10:24:41AM -0800, Si-Wei Liu wrote:
> > Detecting it isn't enough though, we will need a new ioctl to notify
> > the kernel that it's a legacy guest. Ugh :(
> Well, although I think adding an ioctl is doable, may I know what the use
> case there will be for kernel to leverage such info directly? Is there a
> case QEMU can't do with dedicate ioctls later if there's indeed
> differentiation (legacy v.s. modern) needed?

BTW a good API could be

#define VHOST_SET_ENDIAN _IOW(VHOST_VIRTIO, ?, int)
#define VHOST_GET_ENDIAN _IOW(VHOST_VIRTIO, ?, int)

we did it per vring but maybe that was a mistake ...

-- 
MST