RE: [virtio-comment] Re: [PATCH v1 3/8] device-context: Define the device context fields for device migration

[Parav Pandit <parav@nvidia.com>]

> From: Michael S. Tsirkin <mst@redhat.com>
> Sent: Wednesday, October 25, 2023 1:55 PM
> 
> On Wed, Oct 25, 2023 at 07:15:24AM +0000, Parav Pandit wrote:
> > Treating all registers equally and synchronizing it in the device is better model
> to not bifurcate the device.
> 
> Glad you like it, though I don't think many hypervisors treat all registers equally.
> Personally I think where does the ideal balance pass depends on specific
> hardware and software. And it is not wise to tie ourselves to specific needs du
> jour.
> 
> So can we please stop arguing about which model is better on this list and
> instead focus on building reusable components that different devices can use as
> they see fit?

Sure. 
There is nothing special done in hypervisor for passthrough member device for virtio command and device specific area.
Going forward for passthrough, nothing special to be done for virtio common+dev specific registers by design.
So, nothing special to be build for it anyway here on the member device.
Hence, I will not debate it again unless it is questioned again.

Other models can anyway do anything suitable with these registers.
Hence, I believe device context as defined now is still reusable as common building block.
For non-passthrough, such hypervisor can simply ignore the fields which it is not interested in.