Subject: Re: [PATCH V7 mlx5-next 08/15] vfio: Define device migration protocol v2

From: Jason Gunthorpe <[email-masked]>
Date: Wed, 16 Feb 2022 08:14:16 -0400

On Wed, Feb 16, 2022 at 03:17:36AM +0000, Tian, Kevin wrote:

> those requests don't rely on vCPUs but still take time to complete
> (thus may break SLA) and are invisible to migration driver (directly
> submitted by the guest thus cannot be estimated). So the only means 
> is for user to wait on a fd with a timeout (based on whatever SLA) and
> if expires then aborts migration (may retry later).

I think I explained in my other email how this can be implemented
today with v2 for STOP_COPY without an event fd.

Such a device might even be able to implement an abort..

Jason