Re: [virtio-comment] [PATCH v1 1/8] admin: Add theory of operation for device migration

["Zhu, Lingshan" <lingshan.zhu@intel.com>]

On 10/13/2023 7:49 PM, Michael S. Tsirkin wrote:
> On Fri, Oct 13, 2023 at 11:28:50AM +0000, Parav Pandit wrote:
> > > > > > > inflight descriptor tracking will be implemented by Eugenio in V2.
> > > > > > When we have near complete proposal from two device vendors, you
> > > > > > want to push something to unknown future without reviewing the work;
> > > > > > does not
> > > > > make sense.
> > > > > Didn't I ever provide feedback to you? Really?
> > > > No. I didnât see why you need to post a new patch for dirty page tracking,
> > > when it is already present in this series.
> > This is plain ignorance and shows non_cooperative mode of working in technical committee.
>
> I personally think it's fine to have multiple proposals on the table.
> For example, current Zhu Lingshan's patch is clearly incomplete without
> memory change tracking.
> Why shouldn't he post a patchset demonstrating
> how that is supposed to work in his view?
> I am personally interested in seeing how is that
> supposed to work   - his latest proposal relies on migrating by
> trapping memory accesses but DMA can't be trapped like this generally.
Yes, dirty page tracking will be included in V2, the config space bar/cap
look like the draft I present before, and the dirty page bitmap placed in
host memory that isolated by the PASID, device DMA writing to the bitmap,
and that can avoid RMW process.

Let me sycn with Eugenio, see whether we can include his "inflight 
descriptors tracking"
in this V2.

Thanks
> In the end we want something addressing all use cases though
> and integrating reasonably well with existing ecosystem.