On Wed, Jan 21, 2026 at 05:31:32PM +0000, Dr. David Alan Gilbert wrote: > Right that's true for postcopy; but then the only way to load the stream into > that buffer is to load it all at once because of the vmstate problem above. > (and because in the original postcopy we needed the original fd free > for page requests; you might be able to avoid that with multifd now)
Only until now, I recognized that COLO wants to make sure the checkpoint is either completely applied or none applied. So the specialty is COLO does loadvm on top of a running VM, meanwhile COLO may decide to not loadvm afterwards if checkpoint wasn't correctly received. And yes, to cache all device states with current section header definition in the stream, we'll likely need a size. We can still parse the stream as you pointed out previously, but I agree a special SIZE header still makes sense. I suppose that answers my question indeed, thanks! -- Peter Xu
