On Fri, Dec 04, 2020 at 12:31:02PM +0300, Andrey Gruzdev wrote: > In this particular implementation the same single migration > thread is responsible for both normal linear dirty page > migration and procesing UFFD page fault events. > > Processing write faults includes reading UFFD file descriptor, > finding respective RAM block and saving faulting page to > the migration stream. After page has been saved, write protection > can be removed. Since asynchronous version of qemu_put_buffer() > is expected to be used to save pages, we also have to flush > migraion stream prior to un-protecting saved memory range. > > Write protection is being removed for any previously protected > memory chunk that has hit the migration stream. That's valid > for pages from linear page scan along with write fault pages. > > Signed-off-by: Andrey Gruzdev <andrey.gruz...@virtuozzo.com>
I still think the ram_save_host_page_pre/post are a bit odd; but I think it's good enough (at least Dave/Juan didn't complain yet, so I guess it's ok). Reviewed-by: Peter Xu <pet...@redhat.com> Thanks, -- Peter Xu
