Re: [PATCH 0/4] memory: Add memory_region_msync() & make NVMe emulated device generic

[Philippe Mathieu-Daudé]

On Fri, May 8, 2020 at 5:34 PM Philippe Mathieu-Daudé <address@hidden> wrote:
>
> On 5/8/20 5:33 PM, Paolo Bonzini wrote:
> > On 08/05/20 17:20, Beata Michalska wrote:
> >>>
> >>> mr->dirty_log_mask tells if dirty tracking has been enabled, not if the
> >>> page is dirty.  It would always be true during live migration and when
> >>> running on TCG, but otherwise it would always be false.
> >>>
> >>> Beata, can you explain what you had in mind? :)
> >>>
> >> It has been a while ... , but the intention there was to skip the sync
> >> if there is nothing to be synced in the first place - so for performance
> >> reasons. I honestly do not recall why I went for the dirty_log_mask,
> >> as that seems not  to be the right choice .
> >
> > You probably wanted to look at the dirty bitmap, but you would have to
> > define a new bitmap rather than looking at dirty_log_mask.
> >
> > But that's cool, because it means that we can just remove it!  Thanks,
>
> So I understand I can simply rename memory_region_writeback ->
> memory_region_msync in patch #2.

(removing the mr->dirty_log_mask).