On Mon, Jan 16, 2017 at 04:03:22PM +0800, Jason Wang wrote: [...]
> >>>Though I haven't tested with huge pages yet, but this patch should > >>>both solve above issue? I don't know whether you went over the page > >>>walk logic - it should both support huge page, and it will skip > >>>unmapped iova range (at least that's my goal to have this patch). In > >>>that case, looks like this patch is solving the same problem? :) > >>>(though without introducing iova_iterate() interface) > >>> > >>>Please correct me if I misunderstood it. > >>Kind of :) I'm fine with this patch, but just want: > >> > >>- reuse most of the codes in the patch > >>- current memory_region_iommu_replay() logic > >> > >>So what I'm suggesting is a just slight change of API which can let caller > >>decide it need to do with each range of iova. So it could be reused for > >>other things except for replaying. > >> > >>But if you like to keep this patch as is, I don't object it. > >I see. Then I can understand your mean here. I had the same thought > >before, that's why I exposed the vtd_page_walk with a hook. If you > >check the page_walk function comment: > > > >/** > > * vtd_page_walk - walk specific IOVA range, and call the hook > > * > > * @ce: context entry to walk upon > > * @start: IOVA address to start the walk > > * @end: IOVA range end address (start <= addr < end) > > * @hook_fn: the hook that to be called for each detected area > > * @private: private data for the hook function > > */ > > > >So I didn't implement the notification in page_walk at all - but in > >the hook_fn. If any caller that is interested in doing something else > >rather than the notification, we can just simply export the page walk > >interface and provide his/her own "hook_fn", then it'll be triggered > >for each valid page (no matter a huge/small one). > > > >If we can have a more general interface in the future - no matter > >whether we call it iova_iterate() or something else (I'll prefer the > >hooker way to do it, so maybe a common page walker with a hook > >function), we can do it simply (at least for Intel platform) based on > >this vtd_page_walk thing. > > > >Thanks, > > > >-- peterx > > Yes but the problem is hook_fn is only visible inside intel iommu code. Right. Btw, do we have existing issue that can leverage this interface besides replay? -- peterx
