On Tue, Sep 13, 2016 at 05:11:00PM +0300, Michael S. Tsirkin wrote: > On Tue, Sep 13, 2016 at 03:38:38PM +0800, Peter Xu wrote: > > On Mon, Sep 12, 2016 at 03:45:48PM +0300, David Kiarie wrote: > > > > When we say cache here, we are mostly talking about GSI routes in > > > > kernel, right? Since we still don't have other kind of interrupt > > > > caches AFAIK. If so, GSI routes should already been setup even if the > > > > interrupts are not triggered for a single time. So we need to > > > > invalidate them even ir_cache == false. > > > > > > > > > > You're right but I'm not sure how to implement that while avoiding > > > triggering the notifier numerous pointless times during boot. > > > > > > > > > > I think the problem is why cache invalidations during boot will bug > > > > the system. Any clue? > > > > > > > > > > The issue is not too many invalidations. I don't have a very clear idea of > > > how notifiers work but I would assume it spawns a thread or they somehow > > > use a multithreaded approach which would mean triggering the notifier too > > > many times within a very short period many trigger a bunch of issues. > > > > No thread is spawn, we just call the notifier callbacks. > > > > For me it's fairly acceptable that guest sends lots of invalidations > > during boot. That should not lead to any functional issues. If there > > is, then something might be wrong. > > > > I don't know whether mst will like to merge this series even without > > fixing this. Anyway I would still prefer to root cause the issue, or > > at least comment this out in the commit message (or codes somewhere) > > so that we know there is something TBD and might cause misterious > > troubles... > > > > Thanks, > > > > -- peterx > > By now it's minimally intrusive, so yes, I think I'll merge > and we can apply fixes on top incrementally. > E.g. would you like to post the suggested comment as a patch? > > -- > MST
Sorry, in fact I was referring to amd iommu itself, while posting in the int remapping thread. There will be more versions of this one so including a comment there directly is better. -- MST
