Re: [RFC 0/3] iommu/iova: Unsafe locking in find_iova()

[Dmitry Safonov <dima@arista.com>]

On Fri, 2018-07-06 at 17:13 +0200, Joerg Roedel wrote:
> On Fri, Jul 06, 2018 at 03:10:47PM +0100, Dmitry Safonov wrote:
> > Yes, as far as I can see, there are code-paths which may try to
> > handle
> > it at the same time:
> > o memory notifiers for hot-unplug (intel-iommu.c)
> > o drivers unloading calls free_iova(), which in the result calls
> >   find_iova()
> > o I see at least one driver that frees iova during it's normal work
> >   too: scif_rma.c:scif_free_window_offset()
> 
> Yeah, but the IOVAs freed in the memory notifiers are just the ones
> for
> the direct-mapped RMRR regions requested by firmware, not the IOVAs
> allocated by any driver, so I think this shouldn't be a problem.

Ok, than drop it, please.
I thought that safer API + nice diffstat can justify the change, but
whatever %)

-- 
Thanks,
             Dmitry