From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Date: Thu, 19 Mar 2020 00:28:49 +0000 Subject: Re: ensure device private pages have an owner v2 Message-Id: <20200319002849.GG20941@ziepe.ca> List-Id: References: <20200316193216.920734-1-hch@lst.de> In-Reply-To: <20200316193216.920734-1-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Christoph Hellwig Cc: Dan Williams , Bharata B Rao , Christian =?utf-8?B?S8O2bmln?= , Ben Skeggs , Jerome Glisse , kvm-ppc@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org, linux-mm@kvack.org On Mon, Mar 16, 2020 at 08:32:12PM +0100, Christoph Hellwig wrote: > When acting on device private mappings a driver needs to know if the > device (or other entity in case of kvmppc) actually owns this private > mapping. This series adds an owner field and converts the migrate_vma > code over to check it. I looked into doing the same for > hmm_range_fault, but as far as I can tell that code has never been > wired up to actually work for device private memory, so instead of > trying to fix some unused code the second patch just remove the code. > We can add it back once we have a working and fully tested code, and > then should pass the expected owner in the hmm_range structure. > > Changes since v1: > - split out the pgmap->owner addition into a separate patch > - check pgmap->owner is set for device private mappings > - rename the dev_private_owner field in struct migrate_vma to src_owner > - refuse to migrate private pages if src_owner is not set > - keep the non-fault device private handling in hmm_range_fault I'm happy enough to take this, did you have plans for a v3? Thanks, Jason