To: Dan Williams <dan.j.williams@intel.com>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>
References: <1490911959-5146-1-git-send-email-logang@deltatee.com>
 <1491974532.7236.43.camel@kernel.crashing.org>
 <5ac22496-56ec-025d-f153-140001d2a7f9@deltatee.com>
 <1492034124.7236.77.camel@kernel.crashing.org>
 <81888a1e-eb0d-cbbc-dc66-0a09c32e4ea2@deltatee.com>
 <20170413232631.GB24910@bhelgaas-glaptop.roam.corp.google.com>
 <20170414041656.GA30694@obsidianresearch.com>
 <1492169849.25766.3.camel@kernel.crashing.org>
 <630c1c63-ff17-1116-e069-2b8f93e50fa2@deltatee.com>
 <20170414190452.GA15679@bhelgaas-glaptop.roam.corp.google.com>
 <1492207643.25766.18.camel@kernel.crashing.org>
 <bff1e503-95a9-e19f-bfd9-0ff962c63a81@deltatee.com>
 <CAPcyv4jUeKzKDARp6Z35kdPLKnP-M6aF8X5KpOx55CLyjnj4dA@mail.gmail.com>
 <1492311719.25766.37.camel@kernel.crashing.org>
 <CAPcyv4iqnz1B00Q3xG-nGrLXdOyB7ditxmwZyotksLFgUqr+jA@mail.gmail.com>
Cc: Bjorn Helgaas <helgaas@kernel.org>,
        Jason Gunthorpe <jgunthorpe@obsidianresearch.com>,
        Christoph Hellwig <hch@lst.de>, Sagi Grimberg <sagi@grimberg.me>,
        "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Jens Axboe <axboe@kernel.dk>, Steve Wise <swise@opengridcomputing.com>,
        Stephen Bates <sbates@raithlin.com>, Max Gurtovoy <maxg@mellanox.com>,
        Keith Busch <keith.busch@intel.com>, linux-pci@vger.kernel.org,
        linux-scsi <linux-scsi@vger.kernel.org>,
        linux-nvme@lists.infradead.org, linux-rdma@vger.kernel.org,
        linux-nvdimm <linux-nvdimm@ml01.01.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Jerome Glisse <jglisse@redhat.com>
From: Logan Gunthorpe <logang@deltatee.com>
Message-ID: <5e43818e-8c6b-8be8-23ff-b798633d2a73@deltatee.com>
Date: Sun, 16 Apr 2017 10:34:54 -0600
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101
 Icedove/45.6.0
MIME-Version: 1.0
In-Reply-To: <CAPcyv4iqnz1B00Q3xG-nGrLXdOyB7ditxmwZyotksLFgUqr+jA@mail.gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
Subject: Re: [RFC 0/8] Copy Offload with Peer-to-Peer PCI Memory
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 433
Lines: 12


On 16/04/17 09:53 AM, Dan Williams wrote:
> ZONE_DEVICE allows you to redirect via get_dev_pagemap() to retrieve
> context about the physical address in question. I'm thinking you can
> hang bus address translation data off of that structure. This seems
> vaguely similar to what HMM is doing.

Thanks! I didn't realize you had the infrastructure to look up a device
from a pfn/page. That would really come in handy for us.

Logan