From: Logan Gunthorpe <logang@deltatee.com>
To: Christoph Hellwig <hch@lst.de>, Jerome Glisse <jglisse@redhat.com>
Cc: "Koenig, Christian" <Christian.Koenig@amd.com>,
Jason Gunthorpe <jgg@mellanox.com>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J . Wysocki" <rafael@kernel.org>,
Bjorn Helgaas <bhelgaas@google.com>,
"Kuehling, Felix" <Felix.Kuehling@amd.com>,
"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
"dri-devel@lists.freedesktop.org"
<dri-devel@lists.freedesktop.org>,
Marek Szyprowski <m.szyprowski@samsung.com>,
Robin Murphy <robin.murphy@arm.com>,
Joerg Roedel <jroedel@suse.de>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>
Subject: Re: [RFC PATCH 3/5] mm/vma: add support for peer to peer to device vma
Date: Wed, 30 Jan 2019 10:32:03 -0700 [thread overview]
Message-ID: <39edda88-acd8-c8ec-a6a5-64898006b69f@deltatee.com> (raw)
In-Reply-To: <20190130172653.GA6707@lst.de>
On 2019-01-30 10:26 a.m., Christoph Hellwig wrote:
> On Wed, Jan 30, 2019 at 10:55:43AM -0500, Jerome Glisse wrote:
>> Even outside GPU driver, device driver like RDMA just want to share their
>> doorbell to other device and they do not want to see those doorbell page
>> use in direct I/O or anything similar AFAICT.
>
> At least Mellanox HCA support and inline data feature where you
> can copy data directly into the BAR. For something like a usrspace
> NVMe target it might be very useful to do direct I/O straight into
> the BAR for that.
Yup, these are things we definitely want to be able to do, and have done
with hacky garbage code: Direct I/O from NVMe to P2P BAR, then we could
Direct I/O to another drive or map it as an MR and send it over an RNIC.
We'd definitely like to move in that direction. And a world where such
userspace mappings are gimpped by the fact that they are only some
special feature of userspace VMAs that can only be used in specialized
userspace interfaces is not useful to us.
Logan
next prev parent reply other threads:[~2019-01-30 17:32 UTC|newest]
Thread overview: 95+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-29 17:47 [RFC PATCH 0/5] Device peer to peer (p2p) through vma jglisse
2019-01-29 17:47 ` [RFC PATCH 1/5] pci/p2p: add a function to test peer to peer capability jglisse
2019-01-29 18:24 ` Logan Gunthorpe
2019-01-29 19:44 ` Greg Kroah-Hartman
2019-01-29 19:53 ` Jerome Glisse
2019-01-29 20:44 ` Logan Gunthorpe
2019-01-29 21:00 ` Jerome Glisse
2019-01-29 19:56 ` Alex Deucher
2019-01-29 20:00 ` Jerome Glisse
2019-01-29 20:24 ` Logan Gunthorpe
2019-01-29 21:28 ` Alex Deucher
2019-01-30 10:25 ` Christian König
2019-01-29 17:47 ` [RFC PATCH 2/5] drivers/base: " jglisse
2019-01-29 18:26 ` Logan Gunthorpe
2019-01-29 19:54 ` Jerome Glisse
2019-01-29 19:46 ` Greg Kroah-Hartman
2019-01-29 19:56 ` Jerome Glisse
2019-01-29 17:47 ` [RFC PATCH 3/5] mm/vma: add support for peer to peer to device vma jglisse
2019-01-29 18:36 ` Logan Gunthorpe
2019-01-29 19:11 ` Jerome Glisse
2019-01-29 19:24 ` Logan Gunthorpe
2019-01-29 19:44 ` Jerome Glisse
2019-01-29 20:43 ` Logan Gunthorpe
2019-01-30 7:52 ` Christoph Hellwig
2019-01-29 19:32 ` Jason Gunthorpe
2019-01-29 19:50 ` Jerome Glisse
2019-01-29 20:24 ` Jason Gunthorpe
2019-01-29 20:44 ` Jerome Glisse
2019-01-29 23:02 ` Jason Gunthorpe
2019-01-30 0:08 ` Jerome Glisse
2019-01-30 4:30 ` Jason Gunthorpe
2019-01-30 15:43 ` Jerome Glisse
2019-01-29 20:39 ` Logan Gunthorpe
2019-01-29 20:57 ` Jerome Glisse
2019-01-29 21:30 ` Logan Gunthorpe
2019-01-29 21:50 ` Jerome Glisse
2019-01-29 22:58 ` Logan Gunthorpe
2019-01-29 23:47 ` Jerome Glisse
2019-01-30 1:17 ` Logan Gunthorpe
2019-01-30 2:48 ` Jerome Glisse
2019-01-30 4:18 ` Jason Gunthorpe
2019-01-30 8:00 ` Christoph Hellwig
2019-01-30 15:49 ` Jerome Glisse
2019-01-30 19:06 ` Jason Gunthorpe
2019-01-30 19:45 ` Logan Gunthorpe
2019-01-30 19:59 ` Jason Gunthorpe
2019-01-30 21:01 ` Logan Gunthorpe
2019-01-30 21:50 ` Jason Gunthorpe
2019-01-30 22:52 ` Logan Gunthorpe
2019-01-30 23:30 ` Jason Gunthorpe
2019-01-31 8:13 ` Christoph Hellwig
2019-01-31 15:37 ` Jerome Glisse
2019-01-31 19:02 ` Jason Gunthorpe
2019-01-31 19:19 ` Logan Gunthorpe
2019-01-31 19:54 ` Jason Gunthorpe
2019-01-31 19:35 ` Jerome Glisse
2019-01-31 19:44 ` Logan Gunthorpe
2019-01-31 19:58 ` Jason Gunthorpe
2019-01-30 17:17 ` Logan Gunthorpe
2019-01-30 18:56 ` Jason Gunthorpe
2019-01-30 19:22 ` Jerome Glisse
2019-01-30 19:38 ` Jason Gunthorpe
2019-01-30 20:00 ` Logan Gunthorpe
2019-01-30 20:11 ` Jason Gunthorpe
2019-01-30 20:43 ` Jerome Glisse
2019-01-30 20:50 ` Jason Gunthorpe
2019-01-30 21:45 ` Jerome Glisse
2019-01-30 21:56 ` Jason Gunthorpe
2019-01-30 22:30 ` Jerome Glisse
2019-01-30 22:33 ` Jason Gunthorpe
2019-01-30 22:47 ` Jerome Glisse
2019-01-30 22:51 ` Jason Gunthorpe
2019-01-30 22:58 ` Jerome Glisse
2019-01-30 19:52 ` Logan Gunthorpe
2019-01-30 20:35 ` Jerome Glisse
2019-01-29 20:58 ` Jason Gunthorpe
2019-01-30 8:02 ` Christoph Hellwig
2019-01-30 10:33 ` Koenig, Christian
2019-01-30 15:55 ` Jerome Glisse
2019-01-30 17:26 ` Christoph Hellwig
2019-01-30 17:32 ` Logan Gunthorpe [this message]
2019-01-30 17:39 ` Jason Gunthorpe
2019-01-30 18:05 ` Jerome Glisse
2019-01-30 17:44 ` Jason Gunthorpe
2019-01-30 18:13 ` Logan Gunthorpe
2019-01-30 18:50 ` Jerome Glisse
2019-01-31 8:02 ` Christoph Hellwig
2019-01-31 15:03 ` Jerome Glisse
2019-01-30 19:19 ` Jason Gunthorpe
2019-01-30 19:48 ` Logan Gunthorpe
2019-01-30 20:44 ` Jason Gunthorpe
2019-01-31 8:05 ` Christoph Hellwig
2019-01-31 15:11 ` Jerome Glisse
2019-01-29 17:47 ` [RFC PATCH 4/5] mm/hmm: add support for peer to peer to HMM device memory jglisse
2019-01-29 17:47 ` [RFC PATCH 5/5] mm/hmm: add support for peer to peer to special device vma jglisse
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=39edda88-acd8-c8ec-a6a5-64898006b69f@deltatee.com \
--to=logang@deltatee.com \
--cc=Christian.Koenig@amd.com \
--cc=Felix.Kuehling@amd.com \
--cc=bhelgaas@google.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=gregkh@linuxfoundation.org \
--cc=hch@lst.de \
--cc=iommu@lists.linux-foundation.org \
--cc=jgg@mellanox.com \
--cc=jglisse@redhat.com \
--cc=jroedel@suse.de \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-pci@vger.kernel.org \
--cc=m.szyprowski@samsung.com \
--cc=rafael@kernel.org \
--cc=robin.murphy@arm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox