From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
To: Gerd Hoffmann <kraxel@redhat.com>
Cc: Frank Yang <lfy@google.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
Roman Kiryanov <rkir@google.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
virtio-dev@lists.oasis-open.org
Subject: Re: [virtio-dev] Memory sharing device
Date: Thu, 21 Feb 2019 10:03:30 +0000 [thread overview]
Message-ID: <20190221100330.GC2605@work-vm> (raw)
In-Reply-To: <20190221095902.mfa54mu7b4q5524p@sirius.home.kraxel.org>
* Gerd Hoffmann (kraxel@redhat.com) wrote:
> Hi,
>
> > > Note: I think using a pci memory bar (aka host memory mapped into the
> > > guest) as backing storage for dma-bufs isn't going to work.
> >
> > (Not knowing dma-bufs) but could you explain why?
>
> Many places in the linux kernel assume dma-bufs are built out of normal
> ram pages (i.e. something backed by struct page). Which is not the case
> for pci memory bars which are typically ioremapped() (completely or in
> chunks) to access them.
Ah OK, so it's the view from inside the guest that's the problem.
Dave
> cheers,
> Gerd
>
>
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Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
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next prev parent reply other threads:[~2019-02-21 10:03 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-01 20:34 [virtio-dev] Memory sharing device Roman Kiryanov
2019-02-04 5:40 ` Stefan Hajnoczi
2019-02-04 10:13 ` Gerd Hoffmann
2019-02-04 10:18 ` Roman Kiryanov
2019-02-05 7:42 ` Roman Kiryanov
2019-02-05 10:04 ` Dr. David Alan Gilbert
2019-02-05 15:17 ` Frank Yang
2019-02-05 15:21 ` Frank Yang
2019-02-05 21:06 ` Roman Kiryanov
2019-02-06 7:03 ` Gerd Hoffmann
2019-02-06 15:09 ` Frank Yang
2019-02-06 15:11 ` Frank Yang
2019-02-08 7:57 ` Stefan Hajnoczi
2019-02-08 14:46 ` Frank Yang
2019-02-06 20:14 ` Dr. David Alan Gilbert
2019-02-06 20:27 ` Frank Yang
2019-02-07 12:10 ` Cornelia Huck
2019-02-11 14:49 ` Michael S. Tsirkin
2019-02-11 15:14 ` Frank Yang
2019-02-11 15:25 ` Frank Yang
2019-02-12 13:01 ` Michael S. Tsirkin
2019-02-12 13:16 ` Dr. David Alan Gilbert
2019-02-12 13:27 ` Michael S. Tsirkin
2019-02-12 16:17 ` Frank Yang
2019-02-19 7:17 ` Gerd Hoffmann
2019-02-19 15:59 ` Frank Yang
2019-02-20 6:51 ` Gerd Hoffmann
2019-02-20 15:31 ` Frank Yang
2019-02-21 6:55 ` Gerd Hoffmann
2019-02-19 7:12 ` Gerd Hoffmann
2019-02-19 16:02 ` Frank Yang
2019-02-20 7:02 ` Gerd Hoffmann
2019-02-20 15:32 ` Frank Yang
2019-02-21 7:29 ` Gerd Hoffmann
2019-02-21 9:24 ` Dr. David Alan Gilbert
2019-02-21 9:59 ` Gerd Hoffmann
2019-02-21 10:03 ` Dr. David Alan Gilbert [this message]
2019-02-22 6:15 ` Michael S. Tsirkin
2019-02-22 6:42 ` Gerd Hoffmann
2019-02-11 16:57 ` Michael S. Tsirkin
2019-02-12 8:27 ` Roman Kiryanov
2019-02-12 11:25 ` Dr. David Alan Gilbert
2019-02-12 13:47 ` Cornelia Huck
2019-02-12 14:03 ` Michael S. Tsirkin
2019-02-12 15:56 ` Frank Yang
2019-02-12 16:46 ` Dr. David Alan Gilbert
2019-02-12 17:20 ` Frank Yang
2019-02-12 17:26 ` Frank Yang
2019-02-12 19:06 ` Michael S. Tsirkin
2019-02-13 2:50 ` Frank Yang
2019-02-13 4:02 ` Michael S. Tsirkin
2019-02-13 4:19 ` Michael S. Tsirkin
2019-02-13 4:59 ` Frank Yang
2019-02-13 18:18 ` Frank Yang
2019-02-14 7:15 ` Frank Yang
2019-02-22 22:05 ` Michael S. Tsirkin
2019-02-24 21:19 ` Frank Yang
2019-02-13 4:59 ` Frank Yang
2019-02-19 7:54 ` Gerd Hoffmann
2019-02-19 15:54 ` Frank Yang
2019-02-20 3:46 ` Michael S. Tsirkin
2019-02-20 15:24 ` Frank Yang
2019-02-20 19:29 ` Michael S. Tsirkin
2019-02-20 6:25 ` Gerd Hoffmann
2019-02-20 15:30 ` Frank Yang
2019-02-20 15:35 ` Frank Yang
2019-02-21 6:44 ` Gerd Hoffmann
2019-02-12 18:22 ` Michael S. Tsirkin
2019-02-12 19:01 ` Frank Yang
2019-02-12 19:15 ` Michael S. Tsirkin
2019-02-12 20:15 ` Frank Yang
2019-02-12 13:00 ` Michael S. Tsirkin
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