From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
To: Roman Kiryanov <rkir@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
virtio-dev@lists.oasis-open.org, Lingfeng Yang <lfy@google.com>
Subject: Re: [virtio-dev] Memory sharing device
Date: Wed, 6 Feb 2019 20:14:07 +0000 [thread overview]
Message-ID: <20190206201406.GG2670@work-vm> (raw)
In-Reply-To: <CAOGAQeq-djsO=goRsHHz22Zrker8iDqucD30-cEXPt8pVQe1Hg@mail.gmail.com>
* Roman Kiryanov (rkir@google.com) wrote:
> Hi Dave,
>
> > In virtio-fs we have two separate stages:
> > a) A shared arena is setup (and that's what the spec Stefan pointed to is about) -
> > it's statically allocated at device creation and corresponds to a chunk
> > of guest physical address space
>
> We do exactly the same:
> https://android.googlesource.com/platform/external/qemu/+/emu-master-dev/hw/pci/goldfish_address_space.c#659
>
> > b) During operation the guest kernel asks for files to be mapped into
> > part of that arena dynamically, using commands sent over the queue
> > - our queue carries FUSE commands, and we've added two new FUSE
> > commands to perform the map/unmap. They talk in terms of offsets
> > within the shared arena, rather than GPAs.
>
> In our case we have no files to map, only pointers returned from
> OpenGL or Vulkan.
> Do you have the approach to share for this use case?
I should say that the spec I'm talking aobut is my 1st virito spec
change; so take my ideas with a large pinch of salt!
> > How do you transmit the glMapBufferRange command from QEMU driver to
> > host?
>
> In December we did this by passing these bits over our guest-host channel
> (another driver, goldfish_pipe). Frank is currently working on moving
> this into our memory
> mapping device as "something changed in the memory you shared".
>
> Do you this it is possible to have virtio-pipe where we could send
> arbitrary blobs between
> guest and host? We want to move all our drivers into userspace so we
> could share memory
> using the device you are currently working on and this virtio-pipe to
> pass MMIOs and IRQs
> to control our devices to avoid dealing with kernel drivers at all.
It sounds to me like you want something like a virtio-pipe, with
a shared arena (like specified using the spec change I suggested)
but with either a separate queue, or commands in the queue to do the
mapping/unmapping of your GL pointers from your arena.
Dave
> Thank you.
>
> Regards,
> Roman.
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
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next prev parent reply other threads:[~2019-02-06 20:14 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 [this message]
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
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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