Re: [virtio-dev] Memory sharing device

From
Stefan Hajnoczi <>
Date
2019-02-04T05:40:59+00:00
ID
Thread
Re: [virtio-dev] Memory sharing device
On Fri, Feb 01, 2019 at 12:34:07PM -0800, Roman Kiryanov wrote:
> for our purposes we need to access host's memory (e.g. Vulkan buffers,
> but we also considering other things, like running all drivers in
> userspace) directly from a linux guest (Android). I implemented a
> device in QEMU and a linux driver for it:
> 
> https://android.googlesource.com/kernel/goldfish/+/android-goldfish-4.14-dev/drivers/misc/goldfish_address_space.c
> 
> https://android.googlesource.com/platform/external/qemu/+/emu-master-dev/hw/pci/goldfish_address_space.c
> 
> during upstreaming the driver it was suggested that developing a
> virtio spec could be a better approach than inventing our specific
> driver and device.
> 
> Could you please advise how to start?

Hi Roman,
David Gilbert, Gerd Hoffmann, and I have discussed adding shared memory
resources to VIRTIO.  That means memory made available by the device to
the driver instead of the usual other way around.

virtio-gpu needs this and perhaps that use case overlaps with yours too.

virtio-fs and virtio-vhost-user both also need shared memory.

Here is David Gilbert's latest draft spec:
https://lists.oasis-open.org/archives/virtio-comment/201901/msg00000.html

Is this what you were thinking of?

Stefan