Re: [virtio-dev] Memory sharing device

[Gerd Hoffmann <kraxel@redhat.com>]

  Hi,

> slots by doing so. So for Vulkan, we rely on having one large host visible
> region on the host that is a single region of host shared memory. That, is
> then sub-allocated for the guest. So there is no Vulkan host pointer that

Yes, sub-allocating will be needed for reasonable performance.

> In general though, this means that the ideal usage of host pointers would
> be to set a few regions up front for certain purposes, then share that out
> amongst other device contexts. This also facilitates sharing the memory
> between guest processes, which is useful for implementing things like
> compositors.

Guest processes in the same VM or in different VMs?

> This also features heavily for our "virtio userspace" thing.
> Since this is a common pattern, should this sharing concept be standardized
> somehow? I.e., should there be a standard way to send Shmid/offset/size to
> other devices, or have that be a standard struct in the hypervisor?

Same question: other devices of the same VM?

cheers,
  Gerd