RE: Inter-VM device emulation (call on Mon 20th July 2020)

[Thanos Makatos]

> -----Original Message-----
> From: kvm-owner@vger.kernel.org <kvm-owner@vger.kernel.org> On
> Behalf Of Stefan Hajnoczi
> Sent: 15 July 2020 12:24
> To: Nikos Dragazis <ndragazis@arrikto.com>; Jan Kiszka
> <jan.kiszka@siemens.com>
> Cc: Michael S. Tsirkin <mst@redhat.com>; Thanos Makatos
> <thanos.makatos@nutanix.com>; John G. Johnson
> <john.g.johnson@oracle.com>; Andra-Irina Paraschiv
> <andraprs@amazon.com>; Alexander Graf <graf@amazon.com>; qemu-
> devel@nongnu.org; kvm@vger.kernel.org; Maxime Coquelin
> <maxime.coquelin@redhat.com>; Alex Bennée <alex.bennee@linaro.org>
> Subject: Inter-VM device emulation (call on Mon 20th July 2020)
> 
> Hi,
> Several projects are underway to create an inter-VM device emulation
> interface:
> 
>  * ivshmem v2
>    https://www.mail-archive.com/qemu-devel@nongnu.org/msg706465.html
> 
>    A PCI device that provides shared-memory communication between VMs.
>    This device already exists but is limited in its current form. The
>    "v2" project updates IVSHMEM's capabilities and makes it suitable as
>    a VIRTIO transport.
> 
>    Jan Kiszka is working on this and has posted specs for review.
> 
>  * virtio-vhost-user
>    https://www.mail-archive.com/virtio-dev@lists.oasis-
> open.org/msg06429.html
> 
>    A VIRTIO device that transports the vhost-user protocol. Allows
>    vhost-user device emulation to be implemented by another VM.
> 
>    Nikos Dragazis is working on this with QEMU, DPDK, and VIRTIO patches
>    posted.
> 
>  * VFIO-over-socket
>    https://github.com/tmakatos/qemu/blob/master/docs/devel/vfio-over-
> socket.rst
> 
>    Similar to the vhost-user protocol in spirit but for any PCI device.
>    Uses the Linux VFIO ioctl API as the protocol instead of vhost.
> 
>    It doesn't have a virtio-vhost-user equivalent yet, but the same
>    approach could be applied to VFIO-over-socket too.
> 
>    Thanos Makatos and John G. Johnson are working on this. The draft
>    spec is available.
> 
> Let's have a call to figure out:
> 
> 1. What is unique about these approaches and how do they overlap?
> 2. Can we focus development and code review efforts to get something
>    merged sooner?
> 
> Jan and Nikos: do you have time to join on Monday, 20th of July at 15:00
> UTC?
> https://www.timeanddate.com/worldclock/fixedtime.html?iso=20200720T1
> 500
> 
> Video call URL: https://bluejeans.com/240406010
> 
> It would be nice if Thanos and/or JJ could join the call too. Others
> welcome too (feel free to forward this email)!

Sure!

> 
> Stefan