From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-5424-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis.ws5.connectedcommunity.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 32498985E0D for ; Wed, 13 Feb 2019 04:19:11 +0000 (UTC) Date: Tue, 12 Feb 2019 23:19:01 -0500 From: "Michael S. Tsirkin" Message-ID: <20190212231458-mutt-send-email-mst@kernel.org> References: <20190212112547.GC2715@work-vm> <20190212144741.60083682.cohuck@redhat.com> <20190212090121-mutt-send-email-mst@kernel.org> <20190212164626.GG2715@work-vm> <20190212135924-mutt-send-email-mst@kernel.org> <20190212221738-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190212221738-mutt-send-email-mst@kernel.org> Subject: Re: [virtio-dev] Memory sharing device To: Frank Yang Cc: "Dr. David Alan Gilbert" , Cornelia Huck , Roman Kiryanov , Gerd Hoffmann , Stefan Hajnoczi , virtio-dev@lists.oasis-open.org, Greg Hartman List-ID: On Tue, Feb 12, 2019 at 11:02:19PM -0500, Michael S. Tsirkin wrote: > On Tue, Feb 12, 2019 at 06:50:29PM -0800, Frank Yang wrote: > > > > > > On Tue, Feb 12, 2019 at 11:06 AM Michael S. Tsirkin wrote: > > > > On Tue, Feb 12, 2019 at 09:26:10AM -0800, Frank Yang wrote: > > > BTW, the other unique aspect is that the ping messages allow a _host_ > > pointer > > > to serve as the lump of shared memory; > > > then there is no need to track buffers in the guest kernel and the device > > > implementation can perform specialize buffer space management. > > > Because it is also host pointer shared memory, it is also physically > > contiguous > > > and there is no scatterlist needed to process the traffic. > > > > Yes at the moment virtio descriptors all pass addresses guest to host. > > > > Ability to reverse that was part of the vhost-pci proposal a while ago. > > BTW that also at least originally had ability to tunnel > > multiple devices over a single connection. > > > > > > > > Can there be a similar proposal for virtio-pci without vhsot? > > > > There was nothing wrong with the proposals I think, they > > just had to be polished a bit before making it into the spec. > > And that runneling was dropped but I think it can be brought back > > if desired, we just didn't see a use for it. > > > > > > Thinking about it more, I think vhost-pci might be too much for us due to the > > vhost requirement (sockets and IPC while we desire a highly process local > > solution) > > I agree because the patches try to document a bunch of stuff. > But I really just mean taking the host/guest interface > part from there. Tomorrow I'll try to write up a little bit more about the vhost pci ideas. The patches on list go deep into envisioned implementation detail within qemu instead of the actual host/guest interface. You should then be able to figure out they are relevant for you. -- MST --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org