From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: [PATCH] AF_VMCHANNEL address family for guest<->host communication. Date: Tue, 16 Dec 2008 08:57:27 +0200 Message-ID: <20081216065727.GD13794__46702.3243000314$1229410882$gmane$org@redhat.com> References: <4946717F.2090809@codemonkey.ws> <20081215.114315.165733593.davem@davemloft.net> <4946C1AA.4080404@codemonkey.ws> <20081215.142918.190909950.davem@davemloft.net> <4946E1BA.80206@codemonkey.ws> <20081215234511.GA24579@ioremap.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20081215234511.GA24579@ioremap.net> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Evgeniy Polyakov Cc: netdev@vger.kernel.org, kvm@vger.kernel.org, David Miller , Anthony Liguori , virtualization@lists.linux-foundation.org List-Id: virtualization@lists.linuxfoundation.org On Tue, Dec 16, 2008 at 02:45:11AM +0300, Evgeniy Polyakov wrote: > Hi Anthony. > > On Mon, Dec 15, 2008 at 05:01:14PM -0600, Anthony Liguori (anthony@codemonkey.ws) wrote: > > Yes, and I went down the road of using a dedicated network device and > > using raw ethernet as the protocol. The thing that killed that was the > > fact that it's not reliable. You need something like TCP to add > > reliability. > > > > But that's a lot of work and a bit backwards. Use a unreliable > > transport but use TCP on top of it to get reliability. Our link > > (virtio) is inherently reliable so why not just expose a reliable > > interface to userspace? > > I removed original mail and did not check archive, but doesn't rx/tx > queues of the virtio device have limited size? I do hope they have, > which means that either your network drops packets or blocks. > It blocks. > Another approach is to implement that virtio backend with netlink based > userspace interface (like using connector or genetlink). This does not > differ too much from what you have with special socket family, but at > least it does not duplicate existing functionality of > userspace-kernelspace communications. > I implemented vmchannel using connector initially (the downside is that message can be dropped). Is this more expectable for upstream? The implementation was 300 lines of code. -- Gleb.