From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [PATCH][RFC] vmchannel a data channel between host and guest. Date: Mon, 13 Oct 2008 13:32:35 -0500 Message-ID: <48F39443.4070203@codemonkey.ws> References: <20081012124534.GK11435@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, Anthony Liguori , Rusty Russell To: Gleb Natapov Return-path: Received: from an-out-0708.google.com ([209.85.132.248]:49706 "EHLO an-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755232AbYJMScm (ORCPT ); Mon, 13 Oct 2008 14:32:42 -0400 Received: by an-out-0708.google.com with SMTP id d40so139612and.103 for ; Mon, 13 Oct 2008 11:32:39 -0700 (PDT) In-Reply-To: <20081012124534.GK11435@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Gleb Natapov wrote: > Hello, > > Sometimes there is a need to pass various bits of information between host > and guest (mostly for management purposes such as host screen resolution > changes or runtime statistics of a guest). To do that we need some way to > pass data between host and guest. Attached patch implements vmchannel that can > be used for this purpose. It is based on virtio infrastructure and > support more then one channel. The vmchannel presents itself as PCI > device to a guest so guest driver is also required. The one for linux is > attached. It uses netlink connector to communicate with userspace. > Essentially, the transport itself ends up looking very much like a network device so the only real design question is what the guest and host interfaces look like. I don't know that a netlink interface is the best interface to userspace. Why not a full blown socket? Perhaps a virtual file system? Having a limit of only 4 links seems like a problem to me too. I think there needs to be a better articulation about why other interfaces cannot be used (like a network device). Is it because of ease of guest configuration? Is it performance? Regards, Anthony Liguori > Comments are welcome. > > -- > Gleb. >