From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: A new direction for vmchannel? Date: Sat, 24 Jan 2009 12:47:16 -0600 Message-ID: <497B6234.3030302@codemonkey.ws> References: <4979D80D.307@us.ibm.com> <20090124171928.GA30108@redhat.com> <497B5546.5060000@codemonkey.ws> <20090124183912.GA7900@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "Daniel P. Berrange" , Dor Laor , Avi Kivity , "qemu-devel@nongnu.org" , Eric Van Hensbergen , kvm-devel , Chris Wright , Eric Van Hensbergen To: Gleb Natapov Return-path: Received: from yw-out-2324.google.com ([74.125.46.29]:18853 "EHLO yw-out-2324.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755185AbZAXSrf (ORCPT ); Sat, 24 Jan 2009 13:47:35 -0500 Received: by yw-out-2324.google.com with SMTP id 9so2358763ywe.1 for ; Sat, 24 Jan 2009 10:47:34 -0800 (PST) In-Reply-To: <20090124183912.GA7900@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Gleb Natapov wrote: > On Sat, Jan 24, 2009 at 11:52:06AM -0600, Anthony Liguori wrote: > >>> For use cases where you are exposing metadata from the host to the guest >>> this would be a very convenient approach indeed. As asked elsewhere in this >>> thread, my main thought would be about how well it suits a application that >>> wants a generic stream based connection between host & guest ? >>> Efficient integration into a poll(2) based event loop would be key to >>> that. >>> >> You mean for a very large number of files (determining which property >> has changed?). >> >> > I think what Daniel means is that for file to have stream semantic it is > not enough to ignore offset on read/write, but poll also should behave > similar to how it behaves with char device fd. With regular files poll > will always report that fd is ready for I/O. > I'm not really sure, but given the 9P protocol, I suspect it would have to. Eric? Regards, Anthony Liguori > -- > Gleb. >