From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: A new direction for vmchannel? Date: Sat, 24 Jan 2009 20:39:12 +0200 Message-ID: <20090124183912.GA7900@redhat.com> References: <4979D80D.307@us.ibm.com> <20090124171928.GA30108@redhat.com> <497B5546.5060000@codemonkey.ws> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "Daniel P. Berrange" , Dor Laor , Avi Kivity , "qemu-devel@nongnu.org" , Eric Van Hensbergen , kvm-devel , Chris Wright To: Anthony Liguori Return-path: Received: from mx2.redhat.com ([66.187.237.31]:53695 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753972AbZAXSlR (ORCPT ); Sat, 24 Jan 2009 13:41:17 -0500 Content-Disposition: inline In-Reply-To: <497B5546.5060000@codemonkey.ws> Sender: kvm-owner@vger.kernel.org List-ID: 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. -- Gleb.