From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] ioeventfd: Introduce KVM_IOEVENTFD_FLAG_PIPE Date: Mon, 04 Jul 2011 17:45:35 +0300 Message-ID: <4E11D20F.9020509@redhat.com> References: <1309712689-4290-1-git-send-email-levinsasha928@gmail.com> <4E10A3E6.1070606@redhat.com> <1309715091.4117.16.camel@sasha> <4E1195A1.10103@redhat.com> <1309790307.4117.25.camel@sasha> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, Ingo Molnar , Marcelo Tosatti , "Michael S. Tsirkin" , Pekka Enberg To: Sasha Levin Return-path: Received: from mx1.redhat.com ([209.132.183.28]:18245 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753974Ab1GDOpq (ORCPT ); Mon, 4 Jul 2011 10:45:46 -0400 In-Reply-To: <1309790307.4117.25.camel@sasha> Sender: kvm-owner@vger.kernel.org List-ID: On 07/04/2011 05:38 PM, Sasha Levin wrote: > > > > In general incremental development is great, but I don't want to > > fragment the ABI. I'd like to be able to forward an entire PCI BAR over > > a pipe. That means sending the address/data/length tuple, and both read > > and write support. > > Would this mean that for sockets we want to remove the 8 byte limit? Yes. Register a range and support all sizes. Perhaps it merits a separate ioctl. > What about eventfds? We can remove the limit there and assume that if > the user asked for more than 8 bytes he knows what he's doing? I can't really see that as useful. eventfds destroy information; without datamatch, you have no idea what value was written. Even with datamatch, you have no idea how many times it was written. With a range, you also have no idea which address was written. It's pretty meaningless. -- error compiling committee.c: too many arguments to function