From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH v3 1/1] Shared memory uio_pci driver Date: Sun, 28 Mar 2010 12:45:02 +0300 Message-ID: <4BAF251E.50609@redhat.com> References: <1269497376-21903-1-git-send-email-cam@cs.ualberta.ca> <4BAB30EE.4020509@redhat.com> <8286e4ee1003250924q7cca5e71u8b8b7c6d8b785eb8@mail.gmail.com> <4BAB90BB.5030401@redhat.com> <8286e4ee1003260914u5e6ceee2pf0c00590de182fb6@mail.gmail.com> <4BAE44F2.20801@redhat.com> <20100328074754.GA21749@redhat.com> <4BAF0D03.7060300@redhat.com> <20100328094006.GB21749@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Cam Macdonell , kvm@vger.kernel.org, qemu-devel@nongnu.org To: "Michael S. Tsirkin" Return-path: Received: from mx1.redhat.com ([209.132.183.28]:32548 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752697Ab0C1JpF (ORCPT ); Sun, 28 Mar 2010 05:45:05 -0400 In-Reply-To: <20100328094006.GB21749@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 03/28/2010 12:40 PM, Michael S. Tsirkin wrote: >>> uio accepts 32 bit writes to the char device file. We can encode >>> the fd number there, and use the high bit to signal assign/deassign. >>> >>> >> Ugh. Very unexpandable. >> > It currently fails on any non-4 byte write. > So if we need more bits in the future we can always teach it > about e.g. 8 byte writes. > > Do you think it's worth it doing it now already, and using > 8 byte writes for msi mapping? > Aren't ioctls a lot simpler? Multiplexing multiple functions on write()s is just ioctls done uglier. -- error compiling committee.c: too many arguments to function