From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [PATCH corrected RFC] uio: add generic driver for PCI 2.3 devices Date: Thu, 09 Jul 2009 15:14:53 -0500 Message-ID: <4A564FBD.3020905@codemonkey.ws> References: <20090709114834.GB26479@redhat.com> <4A5604B3.2090508@codemonkey.ws> <20090709181258.GA4340@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, avi@redhat.com To: "Michael S. Tsirkin" Return-path: Received: from mail-ew0-f226.google.com ([209.85.219.226]:53038 "EHLO mail-ew0-f226.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753644AbZGIUPA (ORCPT ); Thu, 9 Jul 2009 16:15:00 -0400 Received: by ewy26 with SMTP id 26so545037ewy.37 for ; Thu, 09 Jul 2009 13:14:58 -0700 (PDT) In-Reply-To: <20090709181258.GA4340@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Michael S. Tsirkin wrote: > On Thu, Jul 09, 2009 at 09:54:43AM -0500, Anthony Liguori wrote: > >> I know it's not strictly needed for PCI pass through, but it would be >> useful to register the IO regions via UIO. The userspace implementation >> would then use UIO strictly instead of poking the sysfs pci info >> directly. I think that ends up being cleaner. >> > > Hmm, this is good for specific drivers, but for a generic one like qemu, > still need sysfs to figure out the size at least, size of what? > and > we need config accesses which uio does not support now. > And if you use libpci as qemu does now, this interface will likely > go unused. So .. there does not seem to be much point at the moment. > Right, I would expect uio to replace libpci. > My idea is, let's start with a minimal interface, longer term > let's see if we can add config access, mmap and other stuff like eventfd. > Makes sense? > It can certainly grow more features down the road. Regards, Anthony Liguori