From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH corrected RFC] uio: add generic driver for PCI 2.3 devices Date: Thu, 9 Jul 2009 23:21:45 +0300 Message-ID: <20090709202145.GA4955@redhat.com> References: <20090709114834.GB26479@redhat.com> <4A5604B3.2090508@codemonkey.ws> <20090709181258.GA4340@redhat.com> <4A564FBD.3020905@codemonkey.ws> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org, avi@redhat.com To: Anthony Liguori Return-path: Received: from mx2.redhat.com ([66.187.237.31]:39478 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756636AbZGIUWa (ORCPT ); Thu, 9 Jul 2009 16:22:30 -0400 Content-Disposition: inline In-Reply-To: <4A564FBD.3020905@codemonkey.ws> Sender: kvm-owner@vger.kernel.org List-ID: On Thu, Jul 09, 2009 at 03:14:53PM -0500, Anthony Liguori wrote: > 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? memory region which you mmap. >> 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. OK, I'll try to get it included as is, then grow it. -- MST