From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NeaNG-0003LJ-1R for qemu-devel@nongnu.org; Mon, 08 Feb 2010 15:38:26 -0500 Received: from [199.232.76.173] (port=38036 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NeaNF-0003L6-KM for qemu-devel@nongnu.org; Mon, 08 Feb 2010 15:38:25 -0500 Received: from Debian-exim by monty-python.gnu.org with spam-scanned (Exim 4.60) (envelope-from ) id 1NeaND-0005jJ-6X for qemu-devel@nongnu.org; Mon, 08 Feb 2010 15:38:25 -0500 Received: from mx20.gnu.org ([199.232.41.8]:6261) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1NeaNC-0005bp-8o for qemu-devel@nongnu.org; Mon, 08 Feb 2010 15:38:22 -0500 Received: from mx1.redhat.com ([209.132.183.28]) by mx20.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NeaNA-0007pf-DV for qemu-devel@nongnu.org; Mon, 08 Feb 2010 15:38:20 -0500 Date: Mon, 8 Feb 2010 22:34:59 +0200 From: "Michael S. Tsirkin" Subject: Re: [Qemu-devel] Re: [PATCH] pci: initialize header type register. Message-ID: <20100208203459.GC17088@redhat.com> References: <20100208162753.GA28230@redhat.com> <4B7048E9.6000706@redhat.com> <20100208173204.GA10716@redhat.com> <4B704BE5.9010205@redhat.com> <20100208173741.GB10716@redhat.com> <20100208182624.GD10716@redhat.com> <4B706C4E.2010508@redhat.com> <20100208201919.GA17088@redhat.com> <4B7074DA.10408@codemonkey.ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4B7074DA.10408@codemonkey.ws> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: Blue Swirl , Isaku Yamahata , Gerd Hoffmann , qemu-devel@nongnu.org On Mon, Feb 08, 2010 at 02:32:26PM -0600, Anthony Liguori wrote: > On 02/08/2010 02:19 PM, Michael S. Tsirkin wrote: >> On Mon, Feb 08, 2010 at 08:55:58PM +0100, Gerd Hoffmann wrote: >> >>> Hi, >>> >>> >>>> This still means we have two copies of same data >>>> and need to maintain code that keeps them in sync, >>>> even if that is called just at init time. >>>> >>> No. There is nothing to keep in sync. And there is no extra copy of data. >>> >>> Today you have pci_set_*() calls somewhere in PCIDeviceInfo->init(). >>> I'd like to see them replaced with PCIDeviceInfo->$field + setup in >>> common code. The information that device $foo has vendor id 42 and >>> device id 4711 (and other properties) just moves from code to data. >>> >> We still need it in config array which is read by guest. >> So that is two places. >> > > There's no reason that we couldn't make the config space read like all > of the other spaces we support. IOW, instead of using an array to store > the data, store each element in a structure, and have a big switch(). > > I'm not sure one's better than the other though TBH. Yea. So the solution that needs less code is better. > I think just universally moving to a set of accessors that took a > PCIDevice as an argument in the form of pci_device_set_vendor() would be > a big improvement. > > Regards, > > Anthony Liguori Not sure it's such a *big* improvement, but I won't object to that. -- MST