From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=59879 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PARaZ-0004SY-TU for qemu-devel@nongnu.org; Mon, 25 Oct 2010 14:16:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PARaB-0004sI-Cr for qemu-devel@nongnu.org; Mon, 25 Oct 2010 14:15:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:1026) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PARaB-0004s8-3x for qemu-devel@nongnu.org; Mon, 25 Oct 2010 14:15:43 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o9PIFg1M032670 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 25 Oct 2010 14:15:42 -0400 Date: Mon, 25 Oct 2010 20:15:40 +0200 From: Gleb Natapov Subject: Re: [Qemu-devel] [PATCH 1/2] Keep track of ISA ports ISA device is using in qdev. Message-ID: <20101025181540.GB877@redhat.com> References: <1287928933-11423-1-git-send-email-gleb@redhat.com> <1287928933-11423-2-git-send-email-gleb@redhat.com> <20101025165803.GB31633@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: qemu-devel@nongnu.org On Mon, Oct 25, 2010 at 08:01:13PM +0200, Markus Armbruster wrote: > Gleb Natapov writes: > > > On Mon, Oct 25, 2010 at 05:06:51PM +0200, Markus Armbruster wrote: > >> Gleb Natapov writes: > >> > >> > Prevent two devices from claiming the same io port. > >> > >> Really? > >> > >> Your new check for double-claim is in the new isa_init_ioport(), which > >> is for ISADevice only. Thus, only qdevified ISA devices can opt for > >> this protection, by calling isa_init_ioport(). It doesn't protect from > >> devices who don't or can't opt in, such as PCI devices. > >> > > I didn't claim different. This obviously works only for ISA qdev > > devices. > > I read "Prevent two devices from claiming the same io port" as such. > And have you read subject with that? > >> Anyway, we already check for double-claim in > >> register_ioport_{read,write}(). The check has issues --- hw_error() is > >> wrong there for hot plug. But it's where the check should be, isn't it? > > You don't like double-claim checking? Forget about it (all 3 lines > > of code). The real point of the patch is to have ISA resources used > > by devices to be stored in common place (ISADevice) which allows > > get_dev_path() to be implemented. > > We already track I/O port use, in ioport.c. I don't like that > duplicated. Even less so if the dupe catches fewer double-claims than > the original. Consider it removed although we do keep track of irqs there and this tracking is also incomplete. Why is it there? > > Perhaps your new function should wrap around register_ioport_*() instead > of supplementing it. register_ioport_*() is disconnected from qdev in general and from ISADEvice in particular, so how "wrap around register_ioport_*()" will help me to have get_dev_path() for ISABus is beyond my understanding. -- Gleb.