From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43086) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YDFVf-0002sU-HN for qemu-devel@nongnu.org; Mon, 19 Jan 2015 11:49:04 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YDFVe-00079W-Ir for qemu-devel@nongnu.org; Mon, 19 Jan 2015 11:49:03 -0500 Message-ID: <54BD3557.9040706@ilande.co.uk> Date: Mon, 19 Jan 2015 16:48:23 +0000 From: Mark Cave-Ayland MIME-Version: 1.0 References: <1421667328-11800-1-git-send-email-mark.cave-ayland@ilande.co.uk> <1421667328-11800-3-git-send-email-mark.cave-ayland@ilande.co.uk> <54BCFC57.3010709@redhat.com> In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 2/2] m48t59: add mem_base value to m48t59_init_isa() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell , Artyom Tarasenko Cc: Paolo Bonzini , "qemu-ppc@nongnu.org" , qemu-devel , =?UTF-8?B?QW5kcmVhcyBGw6RyYmVy?= , Alexander Graf On 19/01/15 15:04, Peter Maydell wrote: > On 19 January 2015 at 12:57, Artyom Tarasenko wrote: >> But out of curiosity, would it be possible to have a sysbus device >> somewhere in a middle of PCI space? Do sysbus devices have higher >> priority if the address spaces overlap? Or do you mean that the PCI >> controller needs to be modified to have a hole for a sysbus device? > > You can specify the priority when you map devices into a MemoryRegion, > so you can handle this by either making the sysbus device a positive > priority or by making the PCI window have a negative priority. > > (We don't actually get this right on x86 currently, > which has resulted in some awkwardness for the PPC desire to > make PCI address 0 valid.) I'm not sure this would work for SPARC64 since potentially OpenBIOS can program the I/O BAR for the ebus anywhere (and the NVRAM is located on the ebus). At the moment we cheat by creating an alias to I/O space at the top of memory so that OpenBIOS can always access it at a fixed address. ATB, Mark.