From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:60157) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QMiVC-00017L-My for qemu-devel@nongnu.org; Wed, 18 May 2011 11:17:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QMiVB-0005gk-8b for qemu-devel@nongnu.org; Wed, 18 May 2011 11:17:34 -0400 Received: from mail-iw0-f173.google.com ([209.85.214.173]:65108) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QMiVB-0005ga-5b for qemu-devel@nongnu.org; Wed, 18 May 2011 11:17:33 -0400 Received: by iwl42 with SMTP id 42so1631212iwl.4 for ; Wed, 18 May 2011 08:17:32 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <4DD3E1B3.3020405@siemens.com> References: <4DD3C5B9.1080908@redhat.com> <4DD3D236.90708@siemens.com> <4DD3D95E.2060105@redhat.com> <4DD3E1B3.3020405@siemens.com> Date: Wed, 18 May 2011 16:17:32 +0100 Message-ID: From: Peter Maydell Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [RFC] Memory API List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: Avi Kivity , qemu-devel On 18 May 2011 16:11, Jan Kiszka wrote: > On 2011-05-18 16:36, Avi Kivity wrote: >> There is nothing we can do with a return code. =C2=A0You can't fail an m= mio >> that causes overlapping physical memory map. > > We must fail such requests to make progress with the API. That may > happen either on caller side or in cpu_register_memory_region itself > (hwerror). Otherwise the new API will just be a shiny new facade for on > old and still fragile building. If we don't allow overlapping regions, then how do you implement things like "on startup board maps ROM into lower addresses over top of devices, but later it is unmapped and you can see the underlying devices" ? (You can't currently do this AFAIK, and it would be nice if the new API supported it.) -- PMM