From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42789) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WhI2U-0005vu-JB for qemu-devel@nongnu.org; Mon, 05 May 2014 08:30:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WhI2L-0008B9-J3 for qemu-devel@nongnu.org; Mon, 05 May 2014 08:30:34 -0400 Received: from mail-ee0-x235.google.com ([2a00:1450:4013:c00::235]:51862) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WhI2L-0008Ay-CH for qemu-devel@nongnu.org; Mon, 05 May 2014 08:30:25 -0400 Received: by mail-ee0-f53.google.com with SMTP id b15so4176828eek.26 for ; Mon, 05 May 2014 05:30:24 -0700 (PDT) Date: Mon, 5 May 2014 14:30:07 +0200 From: Stefan Hajnoczi Message-ID: <20140505123007.GH16173@stefanha-thinkpad.redhat.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] E1000 emulation in qemu and pci configuration space List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Ayaz Akram Cc: qemu-devel@nongnu.org On Mon, May 05, 2014 at 02:15:05PM +0500, Ayaz Akram wrote: > Does e1000's emulation in QEMU require that the guest set its base address > register(pci configuration space register) or qemu has default value for > its base address register? There is no default. Drivers for some operating systems (Mac OS X?) may assume the device state set up by the firmware (UEFI). It's nasty to do that but it happens. Since QEMU's firmware is different from that on real machines a hack may be necessary to make the guest OS driver work. That hack shouldn't be in QEMU's device emulation code though - putting it into the guest firmware is closest to how the physical machine works. Stefan