From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:45011) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ui6lu-0001ef-Ho for qemu-devel@nongnu.org; Thu, 30 May 2013 13:36:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Ui6ln-0002Ay-0f for qemu-devel@nongnu.org; Thu, 30 May 2013 13:36:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39338) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ui6lm-0002AV-Oa for qemu-devel@nongnu.org; Thu, 30 May 2013 13:36:10 -0400 Message-ID: <51A78E51.2050208@redhat.com> Date: Thu, 30 May 2013 19:37:21 +0200 From: Laszlo Ersek MIME-Version: 1.0 References: <20130523124132.GA18596@redhat.com> <20130528235309.GA31648@morn.localdomain> <51A5C117.6000609@redhat.com> <871u8p92v8.fsf@codemonkey.ws> <1369905828.20691.50.camel@shinybook.infradead.org> <51A73459.2020407@redhat.com> <1369916358.5141.32.camel@i7.infradead.org> <51A78152.10000@redhat.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [SeaBIOS] KVM call agenda for 2013-05-28 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jordan Justen Cc: KVM devel mailing list , Juan Quintela , "Jordan Justen (Intel address)" , seabios@seabios.org, qemu-devel qemu-devel , Kevin O'Connor , "Michael S. Tsirkin" , Gerd Hoffmann , Anthony Liguori , David Woodhouse On 05/30/13 18:57, Jordan Justen wrote: > On Thu, May 30, 2013 at 9:41 AM, Laszlo Ersek wrote: >> On 05/30/13 18:20, Jordan Justen wrote: >>> I think ACPI table generation lives in firmware on real products, >>> because on real products the firmware is the point that best >>> understands the actual hardware layout for the machine. In qemu, I >>> would say that qemu best knows the hardware layout, given that the >>> firmware is generally a slightly separate project from qemu. >>> >>> I don't think adding a coreboot layer into the picture helps, if it >>> brings along the coreboot payload boot interface as a requirement. >>> >>> Then again, I don't really understand how firmware could be swapped >>> out in this case. What would -bios do? How would the coreboot ACPI >>> shim layer be specified to qemu? >> >> I guess -bios would load coreboot. Coreboot would siphon the data >> necessary for ACPI table building through the current (same) fw_cfg >> bottleneck, build the tables, load the boot firmware (SeaBIOS or OVMF or >> something else -- not sure how to configure that), and pass down the >> tables to the firmware (through a now unspecified interface -- perhaps >> the tables could even be installed at this point). This could introduce >> another interface (fw_cfg+something rather than just fw_cfg), but ACPI >> table preparation would be concentrated in one project. >> >> I guess. > > For reference, I believe that both Xen and virtualbox build ACPI table > in the VMM rather than firmware. They both dump the tables into the > 0xe000 segment (yuck) where firmware finds and publishes it to the OS. > I think fw-cfg would be a reasonable alternative to this for > communicating the tables. I think Xen uses a separate utility called "hvmloader" that runs in the domU. - http://thread.gmane.org/gmane.comp.bios.coreboot.seabios/5453/focus=5668 - http://xenbits.xen.org/gitweb/?p=xen.git;a=tree;f=tools/firmware/hvmloader - http://thread.gmane.org/gmane.comp.bios.coreboot.seabios/6255/focus=110562 Laszlo