From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:54602) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1StzDr-0004AM-Rc for qemu-devel@nongnu.org; Wed, 25 Jul 2012 06:53:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1StzDq-0007z6-TX for qemu-devel@nongnu.org; Wed, 25 Jul 2012 06:53:43 -0400 Received: from gate.crashing.org ([63.228.1.57]:36034) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1StzDq-0007yv-JH for qemu-devel@nongnu.org; Wed, 25 Jul 2012 06:53:42 -0400 Message-ID: <1343213618.3715.48.camel@pasglop> From: Benjamin Herrenschmidt Date: Wed, 25 Jul 2012 20:53:38 +1000 In-Reply-To: <500FC9F8.6010002@redhat.com> References: <1343188660.3715.41.camel@pasglop> <500FC9F8.6010002@redhat.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Subject: Re: [Qemu-devel] vga-pci and MMIO BAR List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Avi Kivity Cc: qemu-devel@nongnu.org On Wed, 2012-07-25 at 13:27 +0300, Avi Kivity wrote: > On 07/25/2012 06:57 AM, Benjamin Herrenschmidt wrote: > > Hi folks ! > > > > Would there be any objection to adding a second MMIO BAR to qemu-vga > > which mirrors the bochs magic VBE ports ? > > > > Support for IO space is optional in PCIe and can be problematic on some > > architectures, it would be nice to be able to program the card entirely > > using mmio. > > Can we choose a PCIe chipset that does support IO space? Why bother ? It's not like mode setting is performance critical and IO space is always going to be a pain on non-x86 ... > If not, we can add a second BAR, but it should disappear when running an > older machine type. Well, the IO ports in legacy space are still there. We can also make the "register BAR" exist in both mode or we can add a second BAR and have x86 "prefer" IO... whatever rocks your boat as long as it's a BAR, it's the legacy hole that's annoying for me :-) > > Once done, I'd like to look into doing a qemudrmfb similar to the cirrus > > one that pretty much gives you generic KMS support (with RandR) on top > > of vga-pci. This would have the advantage of potentially lifting the > > pitch and size limitations that plague cirrus. > > Have a look at qxl. No I haven't :-) I'll have a look, thanks. Cheers, Ben.