From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33996) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZHWxw-0002WK-K6 for qemu-devel@nongnu.org; Tue, 21 Jul 2015 08:48:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZHWxr-0006FR-10 for qemu-devel@nongnu.org; Tue, 21 Jul 2015 08:48:12 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45113) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZHWxq-0006FK-Sk for qemu-devel@nongnu.org; Tue, 21 Jul 2015 08:48:06 -0400 References: <55A158AF.8050907@redhat.com> <1436772752.26533.2.camel@redhat.com> <55A38FBD.4000203@redhat.com> <55AD46A3.6060308@redhat.com> <55AE3628.4010400@suse.de> From: Laszlo Ersek Message-ID: <55AE3F81.3070806@redhat.com> Date: Tue, 21 Jul 2015 14:48:01 +0200 MIME-Version: 1.0 In-Reply-To: <55AE3628.4010400@suse.de> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] selecting VIRTIO_INPUT and VIRTIO_VGA List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf , Paolo Bonzini , Gerd Hoffmann Cc: Marc Zyngier , Peter Maydell , qemu-devel , Ard Biesheuvel On 07/21/15 14:08, Alexander Graf wrote: > On 07/20/15 21:06, Laszlo Ersek wrote: >> Cc'ing Alex >> >> On 07/13/15 12:15, Paolo Bonzini wrote: >>> >>> On 13/07/2015 09:32, Gerd Hoffmann wrote: >>>>> and virtio-vga is only compiled on 64-bit Intel? >>>> There is virtio-gpu-pci ... >>>> >>>> Any specific reason why we need vga compatibility on !x86? >>> I was actually thinking about 32-bit x86. :) I agree that !x86 is not >>> necessary. >> I disagree :) >> >> (This is actually my more important followup to this thread; the other >> message I just couldn't resist sending.) >> >> Gerd recently contributed virtio-vga support to OvmfPkg/QemuVideoDxe: >> >> https://github.com/tianocore/edk2/commit/94210dc9 >> >> That support depends on vga compat. All fine. >> >> What's probably not obvious is that I had ported >> PcAtChipsetPkg/PciHostBridgeDxe to ArmVirtPkg -- which drives Alex's >> generic PCIe host bridge, exposed on qemu-system-(arm|aarch64) -M virt >> -- and included OvmfPkg/QemuVideoDxe in the ArmVirtQemu.dsc build too. >> >> That means you can currently stick a -device VGA into -M virt, and it >> will work. Since OvmfPkg/QemuVideoDxe recognizes virtio-vga (see edk2 > > For some definition of work, yes :). It will work perfectly fine with > TCG, you will run into cache coherency problems with KVM because the > guest maps MMIO regions (like the vram) as uncached while QEMU accesses > it as cached. Yes, I'm aware, I just didn't want to drag that thread into this discusson as well ;) > >> 94210dc9 again), and the driver is included by ArmVirtQemu.dsc, I think >> it would be probably useful to build the device model for arm/aarch64 >> targets too. >> >> See also QEMU commit 332261de2b (together with its parent commits). > > I agree. Also, as far as I understood Marc, his hope was that the fix to > halfway working VGA emulation would be virtio-gpu. Not sure how (if!) we're going to be able to drive that from the firmware! :) Thanks Laszlo