Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753755AbaLEIua (ORCPT ); Fri, 5 Dec 2014 03:50:30 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56404 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753677AbaLEIu1 (ORCPT ); Fri, 5 Dec 2014 03:50:27 -0500 Message-ID: <1417769421.11297.37.camel@nilsson.home.kraxel.org> Subject: Re: [ANNOUNCE][RFC] KVMGT - the implementation of Intel GVT-g(full GPU virtualization) for KVM From: Gerd Hoffmann To: Jike Song Cc: "intel-gfx@lists.freedesktop.org" , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, "Tian, Kevin" , "Cowperthwaite, David J" , "White, Michael L" , "Dong, Eddie" , "Li, Susie" , "Haron, Sandra" Date: Fri, 05 Dec 2014 09:50:21 +0100 In-Reply-To: <547FC5DE.4010701@intel.com> References: <547FC5DE.4010701@intel.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, > In KVMGT, we need to register an iodev only *after* BAR registers are > written by guest. Oh, the guest can write the bar register at any time. Typically it happens at boot only, but it can also happen at runtime, for example on reboot. I've also seen the kernel redoing the pci mappings created by the bios, due to buggy _crs declarations in the qemu acpi tables. > https://www.usenix.org/conference/atc14/technical-sessions/presentation/tian /me goes read this. A few comments on the kernel stuff (brief look so far, also compile-tested only, intel gfx on my test machine is too old). * Noticed the kernel bits don't even compile when configured as module. Everything (vgt, i915, kvm) must be compiled into the kernel. * Design approach still seems to be i915 on vgt not the other way around. Qemu/SeaBIOS bits: I've seen the host bridge changes identity from i440fx to copy-pci-ids-from-host. Guess the reason for this is that seabios uses this device to figure whenever it is running on i440fx or q35. Correct? What are the exact requirements for the device? Must it match the host exactly, to not confuse the guest intel graphics driver? Or would something more recent -- such as the q35 emulation qemu has -- be good enough to make things work (assuming we add support for the graphic-related pci config space registers there)? The patch also adds a dummy isa bridge at 0x1f. Simliar question here: What exactly is needed here? Would things work if we simply use the q35 lpc device here? more to come after I've read the paper linked above ... cheers, Gerd -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/