From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Wargo Subject: Re: Windows 8 VGA Passthrough Date: Sun, 27 Oct 2013 09:27:37 -0500 Message-ID: <526D22D9.6010006@gmail.com> References: <526C2D06.1030606@gmail.com> <526CDD22.6080107@bobich.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <526CDD22.6080107@bobich.net> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Gordan Bobic , "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org On 10/27/2013 04:30 AM, Gordan Bobic wrote: > On 10/26/2013 09:58 PM, John Wargo wrote: >> Geniuses, >> >> I've been trying to get VGA pass-through working on Windows 8, however >> I've been running into a few issues. >> Currently I can get Windows 8 running flawlessly without VGA >> pass-through, however I'm planning on using it for gaming, so this wont >> work. >> >> When I start windows 8, I am able to get past the install portion of the >> DVD, however it hangs on "Getting devices ready.. (n%)". >> >> Hardware Information : >> AMD Fx6300 >> ASUS M5a99x evo r2.0 >> 16GB RAM >> 6670 Radeon HD - Dom0 >> 7850 Radeon HD - Win8 > > I have recently (recently as in over the past 48 hours) re-tried to > get ATI VGA passthrough working, and the results are... interesting. > > HD4850 dom0 + HD7450 domU worked fine - or as fine as ATI passthrough > ever seems to work (slowdown + white lines when dragging windows after > a domU reboot). I am using XP64 domU so I can't eject the GPU (it says > it is being used). But shutting down the domU, doing echo 1 > reset > for the GPU from dom0 (I don't know how this is implemented and > whether it does anything) and then starting it up again sometimes > recovers it. GPU-Z runs and reports the GPU correctly. > > HD4850 dom0 + HD7970 domU results in the entire host locking up as > soon as the driver is loaded in domU. My solution is to swap the dom0 > GPU for an 8800GT, and the problem now doesn't occur. If I had to > guess, BIOS on the HD7970 does something bizzare, finds the HD4850 on > the bus, tries to do something to it, and ends up crashing the host. > This could also be exacerbated by the fact that I have to run with > relaxed checking and no PCI ACS due to NF200 bridges on my > motherboard. Even so, however, GPU-Z crashes the domU and it's GPU > _hard_ (but not the host, thankfully). It crashes it so hard, that the > only cure is to reboot the host. Reseting the GPU via /sys/ doesn't > seem to do anything to help. > > Are you using gfx_passthru=1 in your config? The way most people have > this kind of thing working is with gfx_passthru=0, i.e. secondary > passthru. Don't assign the PCI device in the config when installing. > Once the domU install is complete, shut it down, and add the GPU you > want to pass through. Then fire up domU in VNC, install the driver, > and with a bit of luck it will come up with output on the external > monitor. > > Also make sure that radeon or radeonfb kernel drivers DO NOT load > before the device is assigned to xen-pciback. The exact way to ensure > this will depend on what distro and dom0 kernel you are using. > > Gordan Status update: The catalyst drivers appear to be working perfectly fine, device manager shows no errors, and everything works great, except that when I plug my monitor into the second card, I get "No Signal" on the monitor, then it shuts off. I though that secondary passthrough meant that it would pass the virtual adapter in as primary, but I could use my GPU that I passed through, so where am I wrong, and how do I do that? -John