From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gustav Sorenson Subject: Re: AMD integrated graphics passthrough to KVM guest Date: Fri, 12 Jul 2013 20:18:36 +0200 Message-ID: References: <1373644471.8441.126.camel@ul30vt.home> <1373646809.8441.136.camel@ul30vt.home> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: kvm@vger.kernel.org To: Alex Williamson Return-path: Received: from mail-wi0-f196.google.com ([209.85.212.196]:64103 "EHLO mail-wi0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965205Ab3GLSSh (ORCPT ); Fri, 12 Jul 2013 14:18:37 -0400 Received: by mail-wi0-f196.google.com with SMTP id m6so212978wiv.11 for ; Fri, 12 Jul 2013 11:18:36 -0700 (PDT) In-Reply-To: <1373646809.8441.136.camel@ul30vt.home> Sender: kvm-owner@vger.kernel.org List-ID: Hello, > Ok, I have an X500 and I've never been able to get it to work correctly > for passthrough. It has additional quirks required beyond what either > my HD5450 or HD7850 require. Also, these old devices have a weird > co-processor secondary function (see 01:00.1 in your lspci). It > probably needs to be co-assigned, but I'm not really sure what it does. > FWIW, I don't think it's worth bothering to add support for anything > older than a Radeon HD5xxx (I'd say HD6xxx, but I happen to have the > HD5450 and it works, so...) You're probably right that for old cards the demand isn't high enough to justify the time spent. I don't plan to use the X1300 actively anyway. My plan was to initially buy the hardware as I have now, get VGA passthrough of the integrated GPU to work, and then add another more powerful (HD6xxx most probably) PCIe device, so that I could have a headless host and two 3D-accelerated VMs. Now that this seemingly won't work, I'd be happy if at least I could run the IGP on the host and pass the not-yet-bought dedicated GPU to a guest. So, in order to not again discover that my plans won't work out after I already bought the hardware, could you please tell me whether you have any problems with your graphics cards in guests? Xen users seem to suffer degraded performance after their guest systems shut down/reboot. Is this the case with KVM and VFIO as well? Any other issues, or models I should/should not buy? Of course I've done some research on my own, but the VGA virtualization topic seems to be quite volatile right now, and I find contradicting information. > One reason you're probably not getting any output is because the device > doesn't have a ROM (ie. there's no video BIOS to run to get seabios to > POST the device). You'll either need to find a VBIOS for the device or > use it as a secondary graphics device in the guest. In some cases you > can rip this out of the system ROM or ACPI tables. > > I don't think that using the vfio-vga-reset branches is helping you > since it's a root complex device and we can't do a reset even if we knew > how and if you use it as a secondary device, you might not even need the > x-vga=on option for VFIO (ie. VFIO would handle this just like any > regular PCI device). Thanks, Are you implying that I should be able to use the integrated GPU (if it's not the primary, I suppose) as a secondary for a guest? If so, do you expect 3D acceleration to work? Thank you very much for your help, it's highly appreciated.