From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: Graphics pass-through Date: Wed, 11 May 2011 15:50:25 +0200 Message-ID: <4DCA9421.6060703@siemens.com> References: <4D415D70.8070105@web.de> <1296175554.2891.29.camel@x201> <4DC264CD.9080700@siemens.com> <1304608642.3081.35.camel@x201> <4DC7CCB3.8030607@siemens.com> <4DC807E3.4080706@siemens.com> <1304956091.26106.39.camel@x201> <4DCA7217.5020806@redhat.com> <4DCA8A66.4080304@siemens.com> <4DCA8E9E.8000705@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Alex Williamson , Prasad Joshi , =?UTF-8?B?QW5kcsOpIFdlaWRlbWFubg==?= , "kvm@vger.kernel.org" , Oswaldo Cadenas , "Nikolaev, Maxim" To: Avi Kivity Return-path: Received: from thoth.sbs.de ([192.35.17.2]:25810 "EHLO thoth.sbs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755769Ab1EKPun (ORCPT ); Wed, 11 May 2011 11:50:43 -0400 In-Reply-To: <4DCA8E9E.8000705@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 2011-05-11 15:26, Avi Kivity wrote: > On 05/11/2011 04:08 PM, Jan Kiszka wrote: >> On 2011-05-11 13:25, Avi Kivity wrote: >>> On 05/09/2011 06:48 PM, Alex Williamson wrote: >>>>> That's an interesting trace! We'll check this here, but I bet it >>>>> contributes to the problems. Our FX 3800 has 1G memory... >>>> >>>> Yes, qemu leaves far too little MMIO space to think about assigning >>>> graphics cards. Both of my cards have 512MB and I hacked qemu to leave >>>> a bigger gap via something like: >>>> >>> >>> What about 64-bit BARs? >> >> Aren't they backward compatible? Or do you think some guest drivers may >> assume to find their 64-bit capable bars also registered as such and get >> upset when seeing them as 32-bit ones? >> > > I mean, if you have a 1GB framebuffer, put it above 4GB and hope the > OS/driver can handle it. The question is if the drivers actually depend on this. At least the binary nvidia thing here on my notebook, it is obviously happy with below-4G-bars (and likely change the mapped window on demand): 01:00.0 VGA compatible controller: nVidia Corporation GT216 [Quadro FX 880M] (rev a2) (prog-if 00 [VGA controller]) Subsystem: Fujitsu Limited. Device 1584 Flags: bus master, fast devsel, latency 0, IRQ 16 Memory at cc000000 (32-bit, non-prefetchable) [size=16M] Memory at d0000000 (64-bit, prefetchable) [size=256M] Memory at ce000000 (64-bit, prefetchable) [size=32M] I/O ports at 2000 [size=128] [virtual] Expansion ROM at cd000000 [disabled] [size=512K] Capabilities: [60] Power Management version 3 Capabilities: [68] MSI: Enable- Count=1/1 Maskable- 64bit+ Capabilities: [78] Express Endpoint, MSI 00 Capabilities: [b4] Vendor Specific Information: Len=14 Capabilities: [100] Virtual Channel Capabilities: [128] Power Budgeting Capabilities: [600] Vendor Specific Information: ID=0001 Rev=1 Len=024 Kernel driver in use: nvidia Maybe the crashing Windows driver of the FX3800 has different requirements. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux