On 2011-05-11 15:54, Avi Kivity wrote: > On 05/11/2011 04:50 PM, Jan Kiszka wrote: >> 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. > > I doubt it. A 64-bit BAR would be configured as 32-bit on an older > BIOS, no? > > I'd guess 64-bit BARs are only needed for large BARs. > The BIOS can't configure the bars to 64 bit as it does not know which type of OS (32 or 64 bits) is going to pick them up. But maybe 64-bit Windows reconfigures the bars before it starts the driver. Would we support this? Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
