On Thu, 2012-09-13 at 11:40 +0200, Lennert Buytenhek wrote: > On Thu, Sep 13, 2012 at 07:55:00AM +0200, Gerd Hoffmann wrote: > > > Hi, > > Hi, > > > > > - Apply the patches at the end of this mail to kvm and SeaBIOS to > > > allow for more BAR space under 4G. (The relevant BARs on the > > > graphics cards _are_ 64 bit BARs, but kvm seemed to turn those > > > into 32 bit BARs in the guest.) > > > > Which qemu/seabios versions have you used? > > > > qemu-1.2 (+ bundled seabios) should handle that just fine without > > patching. There is no fixed I/O window any more, all memory space above > > lowmem is available for pci, i.e. if you give 2G to your guest > > everything above 0x80000000. > > > > And if there isn't enougth address space below 4G (if you assign lot of > > memory to your guest so qemu keeps only the 0xe0000000 - 0xffffffff > > window free) seabios should try to map 64bit bars above 4G. > > This was some time ago, on (L)ubuntu 12.04, which has qemu-kvm 1.0 > and seabios 0.6.2. We'll retry on a newer distro soon. > > > > > - Apply the hacky patch at the end of this mail to SeaBIOS to > > > always skip initialising the Radeon's option ROMs, or the VM > > > would hang inside the Radeon option ROM if you boot the VM > > > without the default cirrus video. > > > > A better way to handle that would probably be to add an pci passthrough > > config option to not expose the rom to the guest. > > > > Any clue *why* the rom doesn't run? > > No idea, we didn't look into that -- this was just a one afternoon > hacking session. Thanks for the report. Spawned by your success, I tested a Radeon HD 5450 using VFIO based device assignment. I can get it to work on Windows XP, with no changes (from the version I'll post soon), but Win7 dies (still need to play around more with your suggestions of cpu type). For skipping the option rom, is it sufficient to not expose it (rombar=0) or does the guest OS driver need it as well? Thanks, Alex -- 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
