On Wed, 2012-03-28 at 12:05 +0200, Avi Kivity wrote: > That's strange, the cirrus BAR allows the framebuffer and bitblt region > to coexist: > > 0000000000000000-7ffffffffffffffe (prio 0, RW): pci > 00000000000a0000-00000000000bffff (prio 1, RW): cirrus-lowmem-container > 00000000000a0000-00000000000a7fff (prio 1, RW): alias vga.bank0 > @vga.vram 0000000000000000-0000000000007fff > 00000000000a0000-00000000000bffff (prio 0, RW): cirrus-low-memory > 00000000000a8000-00000000000affff (prio 1, RW): alias vga.bank1 > @vga.vram > > ^ those are continuously flipped when running 16-bit software > > 0000000000008000-000000000000ffff > 00000000000c0000-00000000000dffff (prio 1, RW): pc.rom > 00000000000e0000-00000000000fffff (prio 1, R-): isa-bios > 00000000fc000000-00000000fdffffff (prio 1, RW): cirrus-pci-bar0 > 00000000fc000000-00000000fc7fffff (prio 1, RW): vga.vram > 00000000fc000000-00000000fc7fffff (prio 0, RW): cirrus-linear-io > 00000000fd000000-00000000fd3fffff (prio 0, RW): cirrus-bitblt-mmio > > ^ the cirrus BAR, write to 0xfc000000 and you hit vga.vram, write to > 0xfd000000 and you trigger a bitblt. > > 00000000feba0000-00000000febbffff (prio 1, RW): e1000-mmio > 00000000febf0000-00000000febf0fff (prio 1, RW): cirrus-mmio > > A guest driver problem perhaps? Quite possibly, I'm not familiar with the cirrus HW. The trigger is an MMIO register write done by cirrusfb, which causes cirrus_update_memory_access() to switch the BAR to emulation as a result of this becoming true: s->cirrus_srcptr != s->cirrus_srcptr_end I haven't had a chance to dig further today (I'm home now), I can have a look tomorrow. Cheers, Ben. -- 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
