On Thu, Oct 08, 2009 at 10:29:53PM -0400, Kevin O'Connor wrote: > Hi Michael, > > On Thu, Oct 08, 2009 at 05:53:46PM +0200, Michael S. Tsirkin wrote: > > VGA adapters need to claim memory and i/o > > transactions even if they do not have any > > i/o or memory bars. E.g. PCI spec, page 297, > > gives an example of such a device: > > > > Programming interface 0000 0000b > > VGA-compatible controller. Memory > > addresses 0A 0000h through 0B > > FFFFh. I/O addresses 3B0h to 3BBh > > and 3C0h to 3DFh and all aliases of > > these addresses. > > > > While we could check for these devices and special-case them, it is > > easier to fix this by enabling i/o and memory space unconditionally: > > devices that do not support it will just ignore this setting. > > This doesn't sound correct to me - I would think the vga option rom > should enable the memory and io bars. You can do this, but in real systems, BIOS enables memory on all devices. Just take a real system and do lspci -v on a device that has no driver loaded. And note how seabios does this *already* - it just doesn't enable I/O for VGA device unless it has I/O bar, which is wrong. > I don't have enough knowledge > to say for sure though - can someone else with knowledge in this area > confirm this approach? > > -Kevin -- 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
