On Tue, 2012-08-07 at 11:50 +0100, Jan Beulich wrote: > > > > I managed to find a machine to reproduce this on and it looks like the > > ASUS firmware engineers are upto their old tricks of referencing > > physical addresses after we've taken control of the memory map, > > Yippie. On such systems we simply can't do any runtime calls. > Should we add a command line option forcing efi_native to false, > thus suppressing all runtime calls? Or would the "noefi" one be > enough already?
I think a better solution for this, seeing as there appear to be *so* many ASUS machines in the wild with this inability to do virtual EFI calls, is to provide a 1:1 mapping as well as our regular virt->phys mapping for the benefit of the firmware. We can load our special page table in efi_call_*, etc. One thing to note is that because of breakage seen on Apple machines last time Matthew tried this approach, we (the kernel) can't actually access the 1:1 mapping, it would exist purely for the benefit of firmware that was broken enough to reference physical addresses after SetVirtualAddressMap(). -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
