x86, efi: 1:1 pagetable mapping for virtual EFI calls
Some firmware still needs a 1:1 (virt->phys) mapping even after we've called SetVirtualAddressMap(). So install the mapping alongside our existing kernel mapping whenever we make EFI calls in virtual mode. This bug was discovered on ASUS machines where the firmware implementation of GetTime() accesses the RTC device via physical addresses, even though that's bogus per the UEFI spec since we've informed the firmware via SetVirtualAddressMap() that the boottime memory map is no longer valid. This bug seems to be present in a lot of consumer devices, so there's not a lot we can do about this spec violation apart from workaround it. Cc: JérômeCarretero <cJ-ko@zougloub.eu> Cc: Vasco Dias <rafa.vasco@gmail.com> Acked-by:Jan Beulich <jbeulich@suse.com> Signed-off-by:
Matt Fleming <matt.fleming@intel.com>
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53b87cf0
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