Messages in this thread | | | Date | Tue, 16 Aug 2016 15:29:33 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH] Map in physical addresses in efi_map_region_fixed |
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On Tue, Aug 16, 2016 at 01:30:28PM +0100, Matt Fleming wrote: > That's impossible, because that would mean we loaded the kexec kernel > over the top of physical pages of EFI services. We still need to be > able to invoke EFI services from kexec - we just can't change their > virtual mappings.
Which would mean that whatever comes second - kexec reservation or 1:1 mappings - won't work.
> This is because of the way that the SGI firmware works and that the > "new" virtual address mappings are usable on SGI+kexec now.
My only issue is that we probably should've aimed for avoiding that...
> No, some Apple platforms will not boot if SetVirtualAddressMap() > passes 1:1 mappings, and we only enter the firmware via the 1:1 > mappings for EFI mixed mode calls. We're still using the virtual > runtime mappings in the commit you reference below most of the time.
... but reasons like the above are making us run the kexec kernel with the exact-same mappings as the boot kernel. Probably not really a big deal since we have our own pagetable...
-- Regards/Gruss, Boris.
ECO tip #101: Trim your mails when you reply. --
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