• Ard Biesheuvel's avatar
    x86/efi: Drop support for fake EFI memory maps · 37aee82c
    Ard Biesheuvel authored
    Between kexec and confidential VM support, handling the EFI memory maps
    correctly on x86 is already proving to be rather difficult (as opposed
    to other EFI architectures which manage to never modify the EFI memory
    map to begin with)
    
    EFI fake memory map support is essentially a development hack (for
    testing new support for the 'special purpose' and 'more reliable' EFI
    memory attributes) that leaked into production code. The regions marked
    in this manner are not actually recognized as such by the firmware
    itself or the EFI stub (and never have), and marking memory as 'more
    reliable' seems rather futile if the underlying memory is just ordinary
    RAM.
    
    Marking memory as 'special purpose' in this way is also dubious, but may
    be in use in production code nonetheless. However, the same should be
    achievable by using the memmap= command line option with the ! operator.
    
    EFI fake memmap support is not enabled by any of the major distros
    (Debian, Fedora, SUSE, Ubuntu) and does not exist on other
    architectures, so let's drop support for it.
    Acked-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
    Acked-by: default avatarDan Williams <dan.j.williams@intel.com>
    Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
    37aee82c
memmap.c 6.28 KB