linux-stable/arch/x86/platform/efi
Ard Biesheuvel 37aee82c21 x86/efi: Drop support for fake EFI memory maps
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: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-07-02 00:26:24 +02:00
..
efi.c x86/efi: Drop support for fake EFI memory maps 2024-07-02 00:26:24 +02:00
efi_32.c efi/x86: Move EFI runtime call setup/teardown helpers out of line 2023-09-11 06:37:50 +00:00
efi_64.c efi/x86: Move EFI runtime call setup/teardown helpers out of line 2023-09-11 06:37:50 +00:00
efi_stub_32.S x86: Prepare asm files for straight-line-speculation 2021-12-08 12:25:37 +01:00
efi_stub_64.S x86: Prepare asm files for straight-line-speculation 2021-12-08 12:25:37 +01:00
efi_thunk_64.S efi/x86-mixed: move unmitigated RET into .rodata 2022-08-16 09:28:05 +02:00
Makefile x86/efi: Drop support for fake EFI memory maps 2024-07-02 00:26:24 +02:00
memmap.c x86/efi: Drop support for fake EFI memory maps 2024-07-02 00:26:24 +02:00
quirks.c efivarfs: expose used and total size 2023-05-17 18:21:34 +02:00
runtime-map.c efi: x86: make kobj_type structure constant 2023-05-10 19:00:40 +02:00