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| author | Ard Biesheuvel <ardb@kernel.org> | 2024-06-20 09:10:49 +0200 |
|---|---|---|
| committer | Ard Biesheuvel <ardb@kernel.org> | 2024-07-02 00:26:24 +0200 |
| commit | 37aee82c213d352dccb850dc4228dda2e7e591b1 (patch) | |
| tree | 9d85222c219bb5ccd4ae1e0070de9514e6f7f339 /arch/x86/Kconfig | |
| parent | f2661062f16b2de5d7b6a5c42a9a5c96326b8454 (diff) | |
| download | linux-37aee82c213d352dccb850dc4228dda2e7e591b1.tar.gz linux-37aee82c213d352dccb850dc4228dda2e7e591b1.tar.bz2 linux-37aee82c213d352dccb850dc4228dda2e7e591b1.zip | |
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>
Diffstat (limited to 'arch/x86/Kconfig')
| -rw-r--r-- | arch/x86/Kconfig | 20 |
1 files changed, 0 insertions, 20 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 1d7122a1883e..0c31f65aeb1d 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2038,26 +2038,6 @@ config EFI_MIXED If unsure, say N. -config EFI_FAKE_MEMMAP - bool "Enable EFI fake memory map" - depends on EFI - help - Saying Y here will enable "efi_fake_mem" boot option. By specifying - this parameter, you can add arbitrary attribute to specific memory - range by updating original (firmware provided) EFI memmap. This is - useful for debugging of EFI memmap related feature, e.g., Address - Range Mirroring feature. - -config EFI_MAX_FAKE_MEM - int "maximum allowable number of ranges in efi_fake_mem boot option" - depends on EFI_FAKE_MEMMAP - range 1 128 - default 8 - help - Maximum allowable number of ranges in efi_fake_mem boot option. - Ranges can be set up to this value using comma-separated list. - The default value is 8. - config EFI_RUNTIME_MAP bool "Export EFI runtime maps to sysfs" if EXPERT depends on EFI |