On Fri, 16 Jun, at 01:53:26PM, Tom Lendacky wrote: > Boot data (such as EFI related data) is not encrypted when the system is > booted because UEFI/BIOS does not run with SME active. In order to access > this data properly it needs to be mapped decrypted. > > Update early_memremap() to provide an arch specific routine to modify the > pagetable protection attributes before they are applied to the new > mapping. This is used to remove the encryption mask for boot related data. > > Update memremap() to provide an arch specific routine to determine if RAM > remapping is allowed. RAM remapping will cause an encrypted mapping to be > generated. By preventing RAM remapping, ioremap_cache() will be used > instead, which will provide a decrypted mapping of the boot related data. > > Signed-off-by: Tom Lendacky <thomas.lendacky at amd.com> > --- > arch/x86/include/asm/io.h | 5 + > arch/x86/mm/ioremap.c | 179 +++++++++++++++++++++++++++++++++++++++++++++ > include/linux/io.h | 2 + > kernel/memremap.c | 20 ++++- > mm/early_ioremap.c | 18 ++++- > 5 files changed, 217 insertions(+), 7 deletions(-) Reviewed-by: Matt Fleming <matt at codeblueprint.co.uk>
