On 11/17/2016 12:09 PM, Borislav Petkov wrote: > On Wed, Nov 09, 2016 at 06:37:08PM -0600, Tom Lendacky wrote: >> When Secure Memory Encryption is enabled, the trampoline area must not >> be encrypted. A CPU running in real mode will not be able to decrypt >> memory that has been encrypted because it will not be able to use addresses >> with the memory encryption mask. >> >> Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx> >> --- >> arch/x86/realmode/init.c | 9 +++++++++ >> 1 file changed, 9 insertions(+) >> >> diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c >> index 5db706f1..44ed32a 100644 >> --- a/arch/x86/realmode/init.c >> +++ b/arch/x86/realmode/init.c >> @@ -6,6 +6,7 @@ >> #include <asm/pgtable.h> >> #include <asm/realmode.h> >> #include <asm/tlbflush.h> >> +#include <asm/mem_encrypt.h> >> >> struct real_mode_header *real_mode_header; >> u32 *trampoline_cr4_features; >> @@ -130,6 +131,14 @@ static void __init set_real_mode_permissions(void) >> unsigned long text_start = >> (unsigned long) __va(real_mode_header->text_start); >> >> + /* >> + * If memory encryption is active, the trampoline area will need to >> + * be in un-encrypted memory in order to bring up other processors >> + * successfully. >> + */ >> + sme_early_mem_dec(__pa(base), size); >> + sme_set_mem_unenc(base, size); > > We're still unsure about the non-encrypted state: dec vs unenc. Please > unify those for ease of use, code reading, etc etc. > > sme_early_decrypt(__pa(base), size); > sme_mark_decrypted(base, size); > > or similar looks much more readable and understandable to me. Yeah, I'll go through and change everything so that the implication or action is expressed better. Thanks, Tom > -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
