[RFC PATCH v1 11/28] x86: Don't decrypt trampoline area if SEV is active
From: Brijesh Singh <hidden>
Date: 2016-08-22 23:59:56
Also in:
kvm, linux-efi, lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Tom Lendacky <thomas.lendacky@amd.com> When Secure Encrypted Virtualization is active instruction fetches are always interpreted as being from encrypted memory so the trampoline area must remain encrypted when SEV is active. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> --- arch/x86/realmode/init.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c
index c3edb49..f3207e5 100644
--- a/arch/x86/realmode/init.c
+++ b/arch/x86/realmode/init.c@@ -138,10 +138,13 @@ static void __init set_real_mode_permissions(void) /* * If memory encryption is active, the trampoline area will need to * be in non-encrypted memory in order to bring up other processors - * successfully. + * successfully. This only applies to SME, SEV requires the trampoline + * to be encrypted. */ - sme_early_mem_dec(__pa(base), size); - sme_set_mem_dec(base, size); + if (!sev_active) { + sme_early_mem_dec(__pa(base), size); + sme_set_mem_dec(base, size); + } set_memory_nx((unsigned long) base, size >> PAGE_SHIFT); set_memory_ro((unsigned long) base, ro_size >> PAGE_SHIFT); --
To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>