From 163ea3c83aeeb3908a51162c79cb3a7c374d92b4 Mon Sep 17 00:00:00 2001 From: Tom Lendacky <thomas.lendacky@amd.com> Date: Mon, 17 Jul 2017 16:10:20 -0500 Subject: [PATCH] x86/realmode: Decrypt trampoline area if memory encryption is active MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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@amd.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: Dave Young <dyoung@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim KrÄmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Toshimitsu Kani <toshi.kani@hpe.com> Cc: kasan-dev@googlegroups.com Cc: kvm@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-efi@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/c70ffd2614fa77e80df31c9169ca98a9b16ff97c.1500319216.git.thomas.lendacky@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/x86/realmode/init.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c index cd4be19c36dc6..d6ddc7e608848 100644 --- a/arch/x86/realmode/init.c +++ b/arch/x86/realmode/init.c @@ -1,6 +1,7 @@ #include <linux/io.h> #include <linux/slab.h> #include <linux/memblock.h> +#include <linux/mem_encrypt.h> #include <asm/set_memory.h> #include <asm/pgtable.h> @@ -59,6 +60,13 @@ static void __init setup_real_mode(void) base = (unsigned char *)real_mode_header; + /* + * If SME is active, the trampoline area will need to be in + * decrypted memory in order to bring up other processors + * successfully. + */ + set_memory_decrypted((unsigned long)base, size >> PAGE_SHIFT); + memcpy(base, real_mode_blob, size); phys_base = __pa(base); -- GitLab