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authorTom Lendacky <thomas.lendacky@amd.com>2017-07-17 16:10:20 -0500
committerIngo Molnar <mingo@kernel.org>2017-07-18 11:38:03 +0200
commit163ea3c83aeeb3908a51162c79cb3a7c374d92b4 (patch)
treebee4b012beae5ce540c276da0dc30ff808b7ddd6
parent77bd2342d4304bda7896c953d424d15deb314ca3 (diff)
downloadlwn-163ea3c83aeeb3908a51162c79cb3a7c374d92b4.tar.gz
lwn-163ea3c83aeeb3908a51162c79cb3a7c374d92b4.zip
x86/realmode: Decrypt trampoline area if memory encryption is active
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 Krčmář <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>
-rw-r--r--arch/x86/realmode/init.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c
index cd4be19c36dc..d6ddc7e60884 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);