From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Lendacky Subject: [PATCH v5 21/32] x86, realmode: Decrypt trampoline area if memory encryption is active Date: Tue, 18 Apr 2017 16:19:59 -0500 Message-ID: <20170418211959.10190.3481.stgit@tlendack-t1.amdoffice.net> References: <20170418211612.10190.82788.stgit@tlendack-t1.amdoffice.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170418211612.10190.82788.stgit-qCXWGYdRb2BnqfbPTmsdiZQ+2ll4COg0XqFh9Ls21Oc@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kasan-dev-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Cc: Thomas Gleixner , Rik van Riel , Brijesh Singh , Toshimitsu Kani , Arnd Bergmann , Jonathan Corbet , Matt Fleming , Radim =?utf-8?b?S3LEjW3DocWZ?= , Andrey Ryabinin , Ingo Molnar , "Michael S. Tsirkin" , Andy Lutomirski , "H. Peter Anvin" , Borislav Petkov , Paolo Bonzini , Alexander Potapenko , Dave Young , Larry Woodman , Dmitry Vyukov List-Id: linux-efi@vger.kernel.org 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 --- arch/x86/realmode/init.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c index 5db706f1..21d7506 100644 --- a/arch/x86/realmode/init.c +++ b/arch/x86/realmode/init.c @@ -6,6 +6,8 @@ #include #include #include +#include +#include struct real_mode_header *real_mode_header; u32 *trampoline_cr4_features; @@ -130,6 +132,16 @@ static void __init set_real_mode_permissions(void) unsigned long text_start = (unsigned long) __va(real_mode_header->text_start); + /* + * If SME is active, the trampoline area will need to be in + * decrypted memory in order to bring up other processors + * successfully. + */ + if (sme_active()) { + sme_early_decrypt(__pa(base), size); + set_memory_decrypted((unsigned long)base, size >> PAGE_SHIFT); + } + set_memory_nx((unsigned long) base, size >> PAGE_SHIFT); set_memory_ro((unsigned long) base, ro_size >> PAGE_SHIFT); set_memory_x((unsigned long) text_start, text_size >> PAGE_SHIFT);