From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Lendacky Subject: Re: [RFC PATCH v2 07/20] x86: Provide general kernel support for memory encryption Date: Wed, 7 Sep 2016 09:19:36 -0500 Message-ID: <74f3288f-afc7-2170-89ff-a0334451da82@amd.com> References: <20160822223529.29880.50884.stgit@tlendack-t1.amdoffice.net> <20160822223646.29880.28794.stgit@tlendack-t1.amdoffice.net> <20160905152211.GD18856@pd.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20160905152211.GD18856@pd.tnic> Sender: linux-doc-owner@vger.kernel.org To: Borislav Petkov Cc: linux-arch@vger.kernel.org, linux-efi@vger.kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, iommu@lists.linux-foundation.org, =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Arnd Bergmann , Jonathan Corbet , Matt Fleming , Joerg Roedel , Konrad Rzeszutek Wilk , Andrey Ryabinin , Ingo Molnar , Andy Lutomirski , "H. Peter Anvin" , Paolo Bonzini , Alexander Potapenko , Thomas Gleixner , Dm List-Id: linux-efi@vger.kernel.org On 09/05/2016 10:22 AM, Borislav Petkov wrote: > On Mon, Aug 22, 2016 at 05:36:46PM -0500, Tom Lendacky wrote: >> Adding general kernel support for memory encryption includes: >> - Modify and create some page table macros to include the Secure Memory >> Encryption (SME) memory encryption mask >> - Update kernel boot support to call an SME routine that checks for and >> sets the SME capability (the SME routine will grow later and for now >> is just a stub routine) >> - Update kernel boot support to call an SME routine that encrypts the >> kernel (the SME routine will grow later and for now is just a stub >> routine) >> - Provide an SME initialization routine to update the protection map with >> the memory encryption mask so that it is used by default >> >> Signed-off-by: Tom Lendacky > > ... > >> diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S >> index c98a559..30f7715 100644 >> --- a/arch/x86/kernel/head_64.S >> +++ b/arch/x86/kernel/head_64.S >> @@ -95,6 +95,13 @@ startup_64: >> jnz bad_address >> >> /* >> + * Enable memory encryption (if available). Add the memory encryption >> + * mask to %rbp to include it in the the page table fixup. >> + */ >> + call sme_enable >> + addq sme_me_mask(%rip), %rbp >> + >> + /* >> * Fixup the physical addresses in the page table >> */ >> addq %rbp, early_level4_pgt + (L4_START_KERNEL*8)(%rip) >> @@ -116,7 +123,8 @@ startup_64: >> movq %rdi, %rax >> shrq $PGDIR_SHIFT, %rax >> >> - leaq (4096 + _KERNPG_TABLE)(%rbx), %rdx >> + leaq (4096 + __KERNPG_TABLE)(%rbx), %rdx >> + addq sme_me_mask(%rip), %rdx /* Apply mem encryption mask */ > > Please add comments over the line and not at the side... Ok, will do. Thanks, Tom >