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authorTom Lendacky <thomas.lendacky@amd.com>2017-07-18 00:10:07 +0300
committerIngo Molnar <mingo@kernel.org>2017-07-18 12:38:00 +0300
commit21729f81ce8ae76a6995681d40e16f7ce8075db4 (patch)
tree20fc96d3f1970ef516d27ed3e48305b6a24461ed /arch/x86/mm/pageattr.c
parentfd7e315988b784509ba3f1b42f539bd0b1fca9bb (diff)
downloadlinux-21729f81ce8ae76a6995681d40e16f7ce8075db4.tar.xz
x86/mm: Provide general kernel support for memory encryption
Changes to the existing page table macros will allow the SME support to be enabled in a simple fashion with minimal changes to files that use these macros. Since the memory encryption mask will now be part of the regular pagetable macros, we introduce two new macros (_PAGE_TABLE_NOENC and _KERNPG_TABLE_NOENC) to allow for early pagetable creation/initialization without the encryption mask before SME becomes active. Two new pgprot() macros are defined to allow setting or clearing the page encryption mask. The FIXMAP_PAGE_NOCACHE define is introduced for use with MMIO. SME does not support encryption for MMIO areas so this define removes the encryption mask from the page attribute. Two new macros are introduced (__sme_pa() / __sme_pa_nodebug()) to allow creating a physical address with the encryption mask. These are used when working with the cr3 register so that the PGD can be encrypted. The current __va() macro is updated so that the virtual address is generated based off of the physical address without the encryption mask thus allowing the same virtual address to be generated regardless of whether encryption is enabled for that physical location or not. Also, an early initialization function is added for SME. If SME is active, this function: - Updates the early_pmd_flags so that early page faults create mappings with the encryption mask. - Updates the __supported_pte_mask to include the encryption mask. - Updates the protection_map entries to include the encryption mask so that user-space allocations will automatically have the encryption mask applied. 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/b36e952c4c39767ae7f0a41cf5345adf27438480.1500319216.git.thomas.lendacky@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/mm/pageattr.c')
-rw-r--r--arch/x86/mm/pageattr.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 757b0bcdf712..7e2d6c0a64c4 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -2020,6 +2020,9 @@ int kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address,
if (!(page_flags & _PAGE_RW))
cpa.mask_clr = __pgprot(_PAGE_RW);
+ if (!(page_flags & _PAGE_ENC))
+ cpa.mask_clr = pgprot_encrypted(cpa.mask_clr);
+
cpa.mask_set = __pgprot(_PAGE_PRESENT | page_flags);
retval = __change_page_attr_set_clr(&cpa, 0);