From 21729f81ce8ae76a6995681d40e16f7ce8075db4 Mon Sep 17 00:00:00 2001 From: Tom Lendacky Date: Mon, 17 Jul 2017 16:10:07 -0500 Subject: x86/mm: Provide general kernel support for memory encryption MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Thomas Gleixner Reviewed-by: Borislav Petkov Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Brijesh Singh Cc: Dave Young Cc: Dmitry Vyukov Cc: Jonathan Corbet Cc: Konrad Rzeszutek Wilk Cc: Larry Woodman Cc: Linus Torvalds Cc: Matt Fleming Cc: Michael S. Tsirkin Cc: Paolo Bonzini Cc: Peter Zijlstra Cc: Radim Krčmář Cc: Rik van Riel Cc: Toshimitsu Kani 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 --- arch/x86/include/asm/fixmap.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'arch/x86/include/asm/fixmap.h') diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h index b65155cc3760..d9ff226cb489 100644 --- a/arch/x86/include/asm/fixmap.h +++ b/arch/x86/include/asm/fixmap.h @@ -157,6 +157,13 @@ static inline void __set_fixmap(enum fixed_addresses idx, } #endif +/* + * FIXMAP_PAGE_NOCACHE is used for MMIO. Memory encryption is not + * supported for MMIO addresses, so make sure that the memory encryption + * mask is not part of the page attributes. + */ +#define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_IO_NOCACHE + #include #define __late_set_fixmap(idx, phys, flags) __set_fixmap(idx, phys, flags) -- cgit v1.2.1