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 --- include/asm-generic/pgtable.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'include/asm-generic') diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 7dfa767dc680..4d7bb98f4134 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -582,6 +582,18 @@ static inline void ptep_modify_prot_commit(struct mm_struct *mm, #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */ #endif /* CONFIG_MMU */ +/* + * No-op macros that just return the current protection value. Defined here + * because these macros can be used used even if CONFIG_MMU is not defined. + */ +#ifndef pgprot_encrypted +#define pgprot_encrypted(prot) (prot) +#endif + +#ifndef pgprot_decrypted +#define pgprot_decrypted(prot) (prot) +#endif + /* * A facility to provide lazy MMU batching. This allows PTE updates and * page invalidations to be delayed until a call to leave lazy MMU mode -- cgit v1.2.3 From f88a68facd9a15b94f8c195d9d2c0b30c76c595a Mon Sep 17 00:00:00 2001 From: Tom Lendacky Date: Mon, 17 Jul 2017 16:10:09 -0500 Subject: x86/mm: Extend early_memremap() support with additional attrs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add early_memremap() support to be able to specify encrypted and decrypted mappings with and without write-protection. The use of write-protection is necessary when encrypting data "in place". The write-protect attribute is considered cacheable for loads, but not stores. This implies that the hardware will never give the core a dirty line with this memtype. 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/479b5832c30fae3efa7932e48f81794e86397229.1500319216.git.thomas.lendacky@amd.com Signed-off-by: Ingo Molnar --- arch/x86/Kconfig | 4 ++++ arch/x86/include/asm/fixmap.h | 13 +++++++++++ arch/x86/include/asm/pgtable_types.h | 8 +++++++ arch/x86/mm/ioremap.c | 44 ++++++++++++++++++++++++++++++++++++ include/asm-generic/early_ioremap.h | 2 ++ mm/early_ioremap.c | 10 ++++++++ 6 files changed, 81 insertions(+) (limited to 'include/asm-generic') diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index ba7b93d08d00..8328bcb9ce8b 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1440,6 +1440,10 @@ config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT If set to N, then the encryption of system memory can be activated with the mem_encrypt=on command line option. +config ARCH_USE_MEMREMAP_PROT + def_bool y + depends on AMD_MEM_ENCRYPT + # Common NUMA Features config NUMA bool "Numa Memory Allocation and Scheduler Support" diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h index d9ff226cb489..dcd9fb55e679 100644 --- a/arch/x86/include/asm/fixmap.h +++ b/arch/x86/include/asm/fixmap.h @@ -164,6 +164,19 @@ static inline void __set_fixmap(enum fixed_addresses idx, */ #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_IO_NOCACHE +/* + * Early memremap routines used for in-place encryption. The mappings created + * by these routines are intended to be used as temporary mappings. + */ +void __init *early_memremap_encrypted(resource_size_t phys_addr, + unsigned long size); +void __init *early_memremap_encrypted_wp(resource_size_t phys_addr, + unsigned long size); +void __init *early_memremap_decrypted(resource_size_t phys_addr, + unsigned long size); +void __init *early_memremap_decrypted_wp(resource_size_t phys_addr, + unsigned long size); + #include #define __late_set_fixmap(idx, phys, flags) __set_fixmap(idx, phys, flags) diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index de32ca32928a..32095af0fefb 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -161,6 +161,7 @@ enum page_cache_mode { #define _PAGE_CACHE_MASK (_PAGE_PAT | _PAGE_PCD | _PAGE_PWT) #define _PAGE_NOCACHE (cachemode2protval(_PAGE_CACHE_MODE_UC)) +#define _PAGE_CACHE_WP (cachemode2protval(_PAGE_CACHE_MODE_WP)) #define PAGE_NONE __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED) #define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | \ @@ -189,6 +190,7 @@ enum page_cache_mode { #define __PAGE_KERNEL_VVAR (__PAGE_KERNEL_RO | _PAGE_USER) #define __PAGE_KERNEL_LARGE (__PAGE_KERNEL | _PAGE_PSE) #define __PAGE_KERNEL_LARGE_EXEC (__PAGE_KERNEL_EXEC | _PAGE_PSE) +#define __PAGE_KERNEL_WP (__PAGE_KERNEL | _PAGE_CACHE_WP) #define __PAGE_KERNEL_IO (__PAGE_KERNEL) #define __PAGE_KERNEL_IO_NOCACHE (__PAGE_KERNEL_NOCACHE) @@ -202,6 +204,12 @@ enum page_cache_mode { #define _KERNPG_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | \ _PAGE_DIRTY | _PAGE_ENC) +#define __PAGE_KERNEL_ENC (__PAGE_KERNEL | _PAGE_ENC) +#define __PAGE_KERNEL_ENC_WP (__PAGE_KERNEL_WP | _PAGE_ENC) + +#define __PAGE_KERNEL_NOENC (__PAGE_KERNEL) +#define __PAGE_KERNEL_NOENC_WP (__PAGE_KERNEL_WP) + #define PAGE_KERNEL __pgprot(__PAGE_KERNEL | _PAGE_ENC) #define PAGE_KERNEL_RO __pgprot(__PAGE_KERNEL_RO | _PAGE_ENC) #define PAGE_KERNEL_EXEC __pgprot(__PAGE_KERNEL_EXEC | _PAGE_ENC) diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 66ddf5e8ffc8..570201bbf442 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -417,6 +417,50 @@ void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr) iounmap((void __iomem *)((unsigned long)addr & PAGE_MASK)); } +#ifdef CONFIG_ARCH_USE_MEMREMAP_PROT +/* Remap memory with encryption */ +void __init *early_memremap_encrypted(resource_size_t phys_addr, + unsigned long size) +{ + return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_ENC); +} + +/* + * Remap memory with encryption and write-protected - cannot be called + * before pat_init() is called + */ +void __init *early_memremap_encrypted_wp(resource_size_t phys_addr, + unsigned long size) +{ + /* Be sure the write-protect PAT entry is set for write-protect */ + if (__pte2cachemode_tbl[_PAGE_CACHE_MODE_WP] != _PAGE_CACHE_MODE_WP) + return NULL; + + return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_ENC_WP); +} + +/* Remap memory without encryption */ +void __init *early_memremap_decrypted(resource_size_t phys_addr, + unsigned long size) +{ + return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_NOENC); +} + +/* + * Remap memory without encryption and write-protected - cannot be called + * before pat_init() is called + */ +void __init *early_memremap_decrypted_wp(resource_size_t phys_addr, + unsigned long size) +{ + /* Be sure the write-protect PAT entry is set for write-protect */ + if (__pte2cachemode_tbl[_PAGE_CACHE_MODE_WP] != _PAGE_CACHE_MODE_WP) + return NULL; + + return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_NOENC_WP); +} +#endif /* CONFIG_ARCH_USE_MEMREMAP_PROT */ + static pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)] __page_aligned_bss; static inline pmd_t * __init early_ioremap_pmd(unsigned long addr) diff --git a/include/asm-generic/early_ioremap.h b/include/asm-generic/early_ioremap.h index 734ad4db388c..2edef8d7fa6b 100644 --- a/include/asm-generic/early_ioremap.h +++ b/include/asm-generic/early_ioremap.h @@ -13,6 +13,8 @@ extern void *early_memremap(resource_size_t phys_addr, unsigned long size); extern void *early_memremap_ro(resource_size_t phys_addr, unsigned long size); +extern void *early_memremap_prot(resource_size_t phys_addr, + unsigned long size, unsigned long prot_val); extern void early_iounmap(void __iomem *addr, unsigned long size); extern void early_memunmap(void *addr, unsigned long size); diff --git a/mm/early_ioremap.c b/mm/early_ioremap.c index 6d5717bd7197..d7d30da754ba 100644 --- a/mm/early_ioremap.c +++ b/mm/early_ioremap.c @@ -226,6 +226,16 @@ early_memremap_ro(resource_size_t phys_addr, unsigned long size) } #endif +#ifdef CONFIG_ARCH_USE_MEMREMAP_PROT +void __init * +early_memremap_prot(resource_size_t phys_addr, unsigned long size, + unsigned long prot_val) +{ + return (__force void *)__early_ioremap(phys_addr, size, + __pgprot(prot_val)); +} +#endif + #define MAX_MAP_CHUNK (NR_FIX_BTMAPS << PAGE_SHIFT) void __init copy_from_early_mem(void *dest, phys_addr_t src, unsigned long size) -- cgit v1.2.3