From: Suzuki K Poulose <suzuki.poulose@arm.com> mainline inclusion from mainline-v6.13-rc1 commit 42be24a4178fe51e6f47d91d8621b2f53820f88b category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IBWQ24 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Use the memory encryption APIs to trigger a RSI call to request a transition between protected memory and shared memory (or vice versa) and updating the kernel's linear map of modified pages to flip the top bit of the IPA. This requires that block mappings are not used in the direct map for realm guests. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Co-developed-by: Steven Price <steven.price@arm.com> Signed-off-by: Steven Price <steven.price@arm.com> Link: https://lore.kernel.org/r/20241017131434.40935-10-steven.price@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Conflicts: arch/arm64/Kconfig [Only context conflicts] Signed-off-by: Cai Xinchen <caixinchen1@huawei.com> --- arch/arm64/Kconfig | 3 + arch/arm64/include/asm/mem_encrypt.h | 9 +++ arch/arm64/include/asm/pgtable.h | 5 ++ arch/arm64/include/asm/set_memory.h | 3 + arch/arm64/kernel/rsi.c | 16 +++++ arch/arm64/mm/pageattr.c | 90 +++++++++++++++++++++++++++- 6 files changed, 123 insertions(+), 3 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index ced1c898f479..5422d1502fd6 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -20,6 +20,7 @@ config ARM64 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE select ARCH_HAS_CACHE_LINE_SIZE + select ARCH_HAS_CC_PLATFORM select ARCH_HAS_COPY_MC if ACPI_APEI_GHES select ARCH_HAS_CURRENT_STACK_POINTER select ARCH_HAS_DEBUG_VIRTUAL @@ -45,6 +46,8 @@ config ARM64 select ARCH_HAS_SETUP_DMA_OPS select ARCH_HAS_SET_DIRECT_MAP select ARCH_HAS_SET_MEMORY + select ARCH_HAS_MEM_ENCRYPT + select ARCH_HAS_FORCE_DMA_UNENCRYPTED select ARCH_STACKWALK select ARCH_HAS_STRICT_KERNEL_RWX select ARCH_HAS_STRICT_MODULE_RWX diff --git a/arch/arm64/include/asm/mem_encrypt.h b/arch/arm64/include/asm/mem_encrypt.h index b0c9a86b13a4..f8f78f622dd2 100644 --- a/arch/arm64/include/asm/mem_encrypt.h +++ b/arch/arm64/include/asm/mem_encrypt.h @@ -2,6 +2,8 @@ #ifndef __ASM_MEM_ENCRYPT_H #define __ASM_MEM_ENCRYPT_H +#include <asm/rsi.h> + struct arm64_mem_crypt_ops { int (*encrypt)(unsigned long addr, int numpages); int (*decrypt)(unsigned long addr, int numpages); @@ -12,4 +14,11 @@ int arm64_mem_crypt_ops_register(const struct arm64_mem_crypt_ops *ops); int set_memory_encrypted(unsigned long addr, int numpages); int set_memory_decrypted(unsigned long addr, int numpages); +int realm_register_memory_enc_ops(void); + +static inline bool force_dma_unencrypted(struct device *dev) +{ + return is_realm_world(); +} + #endif /* __ASM_MEM_ENCRYPT_H */ diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index b7f025ba7f72..626e43967e0a 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -568,6 +568,11 @@ static inline void set_pud_at(struct mm_struct *mm, unsigned long addr, #define pgprot_nx(prot) \ __pgprot_modify(prot, PTE_MAYBE_GP, PTE_PXN) +#define pgprot_decrypted(prot) \ + __pgprot_modify(prot, PROT_NS_SHARED, PROT_NS_SHARED) +#define pgprot_encrypted(prot) \ + __pgprot_modify(prot, PROT_NS_SHARED, 0) + /* * Mark the prot value as uncacheable and unbufferable. */ diff --git a/arch/arm64/include/asm/set_memory.h b/arch/arm64/include/asm/set_memory.h index 2a13bdc90a95..c859602c9af7 100644 --- a/arch/arm64/include/asm/set_memory.h +++ b/arch/arm64/include/asm/set_memory.h @@ -16,4 +16,7 @@ int set_direct_map_invalid_noflush(struct page *page); int set_direct_map_default_noflush(struct page *page); bool kernel_page_present(struct page *page); +int set_memory_encrypted(unsigned long addr, int numpages); +int set_memory_decrypted(unsigned long addr, int numpages); + #endif /* _ASM_ARM64_SET_MEMORY_H */ diff --git a/arch/arm64/kernel/rsi.c b/arch/arm64/kernel/rsi.c index a23c0a7154d2..3031f25c32ef 100644 --- a/arch/arm64/kernel/rsi.c +++ b/arch/arm64/kernel/rsi.c @@ -7,8 +7,10 @@ #include <linux/memblock.h> #include <linux/psci.h> #include <linux/swiotlb.h> +#include <linux/cc_platform.h> #include <asm/io.h> +#include <asm/mem_encrypt.h> #include <asm/rsi.h> static struct realm_config config; @@ -19,6 +21,17 @@ EXPORT_SYMBOL(prot_ns_shared); DEFINE_STATIC_KEY_FALSE_RO(rsi_present); EXPORT_SYMBOL(rsi_present); +bool cc_platform_has(enum cc_attr attr) +{ + switch (attr) { + case CC_ATTR_MEM_ENCRYPT: + return is_realm_world(); + default: + return false; + } +} +EXPORT_SYMBOL_GPL(cc_platform_has); + static bool rsi_version_matches(void) { unsigned long ver_lower, ver_higher; @@ -119,6 +132,9 @@ void __init arm64_rsi_init(void) if (arm64_ioremap_prot_hook_register(realm_ioremap_hook)) return; + if (realm_register_memory_enc_ops()) + return; + arm64_rsi_setup_memory(); static_branch_enable(&rsi_present); diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c index 6523161b4825..7ca69627ae29 100644 --- a/arch/arm64/mm/pageattr.c +++ b/arch/arm64/mm/pageattr.c @@ -5,10 +5,12 @@ #include <linux/kernel.h> #include <linux/mm.h> #include <linux/module.h> +#include <linux/mem_encrypt.h> #include <linux/sched.h> #include <linux/vmalloc.h> #include <asm/cacheflush.h> +#include <asm/pgtable-prot.h> #include <asm/set_memory.h> #include <asm/tlbflush.h> #include <asm/kfence.h> @@ -23,14 +25,16 @@ bool rodata_full __ro_after_init = IS_ENABLED(CONFIG_RODATA_FULL_DEFAULT_ENABLED bool can_set_direct_map(void) { /* - * rodata_full and DEBUG_PAGEALLOC require linear map to be - * mapped at page granularity, so that it is possible to + * rodata_full, DEBUG_PAGEALLOC and a Realm guest all require linear + * map to be mapped at page granularity, so that it is possible to * protect/unprotect single pages. * * KFENCE pool requires page-granular mapping if initialized late. + * + * Realms need to make pages shared/protected at page granularity. */ return rodata_full || debug_pagealloc_enabled() || - arm64_kfence_can_set_direct_map(); + arm64_kfence_can_set_direct_map() || is_realm_world(); } static int change_page_range(pte_t *ptep, unsigned long addr, void *data) @@ -198,6 +202,86 @@ int set_direct_map_default_noflush(struct page *page) PAGE_SIZE, change_page_range, &data); } +static int __set_memory_enc_dec(unsigned long addr, + int numpages, + bool encrypt) +{ + unsigned long set_prot = 0, clear_prot = 0; + phys_addr_t start, end; + int ret; + + if (!is_realm_world()) + return 0; + + if (!__is_lm_address(addr)) + return -EINVAL; + + start = __virt_to_phys(addr); + end = start + numpages * PAGE_SIZE; + + if (encrypt) + clear_prot = PROT_NS_SHARED; + else + set_prot = PROT_NS_SHARED; + + /* + * Break the mapping before we make any changes to avoid stale TLB + * entries or Synchronous External Aborts caused by RIPAS_EMPTY + */ + ret = __change_memory_common(addr, PAGE_SIZE * numpages, + __pgprot(set_prot), + __pgprot(clear_prot | PTE_VALID)); + + if (ret) + return ret; + + if (encrypt) + ret = rsi_set_memory_range_protected(start, end); + else + ret = rsi_set_memory_range_shared(start, end); + + if (ret) + return ret; + + return __change_memory_common(addr, PAGE_SIZE * numpages, + __pgprot(PTE_VALID), + __pgprot(0)); +} + +static int realm_set_memory_encrypted(unsigned long addr, int numpages) +{ + int ret = __set_memory_enc_dec(addr, numpages, true); + + /* + * If the request to change state fails, then the only sensible cause + * of action for the caller is to leak the memory + */ + WARN(ret, "Failed to encrypt memory, %d pages will be leaked", + numpages); + + return ret; +} + +static int realm_set_memory_decrypted(unsigned long addr, int numpages) +{ + int ret = __set_memory_enc_dec(addr, numpages, false); + + WARN(ret, "Failed to decrypt memory, %d pages will be leaked", + numpages); + + return ret; +} + +static const struct arm64_mem_crypt_ops realm_crypt_ops = { + .encrypt = realm_set_memory_encrypted, + .decrypt = realm_set_memory_decrypted, +}; + +int realm_register_memory_enc_ops(void) +{ + return arm64_mem_crypt_ops_register(&realm_crypt_ops); +} + #ifdef CONFIG_DEBUG_PAGEALLOC void __kernel_map_pages(struct page *page, int numpages, int enable) { -- 2.18.0.huawei.25