diff options
| -rw-r--r-- | arch/x86/include/asm/mem_encrypt.h | 8 | ||||
| -rw-r--r-- | arch/x86/kernel/head64.c | 53 | ||||
| -rw-r--r-- | arch/x86/kernel/head_64.S | 20 | ||||
| -rw-r--r-- | arch/x86/mm/mem_encrypt.c | 9 | ||||
| -rw-r--r-- | include/linux/mem_encrypt.h | 5 |
5 files changed, 82 insertions, 13 deletions
diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h index a1057961ac46..475e34f53793 100644 --- a/arch/x86/include/asm/mem_encrypt.h +++ b/arch/x86/include/asm/mem_encrypt.h @@ -15,14 +15,22 @@ #ifndef __ASSEMBLY__ +#include <linux/init.h> + #ifdef CONFIG_AMD_MEM_ENCRYPT extern unsigned long sme_me_mask; +void __init sme_encrypt_kernel(void); +void __init sme_enable(void); + #else /* !CONFIG_AMD_MEM_ENCRYPT */ #define sme_me_mask 0UL +static inline void __init sme_encrypt_kernel(void) { } +static inline void __init sme_enable(void) { } + #endif /* CONFIG_AMD_MEM_ENCRYPT */ #endif /* __ASSEMBLY__ */ diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 46c3c73e7f43..1f0ddcc9675c 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -14,6 +14,7 @@ #include <linux/start_kernel.h> #include <linux/io.h> #include <linux/memblock.h> +#include <linux/mem_encrypt.h> #include <asm/processor.h> #include <asm/proto.h> @@ -45,9 +46,10 @@ static void __head *fixup_pointer(void *ptr, unsigned long physaddr) return ptr - (void *)_text + (void *)physaddr; } -void __head __startup_64(unsigned long physaddr) +unsigned long __head __startup_64(unsigned long physaddr) { unsigned long load_delta, *p; + unsigned long pgtable_flags; pgdval_t *pgd; p4dval_t *p4d; pudval_t *pud; @@ -68,6 +70,12 @@ void __head __startup_64(unsigned long physaddr) if (load_delta & ~PMD_PAGE_MASK) for (;;); + /* Activate Secure Memory Encryption (SME) if supported and enabled */ + sme_enable(); + + /* Include the SME encryption mask in the fixup value */ + load_delta += sme_get_me_mask(); + /* Fixup the physical addresses in the page table */ pgd = fixup_pointer(&early_top_pgt, physaddr); @@ -94,28 +102,30 @@ void __head __startup_64(unsigned long physaddr) pud = fixup_pointer(early_dynamic_pgts[next_early_pgt++], physaddr); pmd = fixup_pointer(early_dynamic_pgts[next_early_pgt++], physaddr); + pgtable_flags = _KERNPG_TABLE + sme_get_me_mask(); if (IS_ENABLED(CONFIG_X86_5LEVEL)) { p4d = fixup_pointer(early_dynamic_pgts[next_early_pgt++], physaddr); i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD; - pgd[i + 0] = (pgdval_t)p4d + _KERNPG_TABLE; - pgd[i + 1] = (pgdval_t)p4d + _KERNPG_TABLE; + pgd[i + 0] = (pgdval_t)p4d + pgtable_flags; + pgd[i + 1] = (pgdval_t)p4d + pgtable_flags; i = (physaddr >> P4D_SHIFT) % PTRS_PER_P4D; - p4d[i + 0] = (pgdval_t)pud + _KERNPG_TABLE; - p4d[i + 1] = (pgdval_t)pud + _KERNPG_TABLE; + p4d[i + 0] = (pgdval_t)pud + pgtable_flags; + p4d[i + 1] = (pgdval_t)pud + pgtable_flags; } else { i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD; - pgd[i + 0] = (pgdval_t)pud + _KERNPG_TABLE; - pgd[i + 1] = (pgdval_t)pud + _KERNPG_TABLE; + pgd[i + 0] = (pgdval_t)pud + pgtable_flags; + pgd[i + 1] = (pgdval_t)pud + pgtable_flags; } i = (physaddr >> PUD_SHIFT) % PTRS_PER_PUD; - pud[i + 0] = (pudval_t)pmd + _KERNPG_TABLE; - pud[i + 1] = (pudval_t)pmd + _KERNPG_TABLE; + pud[i + 0] = (pudval_t)pmd + pgtable_flags; + pud[i + 1] = (pudval_t)pmd + pgtable_flags; pmd_entry = __PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL; + pmd_entry += sme_get_me_mask(); pmd_entry += physaddr; for (i = 0; i < DIV_ROUND_UP(_end - _text, PMD_SIZE); i++) { @@ -136,9 +146,30 @@ void __head __startup_64(unsigned long physaddr) pmd[i] += load_delta; } - /* Fixup phys_base */ + /* + * Fixup phys_base - remove the memory encryption mask to obtain + * the true physical address. + */ p = fixup_pointer(&phys_base, physaddr); - *p += load_delta; + *p += load_delta - sme_get_me_mask(); + + /* Encrypt the kernel (if SME is active) */ + sme_encrypt_kernel(); + + /* + * Return the SME encryption mask (if SME is active) to be used as a + * modifier for the initial pgdir entry programmed into CR3. + */ + return sme_get_me_mask(); +} + +unsigned long __startup_secondary_64(void) +{ + /* + * Return the SME encryption mask (if SME is active) to be used as a + * modifier for the initial pgdir entry programmed into CR3. + */ + return sme_get_me_mask(); } /* Wipe all early page tables except for the kernel symbol map */ diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 6225550883df..ec5d5e90c8f1 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -73,12 +73,19 @@ startup_64: /* Sanitize CPU configuration */ call verify_cpu + /* + * Perform pagetable fixups. Additionally, if SME is active, encrypt + * the kernel and retrieve the modifier (SME encryption mask if SME + * is active) to be added to the initial pgdir entry that will be + * programmed into CR3. + */ leaq _text(%rip), %rdi pushq %rsi call __startup_64 popq %rsi - movq $(early_top_pgt - __START_KERNEL_map), %rax + /* Form the CR3 value being sure to include the CR3 modifier */ + addq $(early_top_pgt - __START_KERNEL_map), %rax jmp 1f ENTRY(secondary_startup_64) /* @@ -98,7 +105,16 @@ ENTRY(secondary_startup_64) /* Sanitize CPU configuration */ call verify_cpu - movq $(init_top_pgt - __START_KERNEL_map), %rax + /* + * Retrieve the modifier (SME encryption mask if SME is active) to be + * added to the initial pgdir entry that will be programmed into CR3. + */ + pushq %rsi + call __startup_secondary_64 + popq %rsi + + /* Form the CR3 value being sure to include the CR3 modifier */ + addq $(init_top_pgt - __START_KERNEL_map), %rax 1: /* Enable PAE mode, PGE and LA57 */ diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c index b99d469c73e7..3ac6f99b095c 100644 --- a/arch/x86/mm/mem_encrypt.c +++ b/arch/x86/mm/mem_encrypt.c @@ -11,6 +11,7 @@ */ #include <linux/linkage.h> +#include <linux/init.h> /* * Since SME related variables are set early in the boot process they must @@ -19,3 +20,11 @@ */ unsigned long sme_me_mask __section(.data) = 0; EXPORT_SYMBOL_GPL(sme_me_mask); + +void __init sme_encrypt_kernel(void) +{ +} + +void __init sme_enable(void) +{ +} diff --git a/include/linux/mem_encrypt.h b/include/linux/mem_encrypt.h index 59769f7287e4..570f4fcff13f 100644 --- a/include/linux/mem_encrypt.h +++ b/include/linux/mem_encrypt.h @@ -30,6 +30,11 @@ static inline bool sme_active(void) return !!sme_me_mask; } +static inline unsigned long sme_get_me_mask(void) +{ + return sme_me_mask; +} + #endif /* __ASSEMBLY__ */ #endif /* __MEM_ENCRYPT_H__ */ |