diff options
Diffstat (limited to 'arch/x86/kernel/head64.c')
| -rw-r--r-- | arch/x86/kernel/head64.c | 101 |
1 files changed, 80 insertions, 21 deletions
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 9ba79543d9ee..bab4fa579450 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> @@ -33,7 +34,6 @@ /* * Manage page tables very early on. */ -extern pgd_t early_top_pgt[PTRS_PER_PGD]; extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD]; static unsigned int __initdata next_early_pgt; pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX); @@ -45,9 +45,11 @@ 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, + struct boot_params *bp) { unsigned long load_delta, *p; + unsigned long pgtable_flags; pgdval_t *pgd; p4dval_t *p4d; pudval_t *pud; @@ -69,6 +71,12 @@ 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(bp); + + /* 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); @@ -92,31 +100,35 @@ void __head __startup_64(unsigned long physaddr) * creates a bunch of nonsense entries but that is fine -- * it avoids problems around wraparound. */ + next_pgt_ptr = fixup_pointer(&next_early_pgt, physaddr); pud = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++], physaddr); pmd = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++], physaddr); + pgtable_flags = _KERNPG_TABLE_NOENC + 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++) { @@ -137,9 +149,30 @@ 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 */ @@ -147,17 +180,17 @@ static void __init reset_early_page_tables(void) { memset(early_top_pgt, 0, sizeof(pgd_t)*(PTRS_PER_PGD-1)); next_early_pgt = 0; - write_cr3(__pa_nodebug(early_top_pgt)); + write_cr3(__sme_pa_nodebug(early_top_pgt)); } /* Create a new PMD entry */ -int __init early_make_pgtable(unsigned long address) +int __init __early_make_pgtable(unsigned long address, pmdval_t pmd) { unsigned long physaddr = address - __PAGE_OFFSET; pgdval_t pgd, *pgd_p; p4dval_t p4d, *p4d_p; pudval_t pud, *pud_p; - pmdval_t pmd, *pmd_p; + pmdval_t *pmd_p; /* Invalid address or early pgt is done ? */ if (physaddr >= MAXMEM || read_cr3_pa() != __pa_nodebug(early_top_pgt)) @@ -216,12 +249,21 @@ again: memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD); *pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE; } - pmd = (physaddr & PMD_MASK) + early_pmd_flags; pmd_p[pmd_index(address)] = pmd; return 0; } +int __init early_make_pgtable(unsigned long address) +{ + unsigned long physaddr = address - __PAGE_OFFSET; + pmdval_t pmd; + + pmd = (physaddr & PMD_MASK) + early_pmd_flags; + + return __early_make_pgtable(address, pmd); +} + /* Don't add a printk in there. printk relies on the PDA which is not initialized yet. */ static void __init clear_bss(void) @@ -244,6 +286,12 @@ static void __init copy_bootdata(char *real_mode_data) char * command_line; unsigned long cmd_line_ptr; + /* + * If SME is active, this will create decrypted mappings of the + * boot data in advance of the copy operations. + */ + sme_map_bootdata(real_mode_data); + memcpy(&boot_params, real_mode_data, sizeof boot_params); sanitize_boot_params(&boot_params); cmd_line_ptr = get_cmd_line_ptr(); @@ -251,12 +299,18 @@ static void __init copy_bootdata(char *real_mode_data) command_line = __va(cmd_line_ptr); memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE); } + + /* + * The old boot data is no longer needed and won't be reserved, + * freeing up that memory for use by the system. If SME is active, + * we need to remove the mappings that were created so that the + * memory doesn't remain mapped as decrypted. + */ + sme_unmap_bootdata(real_mode_data); } asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data) { - int i; - /* * Build-time sanity checks on the kernel image and module * area mappings. (these are purely build-time and produce no code) @@ -280,11 +334,16 @@ asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data) clear_page(init_top_pgt); + /* + * SME support may update early_pmd_flags to include the memory + * encryption mask, so it needs to be called before anything + * that may generate a page fault. + */ + sme_early_init(); + kasan_early_init(); - for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) - set_intr_gate(i, early_idt_handler_array[i]); - load_idt((const struct desc_ptr *)&idt_descr); + idt_setup_early_handler(); copy_bootdata(__va(real_mode_data)); |