diff options
Diffstat (limited to 'arch/x86/kernel/machine_kexec_64.c')
| -rw-r--r-- | arch/x86/kernel/machine_kexec_64.c | 122 |
1 files changed, 116 insertions, 6 deletions
diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c index ceba408ea982..5dcd438ad8f2 100644 --- a/arch/x86/kernel/machine_kexec_64.c +++ b/arch/x86/kernel/machine_kexec_64.c @@ -1,9 +1,7 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * handle transition of Linux booting another kernel * Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com> - * - * This source code is licensed under the GNU General Public License, - * Version 2. See the file COPYING for more details. */ #define pr_fmt(fmt) "kexec: " fmt @@ -18,6 +16,7 @@ #include <linux/io.h> #include <linux/suspend.h> #include <linux/vmalloc.h> +#include <linux/efi.h> #include <asm/init.h> #include <asm/pgtable.h> @@ -29,6 +28,55 @@ #include <asm/setup.h> #include <asm/set_memory.h> +#ifdef CONFIG_ACPI +/* + * Used while adding mapping for ACPI tables. + * Can be reused when other iomem regions need be mapped + */ +struct init_pgtable_data { + struct x86_mapping_info *info; + pgd_t *level4p; +}; + +static int mem_region_callback(struct resource *res, void *arg) +{ + struct init_pgtable_data *data = arg; + unsigned long mstart, mend; + + mstart = res->start; + mend = mstart + resource_size(res) - 1; + + return kernel_ident_mapping_init(data->info, data->level4p, mstart, mend); +} + +static int +map_acpi_tables(struct x86_mapping_info *info, pgd_t *level4p) +{ + struct init_pgtable_data data; + unsigned long flags; + int ret; + + data.info = info; + data.level4p = level4p; + flags = IORESOURCE_MEM | IORESOURCE_BUSY; + + ret = walk_iomem_res_desc(IORES_DESC_ACPI_TABLES, flags, 0, -1, + &data, mem_region_callback); + if (ret && ret != -EINVAL) + return ret; + + /* ACPI tables could be located in ACPI Non-volatile Storage region */ + ret = walk_iomem_res_desc(IORES_DESC_ACPI_NV_STORAGE, flags, 0, -1, + &data, mem_region_callback); + if (ret && ret != -EINVAL) + return ret; + + return 0; +} +#else +static int map_acpi_tables(struct x86_mapping_info *info, pgd_t *level4p) { return 0; } +#endif + #ifdef CONFIG_KEXEC_FILE const struct kexec_file_ops * const kexec_file_loaders[] = { &kexec_bzImage64_ops, @@ -36,6 +84,31 @@ const struct kexec_file_ops * const kexec_file_loaders[] = { }; #endif +static int +map_efi_systab(struct x86_mapping_info *info, pgd_t *level4p) +{ +#ifdef CONFIG_EFI + unsigned long mstart, mend; + + if (!efi_enabled(EFI_BOOT)) + return 0; + + mstart = (boot_params.efi_info.efi_systab | + ((u64)boot_params.efi_info.efi_systab_hi<<32)); + + if (efi_enabled(EFI_64BIT)) + mend = mstart + sizeof(efi_system_table_64_t); + else + mend = mstart + sizeof(efi_system_table_32_t); + + if (!mstart) + return 0; + + return kernel_ident_mapping_init(info, level4p, mstart, mend); +#endif + return 0; +} + static void free_transition_pgtable(struct kimage *image) { free_page((unsigned long)image->arch.p4d); @@ -50,12 +123,13 @@ static void free_transition_pgtable(struct kimage *image) static int init_transition_pgtable(struct kimage *image, pgd_t *pgd) { + pgprot_t prot = PAGE_KERNEL_EXEC_NOENC; + unsigned long vaddr, paddr; + int result = -ENOMEM; p4d_t *p4d; pud_t *pud; pmd_t *pmd; pte_t *pte; - unsigned long vaddr, paddr; - int result = -ENOMEM; vaddr = (unsigned long)relocate_kernel; paddr = __pa(page_address(image->control_code_page)+PAGE_SIZE); @@ -92,7 +166,11 @@ static int init_transition_pgtable(struct kimage *image, pgd_t *pgd) set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE)); } pte = pte_offset_kernel(pmd, vaddr); - set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL_EXEC_NOENC)); + + if (sev_active()) + prot = PAGE_KERNEL_EXEC; + + set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, prot)); return 0; err: return result; @@ -129,6 +207,11 @@ static int init_pgtable(struct kimage *image, unsigned long start_pgtable) level4p = (pgd_t *)__va(start_pgtable); clear_page(level4p); + if (sev_active()) { + info.page_flag |= _PAGE_ENC; + info.kernpg_flag |= _PAGE_ENC; + } + if (direct_gbpages) info.direct_gbpages = true; @@ -159,6 +242,18 @@ static int init_pgtable(struct kimage *image, unsigned long start_pgtable) return result; } + /* + * Prepare EFI systab and ACPI tables for kexec kernel since they are + * not covered by pfn_mapped. + */ + result = map_efi_systab(&info, level4p); + if (result) + return result; + + result = map_acpi_tables(&info, level4p); + if (result) + return result; + return init_transition_pgtable(image, level4p); } @@ -559,8 +654,20 @@ void arch_kexec_unprotect_crashkres(void) kexec_mark_crashkres(false); } +/* + * During a traditional boot under SME, SME will encrypt the kernel, + * so the SME kexec kernel also needs to be un-encrypted in order to + * replicate a normal SME boot. + * + * During a traditional boot under SEV, the kernel has already been + * loaded encrypted, so the SEV kexec kernel needs to be encrypted in + * order to replicate a normal SEV boot. + */ int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp) { + if (sev_active()) + return 0; + /* * If SME is active we need to be sure that kexec pages are * not encrypted because when we boot to the new kernel the @@ -571,6 +678,9 @@ int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp) void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages) { + if (sev_active()) + return; + /* * If SME is active we need to reset the pages back to being * an encrypted mapping before freeing them. |