diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/sections.h | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/crash.c | 6 | ||||
| -rw-r--r-- | arch/x86/kernel/e820.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/machine_kexec_64.c | 31 | ||||
| -rw-r--r-- | arch/x86/kernel/setup.c | 8 | ||||
| -rw-r--r-- | arch/x86/kernel/vmlinux.lds.S | 34 | ||||
| -rw-r--r-- | arch/x86/mm/ioremap.c | 71 | ||||
| -rw-r--r-- | arch/x86/mm/mem_encrypt_identity.c | 22 |
8 files changed, 142 insertions, 34 deletions
diff --git a/arch/x86/include/asm/sections.h b/arch/x86/include/asm/sections.h index 8ea1cfdbeabc..71b32f2570ab 100644 --- a/arch/x86/include/asm/sections.h +++ b/arch/x86/include/asm/sections.h @@ -13,4 +13,6 @@ extern char __end_rodata_aligned[]; extern char __end_rodata_hpage_align[]; #endif +extern char __end_of_kernel_reserve[]; + #endif /* _ASM_X86_SECTIONS_H */ diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index a55094b5f452..2bf70a2fed90 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -375,6 +375,12 @@ int crash_setup_memmap_entries(struct kimage *image, struct boot_params *params) walk_iomem_res_desc(IORES_DESC_ACPI_NV_STORAGE, flags, 0, -1, &cmd, memmap_entry_callback); + /* Add e820 reserved ranges */ + cmd.type = E820_TYPE_RESERVED; + flags = IORESOURCE_MEM; + walk_iomem_res_desc(IORES_DESC_RESERVED, flags, 0, -1, &cmd, + memmap_entry_callback); + /* Add crashk_low_res region */ if (crashk_low_res.end) { ei.addr = crashk_low_res.start; diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index 8f32e705a980..e69408bf664b 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -1063,10 +1063,10 @@ static unsigned long __init e820_type_to_iores_desc(struct e820_entry *entry) case E820_TYPE_NVS: return IORES_DESC_ACPI_NV_STORAGE; case E820_TYPE_PMEM: return IORES_DESC_PERSISTENT_MEMORY; case E820_TYPE_PRAM: return IORES_DESC_PERSISTENT_MEMORY_LEGACY; + case E820_TYPE_RESERVED: return IORES_DESC_RESERVED; case E820_TYPE_RESERVED_KERN: /* Fall-through: */ case E820_TYPE_RAM: /* Fall-through: */ case E820_TYPE_UNUSABLE: /* Fall-through: */ - case E820_TYPE_RESERVED: /* Fall-through: */ default: return IORES_DESC_NONE; } } diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c index 9184037aec62..5dcd438ad8f2 100644 --- a/arch/x86/kernel/machine_kexec_64.c +++ b/arch/x86/kernel/machine_kexec_64.c @@ -123,12 +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); @@ -165,7 +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; @@ -202,6 +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; @@ -644,8 +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 @@ -656,6 +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. diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index dcbdf54fb5c1..bbe35bf879f5 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -836,8 +836,14 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p) void __init setup_arch(char **cmdline_p) { + /* + * Reserve the memory occupied by the kernel between _text and + * __end_of_kernel_reserve symbols. Any kernel sections after the + * __end_of_kernel_reserve symbol must be explicitly reserved with a + * separate memblock_reserve() or they will be discarded. + */ memblock_reserve(__pa_symbol(_text), - (unsigned long)__bss_stop - (unsigned long)_text); + (unsigned long)__end_of_kernel_reserve - (unsigned long)_text); /* * Make sure page 0 is always reserved because on systems with diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 0850b5149345..147cd020516a 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -368,6 +368,14 @@ SECTIONS __bss_stop = .; } + /* + * The memory occupied from _text to here, __end_of_kernel_reserve, is + * automatically reserved in setup_arch(). Anything after here must be + * explicitly reserved using memblock_reserve() or it will be discarded + * and treated as available memory. + */ + __end_of_kernel_reserve = .; + . = ALIGN(PAGE_SIZE); .brk : AT(ADDR(.brk) - LOAD_OFFSET) { __brk_base = .; @@ -379,10 +387,34 @@ SECTIONS . = ALIGN(PAGE_SIZE); /* keep VO_INIT_SIZE page aligned */ _end = .; +#ifdef CONFIG_AMD_MEM_ENCRYPT + /* + * Early scratch/workarea section: Lives outside of the kernel proper + * (_text - _end). + * + * Resides after _end because even though the .brk section is after + * __end_of_kernel_reserve, the .brk section is later reserved as a + * part of the kernel. Since it is located after __end_of_kernel_reserve + * it will be discarded and become part of the available memory. As + * such, it can only be used by very early boot code and must not be + * needed afterwards. + * + * Currently used by SME for performing in-place encryption of the + * kernel during boot. Resides on a 2MB boundary to simplify the + * pagetable setup used for SME in-place encryption. + */ + . = ALIGN(HPAGE_SIZE); + .init.scratch : AT(ADDR(.init.scratch) - LOAD_OFFSET) { + __init_scratch_begin = .; + *(.init.scratch) + . = ALIGN(HPAGE_SIZE); + __init_scratch_end = .; + } +#endif + STABS_DEBUG DWARF_DEBUG - /* Sections to be discarded */ DISCARDS /DISCARD/ : { *(.eh_frame) diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 4b6423e7bd21..e500f1df1140 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -28,9 +28,11 @@ #include "physaddr.h" -struct ioremap_mem_flags { - bool system_ram; - bool desc_other; +/* + * Descriptor controlling ioremap() behavior. + */ +struct ioremap_desc { + unsigned int flags; }; /* @@ -62,13 +64,14 @@ int ioremap_change_attr(unsigned long vaddr, unsigned long size, return err; } -static bool __ioremap_check_ram(struct resource *res) +/* Does the range (or a subset of) contain normal RAM? */ +static unsigned int __ioremap_check_ram(struct resource *res) { unsigned long start_pfn, stop_pfn; unsigned long i; if ((res->flags & IORESOURCE_SYSTEM_RAM) != IORESOURCE_SYSTEM_RAM) - return false; + return 0; start_pfn = (res->start + PAGE_SIZE - 1) >> PAGE_SHIFT; stop_pfn = (res->end + 1) >> PAGE_SHIFT; @@ -76,28 +79,44 @@ static bool __ioremap_check_ram(struct resource *res) for (i = 0; i < (stop_pfn - start_pfn); ++i) if (pfn_valid(start_pfn + i) && !PageReserved(pfn_to_page(start_pfn + i))) - return true; + return IORES_MAP_SYSTEM_RAM; } - return false; + return 0; } -static int __ioremap_check_desc_other(struct resource *res) +/* + * In a SEV guest, NONE and RESERVED should not be mapped encrypted because + * there the whole memory is already encrypted. + */ +static unsigned int __ioremap_check_encrypted(struct resource *res) { - return (res->desc != IORES_DESC_NONE); + if (!sev_active()) + return 0; + + switch (res->desc) { + case IORES_DESC_NONE: + case IORES_DESC_RESERVED: + break; + default: + return IORES_MAP_ENCRYPTED; + } + + return 0; } -static int __ioremap_res_check(struct resource *res, void *arg) +static int __ioremap_collect_map_flags(struct resource *res, void *arg) { - struct ioremap_mem_flags *flags = arg; + struct ioremap_desc *desc = arg; - if (!flags->system_ram) - flags->system_ram = __ioremap_check_ram(res); + if (!(desc->flags & IORES_MAP_SYSTEM_RAM)) + desc->flags |= __ioremap_check_ram(res); - if (!flags->desc_other) - flags->desc_other = __ioremap_check_desc_other(res); + if (!(desc->flags & IORES_MAP_ENCRYPTED)) + desc->flags |= __ioremap_check_encrypted(res); - return flags->system_ram && flags->desc_other; + return ((desc->flags & (IORES_MAP_SYSTEM_RAM | IORES_MAP_ENCRYPTED)) == + (IORES_MAP_SYSTEM_RAM | IORES_MAP_ENCRYPTED)); } /* @@ -106,15 +125,15 @@ static int __ioremap_res_check(struct resource *res, void *arg) * resource described not as IORES_DESC_NONE (e.g. IORES_DESC_ACPI_TABLES). */ static void __ioremap_check_mem(resource_size_t addr, unsigned long size, - struct ioremap_mem_flags *flags) + struct ioremap_desc *desc) { u64 start, end; start = (u64)addr; end = start + size - 1; - memset(flags, 0, sizeof(*flags)); + memset(desc, 0, sizeof(struct ioremap_desc)); - walk_mem_res(start, end, flags, __ioremap_res_check); + walk_mem_res(start, end, desc, __ioremap_collect_map_flags); } /* @@ -131,15 +150,15 @@ static void __ioremap_check_mem(resource_size_t addr, unsigned long size, * have to convert them into an offset in a page-aligned mapping, but the * caller shouldn't need to know that small detail. */ -static void __iomem *__ioremap_caller(resource_size_t phys_addr, - unsigned long size, enum page_cache_mode pcm, - void *caller, bool encrypted) +static void __iomem * +__ioremap_caller(resource_size_t phys_addr, unsigned long size, + enum page_cache_mode pcm, void *caller, bool encrypted) { unsigned long offset, vaddr; resource_size_t last_addr; const resource_size_t unaligned_phys_addr = phys_addr; const unsigned long unaligned_size = size; - struct ioremap_mem_flags mem_flags; + struct ioremap_desc io_desc; struct vm_struct *area; enum page_cache_mode new_pcm; pgprot_t prot; @@ -158,12 +177,12 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, return NULL; } - __ioremap_check_mem(phys_addr, size, &mem_flags); + __ioremap_check_mem(phys_addr, size, &io_desc); /* * Don't allow anybody to remap normal RAM that we're using.. */ - if (mem_flags.system_ram) { + if (io_desc.flags & IORES_MAP_SYSTEM_RAM) { WARN_ONCE(1, "ioremap on RAM at %pa - %pa\n", &phys_addr, &last_addr); return NULL; @@ -201,7 +220,7 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, * resulting mapping. */ prot = PAGE_KERNEL_IO; - if ((sev_active() && mem_flags.desc_other) || encrypted) + if ((io_desc.flags & IORES_MAP_ENCRYPTED) || encrypted) prot = pgprot_encrypted(prot); switch (pcm) { diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c index dddcd2a1afdb..e2b0e2ac07bb 100644 --- a/arch/x86/mm/mem_encrypt_identity.c +++ b/arch/x86/mm/mem_encrypt_identity.c @@ -70,6 +70,19 @@ struct sme_populate_pgd_data { unsigned long vaddr_end; }; +/* + * This work area lives in the .init.scratch section, which lives outside of + * the kernel proper. It is sized to hold the intermediate copy buffer and + * more than enough pagetable pages. + * + * By using this section, the kernel can be encrypted in place and it + * avoids any possibility of boot parameters or initramfs images being + * placed such that the in-place encryption logic overwrites them. This + * section is 2MB aligned to allow for simple pagetable setup using only + * PMD entries (see vmlinux.lds.S). + */ +static char sme_workarea[2 * PMD_PAGE_SIZE] __section(.init.scratch); + static char sme_cmdline_arg[] __initdata = "mem_encrypt"; static char sme_cmdline_on[] __initdata = "on"; static char sme_cmdline_off[] __initdata = "off"; @@ -311,8 +324,13 @@ void __init sme_encrypt_kernel(struct boot_params *bp) } #endif - /* Set the encryption workarea to be immediately after the kernel */ - workarea_start = kernel_end; + /* + * We're running identity mapped, so we must obtain the address to the + * SME encryption workarea using rip-relative addressing. + */ + asm ("lea sme_workarea(%%rip), %0" + : "=r" (workarea_start) + : "p" (sme_workarea)); /* * Calculate required number of workarea bytes needed: |