diff options
44 files changed, 1448 insertions, 307 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index ee272423ec20..f9ae63863f94 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -887,9 +887,11 @@ config INTEL_TDX_GUEST bool "Intel TDX (Trust Domain Extensions) - Guest Support" depends on X86_64 && CPU_SUP_INTEL depends on X86_X2APIC + depends on EFI_STUB select ARCH_HAS_CC_PLATFORM select X86_MEM_ENCRYPT select X86_MCE + select UNACCEPTED_MEMORY help Support running as a guest under Intel TDX. Without this support, the guest kernel can not boot or run under TDX. @@ -1544,11 +1546,13 @@ config X86_MEM_ENCRYPT config AMD_MEM_ENCRYPT bool "AMD Secure Memory Encryption (SME) support" depends on X86_64 && CPU_SUP_AMD + depends on EFI_STUB select DMA_COHERENT_POOL select ARCH_USE_MEMREMAP_PROT select INSTRUCTION_DECODER select ARCH_HAS_CC_PLATFORM select X86_MEM_ENCRYPT + select UNACCEPTED_MEMORY help Say yes to enable support for the encryption of system memory. This requires an AMD processor that supports Secure Memory diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 0f78dbbbdcdd..40d2ff503079 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -106,7 +106,8 @@ ifdef CONFIG_X86_64 endif vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o -vmlinux-objs-$(CONFIG_INTEL_TDX_GUEST) += $(obj)/tdx.o $(obj)/tdcall.o +vmlinux-objs-$(CONFIG_INTEL_TDX_GUEST) += $(obj)/tdx.o $(obj)/tdcall.o $(obj)/tdx-shared.o +vmlinux-objs-$(CONFIG_UNACCEPTED_MEMORY) += $(obj)/mem.o vmlinux-objs-$(CONFIG_EFI) += $(obj)/efi.o vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_mixed.o diff --git a/arch/x86/boot/compressed/efi.h b/arch/x86/boot/compressed/efi.h index 7db2f41b54cd..866c0af8b5b9 100644 --- a/arch/x86/boot/compressed/efi.h +++ b/arch/x86/boot/compressed/efi.h @@ -16,6 +16,7 @@ typedef guid_t efi_guid_t __aligned(__alignof__(u32)); #define ACPI_TABLE_GUID EFI_GUID(0xeb9d2d30, 0x2d88, 0x11d3, 0x9a, 0x16, 0x00, 0x90, 0x27, 0x3f, 0xc1, 0x4d) #define ACPI_20_TABLE_GUID EFI_GUID(0x8868e871, 0xe4f1, 0x11d3, 0xbc, 0x22, 0x00, 0x80, 0xc7, 0x3c, 0x88, 0x81) #define EFI_CC_BLOB_GUID EFI_GUID(0x067b1f5f, 0xcf26, 0x44c5, 0x85, 0x54, 0x93, 0xd7, 0x77, 0x91, 0x2d, 0x42) +#define LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID EFI_GUID(0xd5d1de3c, 0x105c, 0x44f9, 0x9e, 0xa9, 0xbc, 0xef, 0x98, 0x12, 0x00, 0x31) #define EFI32_LOADER_SIGNATURE "EL32" #define EFI64_LOADER_SIGNATURE "EL64" @@ -32,6 +33,7 @@ typedef struct { } efi_table_hdr_t; #define EFI_CONVENTIONAL_MEMORY 7 +#define EFI_UNACCEPTED_MEMORY 15 #define EFI_MEMORY_MORE_RELIABLE \ ((u64)0x0000000000010000ULL) /* higher reliability */ @@ -104,6 +106,14 @@ struct efi_setup_data { u64 reserved[8]; }; +struct efi_unaccepted_memory { + u32 version; + u32 unit_size; + u64 phys_base; + u64 size; + unsigned long bitmap[]; +}; + static inline int efi_guidcmp (efi_guid_t left, efi_guid_t right) { return memcmp(&left, &right, sizeof (efi_guid_t)); diff --git a/arch/x86/boot/compressed/error.c b/arch/x86/boot/compressed/error.c index c881878e56d3..5313c5cb2b80 100644 --- a/arch/x86/boot/compressed/error.c +++ b/arch/x86/boot/compressed/error.c @@ -22,3 +22,22 @@ void error(char *m) while (1) asm("hlt"); } + +/* EFI libstub provides vsnprintf() */ +#ifdef CONFIG_EFI_STUB +void panic(const char *fmt, ...) +{ + static char buf[1024]; + va_list args; + int len; + + va_start(args, fmt); + len = vsnprintf(buf, sizeof(buf), fmt, args); + va_end(args); + + if (len && buf[len - 1] == '\n') + buf[len - 1] = '\0'; + + error(buf); +} +#endif diff --git a/arch/x86/boot/compressed/error.h b/arch/x86/boot/compressed/error.h index 1de5821184f1..86fe33b93715 100644 --- a/arch/x86/boot/compressed/error.h +++ b/arch/x86/boot/compressed/error.h @@ -6,5 +6,6 @@ void warn(char *m); void error(char *m) __noreturn; +void panic(const char *fmt, ...) __noreturn __cold; #endif /* BOOT_COMPRESSED_ERROR_H */ diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index 454757fbdfe5..9193acf0e9cd 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -672,6 +672,33 @@ static bool process_mem_region(struct mem_vector *region, } #ifdef CONFIG_EFI + +/* + * Only EFI_CONVENTIONAL_MEMORY and EFI_UNACCEPTED_MEMORY (if supported) are + * guaranteed to be free. + * + * Pick free memory more conservatively than the EFI spec allows: according to + * the spec, EFI_BOOT_SERVICES_{CODE|DATA} are also free memory and thus + * available to place the kernel image into, but in practice there's firmware + * where using that memory leads to crashes. Buggy vendor EFI code registers + * for an event that triggers on SetVirtualAddressMap(). The handler assumes + * that EFI_BOOT_SERVICES_DATA memory has not been touched by loader yet, which + * is probably true for Windows. + * + * Preserve EFI_BOOT_SERVICES_* regions until after SetVirtualAddressMap(). + */ +static inline bool memory_type_is_free(efi_memory_desc_t *md) +{ + if (md->type == EFI_CONVENTIONAL_MEMORY) + return true; + + if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) && + md->type == EFI_UNACCEPTED_MEMORY) + return true; + + return false; +} + /* * Returns true if we processed the EFI memmap, which we prefer over the E820 * table if it is available. @@ -716,18 +743,7 @@ process_efi_entries(unsigned long minimum, unsigned long image_size) for (i = 0; i < nr_desc; i++) { md = efi_early_memdesc_ptr(pmap, e->efi_memdesc_size, i); - /* - * Here we are more conservative in picking free memory than - * the EFI spec allows: - * - * According to the spec, EFI_BOOT_SERVICES_{CODE|DATA} are also - * free memory and thus available to place the kernel image into, - * but in practice there's firmware where using that memory leads - * to crashes. - * - * Only EFI_CONVENTIONAL_MEMORY is guaranteed to be free. - */ - if (md->type != EFI_CONVENTIONAL_MEMORY) + if (!memory_type_is_free(md)) continue; if (efi_soft_reserve_enabled() && diff --git a/arch/x86/boot/compressed/mem.c b/arch/x86/boot/compressed/mem.c new file mode 100644 index 000000000000..3c1609245f2a --- /dev/null +++ b/arch/x86/boot/compressed/mem.c @@ -0,0 +1,86 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include "error.h" +#include "misc.h" +#include "tdx.h" +#include "sev.h" +#include <asm/shared/tdx.h> + +/* + * accept_memory() and process_unaccepted_memory() called from EFI stub which + * runs before decompresser and its early_tdx_detect(). + * + * Enumerate TDX directly from the early users. + */ +static bool early_is_tdx_guest(void) +{ + static bool once; + static bool is_tdx; + + if (!IS_ENABLED(CONFIG_INTEL_TDX_GUEST)) + return false; + + if (!once) { + u32 eax, sig[3]; + + cpuid_count(TDX_CPUID_LEAF_ID, 0, &eax, + &sig[0], &sig[2], &sig[1]); + is_tdx = !memcmp(TDX_IDENT, sig, sizeof(sig)); + once = true; + } + + return is_tdx; +} + +void arch_accept_memory(phys_addr_t start, phys_addr_t end) +{ + /* Platform-specific memory-acceptance call goes here */ + if (early_is_tdx_guest()) { + if (!tdx_accept_memory(start, end)) + panic("TDX: Failed to accept memory\n"); + } else if (sev_snp_enabled()) { + snp_accept_memory(start, end); + } else { + error("Cannot accept memory: unknown platform\n"); + } +} + +bool init_unaccepted_memory(void) +{ + guid_t guid = LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID; + struct efi_unaccepted_memory *table; + unsigned long cfg_table_pa; + unsigned int cfg_table_len; + enum efi_type et; + int ret; + + et = efi_get_type(boot_params); + if (et == EFI_TYPE_NONE) + return false; + + ret = efi_get_conf_table(boot_params, &cfg_table_pa, &cfg_table_len); + if (ret) { + warn("EFI config table not found."); + return false; + } + + table = (void *)efi_find_vendor_table(boot_params, cfg_table_pa, + cfg_table_len, guid); + if (!table) + return false; + + if (table->version != 1) + error("Unknown version of unaccepted memory table\n"); + + /* + * In many cases unaccepted_table is already set by EFI stub, but it + * has to be initialized again to cover cases when the table is not + * allocated by EFI stub or EFI stub copied the kernel image with + * efi_relocate_kernel() before the variable is set. + * + * It must be initialized before the first usage of accept_memory(). + */ + unaccepted_table = table; + + return true; +} diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index 014ff222bf4b..94b7abcf624b 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -455,6 +455,12 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, #endif debug_putstr("\nDecompressing Linux... "); + + if (init_unaccepted_memory()) { + debug_putstr("Accepting memory... "); + accept_memory(__pa(output), __pa(output) + needed_size); + } + __decompress(input_data, input_len, NULL, NULL, output, output_len, NULL, error); entry_offset = parse_elf(output); diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index 2f155a0e3041..964fe903a1cd 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -247,4 +247,14 @@ static inline unsigned long efi_find_vendor_table(struct boot_params *bp, } #endif /* CONFIG_EFI */ +#ifdef CONFIG_UNACCEPTED_MEMORY +bool init_unaccepted_memory(void); +#else +static inline bool init_unaccepted_memory(void) { return false; } +#endif + +/* Defined in EFI stub */ +extern struct efi_unaccepted_memory *unaccepted_table; +void accept_memory(phys_addr_t start, phys_addr_t end); + #endif /* BOOT_COMPRESSED_MISC_H */ diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c index 014b89c89088..09dc8c187b3c 100644 --- a/arch/x86/boot/compressed/sev.c +++ b/arch/x86/boot/compressed/sev.c @@ -115,7 +115,7 @@ static enum es_result vc_read_mem(struct es_em_ctxt *ctxt, /* Include code for early handlers */ #include "../../kernel/sev-shared.c" -static inline bool sev_snp_enabled(void) +bool sev_snp_enabled(void) { return sev_status & MSR_AMD64_SEV_SNP_ENABLED; } @@ -181,6 +181,58 @@ static bool early_setup_ghcb(void) return true; } +static phys_addr_t __snp_accept_memory(struct snp_psc_desc *desc, + phys_addr_t pa, phys_addr_t pa_end) +{ + struct psc_hdr *hdr; + struct psc_entry *e; + unsigned int i; + + hdr = &desc->hdr; + memset(hdr, 0, sizeof(*hdr)); + + e = desc->entries; + + i = 0; + while (pa < pa_end && i < VMGEXIT_PSC_MAX_ENTRY) { + hdr->end_entry = i; + + e->gfn = pa >> PAGE_SHIFT; + e->operation = SNP_PAGE_STATE_PRIVATE; + if (IS_ALIGNED(pa, PMD_SIZE) && (pa_end - pa) >= PMD_SIZE) { + e->pagesize = RMP_PG_SIZE_2M; + pa += PMD_SIZE; + } else { + e->pagesize = RMP_PG_SIZE_4K; + pa += PAGE_SIZE; + } + + e++; + i++; + } + + if (vmgexit_psc(boot_ghcb, desc)) + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC); + + pvalidate_pages(desc); + + return pa; +} + +void snp_accept_memory(phys_addr_t start, phys_addr_t end) +{ + struct snp_psc_desc desc = {}; + unsigned int i; + phys_addr_t pa; + + if (!boot_ghcb && !early_setup_ghcb()) + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC); + + pa = start; + while (pa < end) + pa = __snp_accept_memory(&desc, pa, end); +} + void sev_es_shutdown_ghcb(void) { if (!boot_ghcb) diff --git a/arch/x86/boot/compressed/sev.h b/arch/x86/boot/compressed/sev.h new file mode 100644 index 000000000000..fc725a981b09 --- /dev/null +++ b/arch/x86/boot/compressed/sev.h @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * AMD SEV header for early boot related functions. + * + * Author: Tom Lendacky <thomas.lendacky@amd.com> + */ + +#ifndef BOOT_COMPRESSED_SEV_H +#define BOOT_COMPRESSED_SEV_H + +#ifdef CONFIG_AMD_MEM_ENCRYPT + +bool sev_snp_enabled(void); +void snp_accept_memory(phys_addr_t start, phys_addr_t end); + +#else + +static inline bool sev_snp_enabled(void) { return false; } +static inline void snp_accept_memory(phys_addr_t start, phys_addr_t end) { } + +#endif + +#endif diff --git a/arch/x86/boot/compressed/tdx-shared.c b/arch/x86/boot/compressed/tdx-shared.c new file mode 100644 index 000000000000..5ac43762fe13 --- /dev/null +++ b/arch/x86/boot/compressed/tdx-shared.c @@ -0,0 +1,2 @@ +#include "error.h" +#include "../../coco/tdx/tdx-shared.c" diff --git a/arch/x86/coco/tdx/Makefile b/arch/x86/coco/tdx/Makefile index 46c55998557d..2c7dcbf1458b 100644 --- a/arch/x86/coco/tdx/Makefile +++ b/arch/x86/coco/tdx/Makefile @@ -1,3 +1,3 @@ # SPDX-License-Identifier: GPL-2.0 -obj-y += tdx.o tdcall.o +obj-y += tdx.o tdx-shared.o tdcall.o diff --git a/arch/x86/coco/tdx/tdx-shared.c b/arch/x86/coco/tdx/tdx-shared.c new file mode 100644 index 000000000000..ef20ddc37b58 --- /dev/null +++ b/arch/x86/coco/tdx/tdx-shared.c @@ -0,0 +1,71 @@ +#include <asm/tdx.h> +#include <asm/pgtable.h> + +static unsigned long try_accept_one(phys_addr_t start, unsigned long len, + enum pg_level pg_level) +{ + unsigned long accept_size = page_level_size(pg_level); + u64 tdcall_rcx; + u8 page_size; + + if (!IS_ALIGNED(start, accept_size)) + return 0; + + if (len < accept_size) + return 0; + + /* + * Pass the page physical address to the TDX module to accept the + * pending, private page. + * + * Bits 2:0 of RCX encode page size: 0 - 4K, 1 - 2M, 2 - 1G. + */ + switch (pg_level) { + case PG_LEVEL_4K: + page_size = 0; + break; + case PG_LEVEL_2M: + page_size = 1; + break; + case PG_LEVEL_1G: + page_size = 2; + break; + default: + return 0; + } + + tdcall_rcx = start | page_size; + if (__tdx_module_call(TDX_ACCEPT_PAGE, tdcall_rcx, 0, 0, 0, NULL)) + return 0; + + return accept_size; +} + +bool tdx_accept_memory(phys_addr_t start, phys_addr_t end) +{ + /* + * For shared->private conversion, accept the page using + * TDX_ACCEPT_PAGE TDX module call. + */ + while (start < end) { + unsigned long len = end - start; + unsigned long accept_size; + + /* + * Try larger accepts first. It gives chance to VMM to keep + * 1G/2M Secure EPT entries where possible and speeds up + * process by cutting number of hypercalls (if successful). + */ + + accept_size = try_accept_one(start, len, PG_LEVEL_1G); + if (!accept_size) + accept_size = try_accept_one(start, len, PG_LEVEL_2M); + if (!accept_size) + accept_size = try_accept_one(start, len, PG_LEVEL_4K); + if (!accept_size) + return false; + start += accept_size; + } + + return true; +} diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c index 27ce10c9ff61..fe67c027a27b 100644 --- a/arch/x86/coco/tdx/tdx.c +++ b/arch/x86/coco/tdx/tdx.c @@ -14,20 +14,6 @@ #include <asm/insn-eval.h> #include <asm/pgtable.h> -/* TDX module Call Leaf IDs */ -#define TDX_GET_INFO 1 -#define TDX_GET_VEINFO 3 -#define TDX_GET_REPORT 4 -#define TDX_ACCEPT_PAGE 6 -#define TDX_WR 8 - -/* TDCS fields. To be used by TDG.VM.WR and TDG.VM.RD module calls */ -#define TDCS_NOTIFY_ENABLES 0x9100000000000010 - -/* TDX hypercall Leaf IDs */ -#define TDVMCALL_MAP_GPA 0x10001 -#define TDVMCALL_REPORT_FATAL_ERROR 0x10003 - /* MMIO direction */ #define EPT_READ 0 #define EPT_WRITE 1 @@ -51,24 +37,6 @@ #define TDREPORT_SUBTYPE_0 0 -/* - * Wrapper for standard use of __tdx_hypercall with no output aside from - * return code. - */ -static inline u64 _tdx_hypercall(u64 fn, u64 r12, u64 r13, u64 r14, u64 r15) -{ - struct tdx_hypercall_args args = { - .r10 = TDX_HYPERCALL_STANDARD, - .r11 = fn, - .r12 = r12, - .r13 = r13, - .r14 = r14, - .r15 = r15, - }; - - return __tdx_hypercall(&args); -} - /* Called from __tdx_hypercall() for unrecoverable failure */ noinstr void __tdx_hypercall_failed(void) { @@ -745,47 +713,6 @@ static bool tdx_cache_flush_required(void) return true; } -static bool try_accept_one(phys_addr_t *start, unsigned long len, - enum pg_level pg_level) -{ - unsigned long accept_size = page_level_size(pg_level); - u64 tdcall_rcx; - u8 page_size; - - if (!IS_ALIGNED(*start, accept_size)) - return false; - - if (len < accept_size) - return false; - - /* - * Pass the page physical address to the TDX module to accept the - * pending, private page. - * - * Bits 2:0 of RCX encode page size: 0 - 4K, 1 - 2M, 2 - 1G. - */ - switch (pg_level) { - case PG_LEVEL_4K: - page_size = 0; - break; - case PG_LEVEL_2M: - page_size = 1; - break; - case PG_LEVEL_1G: - page_size = 2; - break; - default: - return false; - } - - tdcall_rcx = *start | page_size; - if (__tdx_module_call(TDX_ACCEPT_PAGE, tdcall_rcx, 0, 0, 0, NULL)) - return false; - - *start += accept_size; - return true; -} - /* * Inform the VMM of the guest's intent for this physical page: shared with * the VMM or private to the guest. The VMM is expected to change its mapping @@ -810,32 +737,9 @@ static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc) if (_tdx_hypercall(TDVMCALL_MAP_GPA, start, end - start, 0, 0)) return false; - /* private->shared conversion requires only MapGPA call */ - if (!enc) - return true; - - /* - * For shared->private conversion, accept the page using - * TDX_ACCEPT_PAGE TDX module call. - */ - while (start < end) { - unsigned long len = end - start; - - /* - * Try larger accepts first. It gives chance to VMM to keep - * 1G/2M SEPT entries where possible and speeds up process by - * cutting number of hypercalls (if successful). - */ - - if (try_accept_one(&start, len, PG_LEVEL_1G)) - continue; - - if (try_accept_one(&start, len, PG_LEVEL_2M)) - continue; - - if (!try_accept_one(&start, len, PG_LEVEL_4K)) - return false; - } + /* shared->private conversion requires memory to be accepted before use */ + if (enc) + return tdx_accept_memory(start, end); return true; } diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index 419280d263d2..8b4be7cecdb8 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -31,6 +31,8 @@ extern unsigned long efi_mixed_mode_stack_pa; #define ARCH_EFI_IRQ_FLAGS_MASK X86_EFLAGS_IF +#define EFI_UNACCEPTED_UNIT_SIZE PMD_SIZE + /* * The EFI services are called through variadic functions in many cases. These * functions are implemented in assembler and support only a fixed number of diff --git a/arch/x86/include/asm/sev-common.h b/arch/x86/include/asm/sev-common.h index 0759af9b1acf..b463fcbd4b90 100644 --- a/arch/x86/include/asm/sev-common.h +++ b/arch/x86/include/asm/sev-common.h @@ -106,8 +106,13 @@ enum psc_op { #define GHCB_HV_FT_SNP BIT_ULL(0) #define GHCB_HV_FT_SNP_AP_CREATION BIT_ULL(1) -/* SNP Page State Change NAE event */ -#define VMGEXIT_PSC_MAX_ENTRY 253 +/* + * SNP Page State Change NAE event + * The VMGEXIT_PSC_MAX_ENTRY determines the size of the PSC structure, which + * is a local stack variable in set_pages_state(). Do not increase this value + * without evaluating the impact to stack usage. + */ +#define VMGEXIT_PSC_MAX_ENTRY 64 struct psc_hdr { u16 cur_entry; diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h index 13dc2a9d23c1..86e1296e87f5 100644 --- a/arch/x86/include/asm/sev.h +++ b/arch/x86/include/asm/sev.h @@ -80,11 +80,15 @@ extern void vc_no_ghcb(void); extern void vc_boot_ghcb(void); extern bool handle_vc_boot_ghcb(struct pt_regs *regs); +/* PVALIDATE return codes */ +#define PVALIDATE_FAIL_SIZEMISMATCH 6 + /* Software defined (when rFlags.CF = 1) */ #define PVALIDATE_FAIL_NOUPDATE 255 /* RMP page size */ #define RMP_PG_SIZE_4K 0 +#define RMP_PG_SIZE_2M 1 #define RMPADJUST_VMSA_PAGE_BIT BIT(16) @@ -192,16 +196,17 @@ struct snp_guest_request_ioctl; void setup_ghcb(void); void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr, - unsigned int npages); + unsigned long npages); void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr, - unsigned int npages); + unsigned long npages); void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op); -void snp_set_memory_shared(unsigned long vaddr, unsigned int npages); -void snp_set_memory_private(unsigned long vaddr, unsigned int npages); +void snp_set_memory_shared(unsigned long vaddr, unsigned long npages); +void snp_set_memory_private(unsigned long vaddr, unsigned long npages); void snp_set_wakeup_secondary_cpu(void); bool snp_init(struct boot_params *bp); void __init __noreturn snp_abort(void); int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio); +void snp_accept_memory(phys_addr_t start, phys_addr_t end); #else static inline void sev_es_ist_enter(struct pt_regs *regs) { } static inline void sev_es_ist_exit(void) { } @@ -212,12 +217,12 @@ static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate) static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs) { return 0; } static inline void setup_ghcb(void) { } static inline void __init -early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr, unsigned int npages) { } +early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr, unsigned long npages) { } static inline void __init -early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr, unsigned int npages) { } +early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr, unsigned long npages) { } static inline void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op) { } -static inline void snp_set_memory_shared(unsigned long vaddr, unsigned int npages) { } -static inline void snp_set_memory_private(unsigned long vaddr, unsigned int npages) { } +static inline void snp_set_memory_shared(unsigned long vaddr, unsigned long npages) { } +static inline void snp_set_memory_private(unsigned long vaddr, unsigned long npages) { } static inline void snp_set_wakeup_secondary_cpu(void) { } static inline bool snp_init(struct boot_params *bp) { return false; } static inline void snp_abort(void) { } @@ -225,6 +230,8 @@ static inline int snp_issue_guest_request(u64 exit_code, struct snp_req_data *in { return -ENOTTY; } + +static inline void snp_accept_memory(phys_addr_t start, phys_addr_t end) { } #endif #endif diff --git a/arch/x86/include/asm/shared/tdx.h b/arch/x86/include/asm/shared/tdx.h index 2631e01f6e0f..19228beb4894 100644 --- a/arch/x86/include/asm/shared/tdx.h +++ b/arch/x86/include/asm/shared/tdx.h @@ -10,6 +10,20 @@ #define TDX_CPUID_LEAF_ID 0x21 #define TDX_IDENT "IntelTDX " +/* TDX module Call Leaf IDs */ +#define TDX_GET_INFO 1 +#define TDX_GET_VEINFO 3 +#define TDX_GET_REPORT 4 +#define TDX_ACCEPT_PAGE 6 +#define TDX_WR 8 + +/* TDCS fields. To be used by TDG.VM.WR and TDG.VM.RD module calls */ +#define TDCS_NOTIFY_ENABLES 0x9100000000000010 + +/* TDX hypercall Leaf IDs */ +#define TDVMCALL_MAP_GPA 0x10001 +#define TDVMCALL_REPORT_FATAL_ERROR 0x10003 + #ifndef __ASSEMBLY__ /* @@ -37,8 +51,47 @@ struct tdx_hypercall_args { u64 __tdx_hypercall(struct tdx_hypercall_args *args); u64 __tdx_hypercall_ret(struct tdx_hypercall_args *args); +/* + * Wrapper for standard use of __tdx_hypercall with no output aside from + * return code. + */ +static inline u64 _tdx_hypercall(u64 fn, u64 r12, u64 r13, u64 r14, u64 r15) +{ + struct tdx_hypercall_args args = { + .r10 = TDX_HYPERCALL_STANDARD, + .r11 = fn, + .r12 = r12, + .r13 = r13, + .r14 = r14, + .r15 = r15, + }; + + return __tdx_hypercall(&args); +} + + /* Called from __tdx_hypercall() for unrecoverable failure */ void __tdx_hypercall_failed(void); +/* + * Used in __tdx_module_call() to gather the output registers' values of the + * TDCALL instruction when requesting services from the TDX module. This is a + * software only structure and not part of the TDX module/VMM ABI + */ +struct tdx_module_output { + u64 rcx; + u64 rdx; + u64 r8; + u64 r9; + u64 r10; + u64 r11; +}; + +/* Used to communicate with the TDX module */ +u64 __tdx_module_call(u64 fn, u64 rcx, u64 rdx, u64 r8, u64 r9, + struct tdx_module_output *out); + +bool tdx_accept_memory(phys_addr_t start, phys_addr_t end); + #endif /* !__ASSEMBLY__ */ #endif /* _ASM_X86_SHARED_TDX_H */ diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h index 28d889c9aa16..603e6d1e9d4a 100644 --- a/arch/x86/include/asm/tdx.h +++ b/arch/x86/include/asm/tdx.h @@ -5,6 +5,8 @@ #include <linux/init.h> #include <linux/bits.h> + +#include <asm/errno.h> #include <asm/ptrace.h> #include <asm/shared/tdx.h> @@ -21,21 +23,6 @@ #ifndef __ASSEMBLY__ /* - * Used to gather the output registers values of the TDCALL and SEAMCALL - * instructions when requesting services from the TDX module. - * - * This is a software only structure and not part of the TDX module/VMM ABI. - */ -struct tdx_module_output { - u64 rcx; - u64 rdx; - u64 r8; - u64 r9; - u64 r10; - u64 r11; -}; - -/* * Used by the #VE exception handler to gather the #VE exception * info from the TDX module. This is a software only structure * and not part of the TDX module/VMM ABI. @@ -55,10 +42,6 @@ struct ve_info { void __init tdx_early_init(void); -/* Used to communicate with the TDX module */ -u64 __tdx_module_call(u64 fn, u64 rcx, u64 rdx, u64 r8, u64 r9, - struct tdx_module_output *out); - void tdx_get_ve_info(struct ve_info *ve); bool tdx_handle_virt_exception(struct pt_regs *regs, struct ve_info *ve); diff --git a/arch/x86/include/asm/unaccepted_memory.h b/arch/x86/include/asm/unaccepted_memory.h new file mode 100644 index 000000000000..f5937e9866ac --- /dev/null +++ b/arch/x86/include/asm/unaccepted_memory.h @@ -0,0 +1,27 @@ +#ifndef _ASM_X86_UNACCEPTED_MEMORY_H +#define _ASM_X86_UNACCEPTED_MEMORY_H + +#include <linux/efi.h> +#include <asm/tdx.h> +#include <asm/sev.h> + +static inline void arch_accept_memory(phys_addr_t start, phys_addr_t end) +{ + /* Platform-specific memory-acceptance call goes here */ + if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST)) { + if (!tdx_accept_memory(start, end)) + panic("TDX: Failed to accept memory\n"); + } else if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) { + snp_accept_memory(start, end); + } else { + panic("Cannot accept memory: unknown platform\n"); + } +} + +static inline struct efi_unaccepted_memory *efi_get_unaccepted_table(void) +{ + if (efi.unaccepted == EFI_INVALID_TABLE_ADDR) + return NULL; + return __va(efi.unaccepted); +} +#endif diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c index 3a5b0c9c4fcc..2eabccde94fb 100644 --- a/arch/x86/kernel/sev-shared.c +++ b/arch/x86/kernel/sev-shared.c @@ -12,6 +12,9 @@ #ifndef __BOOT_COMPRESSED #define error(v) pr_err(v) #define has_cpuflag(f) boot_cpu_has(f) +#else +#undef WARN +#define WARN(condition, format...) (!!(condition)) #endif /* I/O parameters for CPUID-related helpers */ @@ -991,3 +994,103 @@ static void __init setup_cpuid_table(const struct cc_blob_sev_info *cc_info) cpuid_ext_range_max = fn->eax; } } + +static void pvalidate_pages(struct snp_psc_desc *desc) +{ + struct psc_entry *e; + unsigned long vaddr; + unsigned int size; + unsigned int i; + bool validate; + int rc; + + for (i = 0; i <= desc->hdr.end_entry; i++) { + e = &desc->entries[i]; + + vaddr = (unsigned long)pfn_to_kaddr(e->gfn); + size = e->pagesize ? RMP_PG_SIZE_2M : RMP_PG_SIZE_4K; + validate = e->operation == SNP_PAGE_STATE_PRIVATE; + + rc = pvalidate(vaddr, size, validate); + if (rc == PVALIDATE_FAIL_SIZEMISMATCH && size == RMP_PG_SIZE_2M) { + unsigned long vaddr_end = vaddr + PMD_SIZE; + + for (; vaddr < vaddr_end; vaddr += PAGE_SIZE) { + rc = pvalidate(vaddr, RMP_PG_SIZE_4K, validate); + if (rc) + break; + } + } + + if (rc) { + WARN(1, "Failed to validate address 0x%lx ret %d", vaddr, rc); + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PVALIDATE); + } + } +} + +static int vmgexit_psc(struct ghcb *ghcb, struct snp_psc_desc *desc) +{ + int cur_entry, end_entry, ret = 0; + struct snp_psc_desc *data; + struct es_em_ctxt ctxt; + + vc_ghcb_invalidate(ghcb); + + /* Copy the input desc into GHCB shared buffer */ + data = (struct snp_psc_desc *)ghcb->shared_buffer; + memcpy(ghcb->shared_buffer, desc, min_t(int, GHCB_SHARED_BUF_SIZE, sizeof(*desc))); + + /* + * As per the GHCB specification, the hypervisor can resume the guest + * before processing all the entries. Check whether all the entries + * are processed. If not, then keep retrying. Note, the hypervisor + * will update the data memory directly to indicate the status, so + * reference the data->hdr everywhere. + * + * The strategy here is to wait for the hypervisor to change the page + * state in the RMP table before guest accesses the memory pages. If the + * page state change was not successful, then later memory access will + * result in a crash. + */ + cur_entry = data->hdr.cur_entry; + end_entry = data->hdr.end_entry; + + while (data->hdr.cur_entry <= data->hdr.end_entry) { + ghcb_set_sw_scratch(ghcb, (u64)__pa(data)); + + /* This will advance the shared buffer data points to. */ + ret = sev_es_ghcb_hv_call(ghcb, &ctxt, SVM_VMGEXIT_PSC, 0, 0); + + /* + * Page State Change VMGEXIT can pass error code through + * exit_info_2. + */ + if (WARN(ret || ghcb->save.sw_exit_info_2, + "SNP: PSC failed ret=%d exit_info_2=%llx\n", + ret, ghcb->save.sw_exit_info_2)) { + ret = 1; + goto out; + } + + /* Verify that reserved bit is not set */ + if (WARN(data->hdr.reserved, "Reserved bit is set in the PSC header\n")) { + ret = 1; + goto out; + } + + /* + * Sanity check that entry processing is not going backwards. + * This will happen only if hypervisor is tricking us. + */ + if (WARN(data->hdr.end_entry > end_entry || cur_entry > data->hdr.cur_entry, +"SNP: PSC processing going backward, end_entry %d (got %d) cur_entry %d (got %d)\n", + end_entry, data->hdr.end_entry, cur_entry, data->hdr.cur_entry)) { + ret = 1; + goto out; + } + } + +out: + return ret; +} diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index d095a5d3c14a..a0af3908ed49 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -119,7 +119,19 @@ static DEFINE_PER_CPU(struct sev_es_save_area *, sev_vmsa); struct sev_config { __u64 debug : 1, - __reserved : 63; + + /* + * A flag used by __set_pages_state() that indicates when the + * per-CPU GHCB has been created and registered and thus can be + * used by the BSP instead of the early boot GHCB. + * + * For APs, the per-CPU GHCB is created before they are started + * and registered upon startup, so this flag can be used globally + * for the BSP and APs. + */ + ghcbs_initialized : 1, + + __reserved : 62; }; static struct sev_config sev_cfg __read_mostly; @@ -645,32 +657,26 @@ static u64 __init get_jump_table_addr(void) return ret; } -static void pvalidate_pages(unsigned long vaddr, unsigned int npages, bool validate) -{ - unsigned long vaddr_end; - int rc; - - vaddr = vaddr & PAGE_MASK; - vaddr_end = vaddr + (npages << PAGE_SHIFT); - - while (vaddr < vaddr_end) { - rc = pvalidate(vaddr, RMP_PG_SIZE_4K, validate); - if (WARN(rc, "Failed to validate address 0x%lx ret %d", vaddr, rc)) - sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PVALIDATE); - - vaddr = vaddr + PAGE_SIZE; - } -} - -static void __init early_set_pages_state(unsigned long paddr, unsigned int npages, enum psc_op op) +static void early_set_pages_state(unsigned long vaddr, unsigned long paddr, + unsigned long npages, enum psc_op op) { unsigned long paddr_end; u64 val; + int ret; + + vaddr = vaddr & PAGE_MASK; paddr = paddr & PAGE_MASK; paddr_end = paddr + (npages << PAGE_SHIFT); while (paddr < paddr_end) { + if (op == SNP_PAGE_STATE_SHARED) { + /* Page validation must be rescinded before changing to shared */ + ret = pvalidate(vaddr, RMP_PG_SIZE_4K, false); + if (WARN(ret, "Failed to validate address 0x%lx ret %d", paddr, ret)) + goto e_term; + } + /* * Use the MSR protocol because this function can be called before * the GHCB is established. @@ -691,7 +697,15 @@ static void __init early_set_pages_state(unsigned long paddr, unsigned int npage paddr, GHCB_MSR_PSC_RESP_VAL(val))) goto e_term; - paddr = paddr + PAGE_SIZE; + if (op == SNP_PAGE_STATE_PRIVATE) { + /* Page validation must be performed after changing to private */ + ret = pvalidate(vaddr, RMP_PG_SIZE_4K, true); + if (WARN(ret, "Failed to validate address 0x%lx ret %d", paddr, ret)) + goto e_term; + } + + vaddr += PAGE_SIZE; + paddr += PAGE_SIZE; } return; @@ -701,7 +715,7 @@ e_term: } void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr, - unsigned int npages) + unsigned long npages) { /* * This can be invoked in early boot while running identity mapped, so @@ -716,14 +730,11 @@ void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long padd * Ask the hypervisor to mark the memory pages as private in the RMP * table. */ - early_set_pages_state(paddr, npages, SNP_PAGE_STATE_PRIVATE); - - /* Validate the memory pages after they've been added in the RMP table. */ - pvalidate_pages(vaddr, npages, true); + early_set_pages_state(vaddr, paddr, npages, SNP_PAGE_STATE_PRIVATE); } void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr, - unsigned int npages) + unsigned long npages) { /* * This can be invoked in early boot while running identity mapped, so @@ -734,11 +745,8 @@ void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr if (!(sev_status & MSR_AMD64_SEV_SNP_ENABLED)) return; - /* Invalidate the memory pages before they are marked shared in the RMP table. */ - pvalidate_pages(vaddr, npages, false); - /* Ask hypervisor to mark the memory pages shared in the RMP table. */ - early_set_pages_state(paddr, npages, SNP_PAGE_STATE_SHARED); + early_set_pages_state(vaddr, paddr, npages, SNP_PAGE_STATE_SHARED); } void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op) @@ -756,96 +764,16 @@ void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op WARN(1, "invalid memory op %d\n", op); } -static int vmgexit_psc(struct snp_psc_desc *desc) +static unsigned long __set_pages_state(struct snp_psc_desc *data, unsigned long vaddr, + unsigned long vaddr_end, int op) { - int cur_entry, end_entry, ret = 0; - struct snp_psc_desc *data; struct ghcb_state state; - struct es_em_ctxt ctxt; - unsigned long flags; - struct ghcb *ghcb; - - /* - * __sev_get_ghcb() needs to run with IRQs disabled because it is using - * a per-CPU GHCB. - */ - local_irq_save(flags); - - ghcb = __sev_get_ghcb(&state); - if (!ghcb) { - ret = 1; - goto out_unlock; - } - - /* Copy the input desc into GHCB shared buffer */ - data = (struct snp_psc_desc *)ghcb->shared_buffer; - memcpy(ghcb->shared_buffer, desc, min_t(int, GHCB_SHARED_BUF_SIZE, sizeof(*desc))); - - /* - * As per the GHCB specification, the hypervisor can resume the guest - * before processing all the entries. Check whether all the entries - * are processed. If not, then keep retrying. Note, the hypervisor - * will update the data memory directly to indicate the status, so - * reference the data->hdr everywhere. - * - * The strategy here is to wait for the hypervisor to change the page - * state in the RMP table before guest accesses the memory pages. If the - * page state change was not successful, then later memory access will - * result in a crash. - */ - cur_entry = data->hdr.cur_entry; - end_entry = data->hdr.end_entry; - - while (data->hdr.cur_entry <= data->hdr.end_entry) { - ghcb_set_sw_scratch(ghcb, (u64)__pa(data)); - - /* This will advance the shared buffer data points to. */ - ret = sev_es_ghcb_hv_call(ghcb, &ctxt, SVM_VMGEXIT_PSC, 0, 0); - - /* - * Page State Change VMGEXIT can pass error code through - * exit_info_2. - */ - if (WARN(ret || ghcb->save.sw_exit_info_2, - "SNP: PSC failed ret=%d exit_info_2=%llx\n", - ret, ghcb->save.sw_exit_info_2)) { - ret = 1; - goto out; - } - - /* Verify that reserved bit is not set */ - if (WARN(data->hdr.reserved, "Reserved bit is set in the PSC header\n")) { - ret = 1; - goto out; - } - - /* - * Sanity check that entry processing is not going backwards. - * This will happen only if hypervisor is tricking us. - */ - if (WARN(data->hdr.end_entry > end_entry || cur_entry > data->hdr.cur_entry, -"SNP: PSC processing going backward, end_entry %d (got %d) cur_entry %d (got %d)\n", - end_entry, data->hdr.end_entry, cur_entry, data->hdr.cur_entry)) { - ret = 1; - goto out; - } - } - -out: - __sev_put_ghcb(&state); - -out_unlock: - local_irq_restore(flags); - - return ret; -} - -static void __set_pages_state(struct snp_psc_desc *data, unsigned long vaddr, - unsigned long vaddr_end, int op) -{ + bool use_large_entry; struct psc_hdr *hdr; struct psc_entry *e; + unsigned long flags; unsigned long pfn; + struct ghcb *ghcb; int i; hdr = &data->hdr; @@ -854,74 +782,104 @@ static void __set_pages_state(struct snp_psc_desc *data, unsigned long vaddr, memset(data, 0, sizeof(*data)); i = 0; - while (vaddr < vaddr_end) { - if (is_vmalloc_addr((void *)vaddr)) + while (vaddr < vaddr_end && i < ARRAY_SIZE(data->entries)) { + hdr->end_entry = i; + + if (is_vmalloc_addr((void *)vaddr)) { pfn = vmalloc_to_pfn((void *)vaddr); - else + use_large_entry = false; + } else { pfn = __pa(vaddr) >> PAGE_SHIFT; + use_large_entry = true; + } e->gfn = pfn; e->operation = op; - hdr->end_entry = i; - /* - * Current SNP implementation doesn't keep track of the RMP page - * size so use 4K for simplicity. - */ - e->pagesize = RMP_PG_SIZE_4K; + if (use_large_entry && IS_ALIGNED(vaddr, PMD_SIZE) && + (vaddr_end - vaddr) >= PMD_SIZE) { + e->pagesize = RMP_PG_SIZE_2M; + vaddr += PMD_SIZE; + } else { + e->pagesize = RMP_PG_SIZE_4K; + vaddr += PAGE_SIZE; + } - vaddr = vaddr + PAGE_SIZE; e++; i++; } - if (vmgexit_psc(data)) + /* Page validation must be rescinded before changing to shared */ + if (op == SNP_PAGE_STATE_SHARED) + pvalidate_pages(data); + + local_irq_save(flags); + + if (sev_cfg.ghcbs_initialized) + ghcb = __sev_get_ghcb(&state); + else + ghcb = boot_ghcb; + + /* Invoke the hypervisor to perform the page state changes */ + if (!ghcb || vmgexit_psc(ghcb, data)) sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC); + + if (sev_cfg.ghcbs_initialized) + __sev_put_ghcb(&state); + + local_irq_restore(flags); + + /* Page validation must be performed after changing to private */ + if (op == SNP_PAGE_STATE_PRIVATE) + pvalidate_pages(data); + + return vaddr; } -static void set_pages_state(unsigned long vaddr, unsigned int npages, int op) +static void set_pages_state(unsigned long vaddr, unsigned long npages, int op) { - unsigned long vaddr_end, next_vaddr; - struct snp_psc_desc *desc; + struct snp_psc_desc desc; + unsigned long vaddr_end; - desc = kmalloc(sizeof(*desc), GFP_KERNEL_ACCOUNT); - if (!desc) - panic("SNP: failed to allocate memory for PSC descriptor\n"); + /* Use the MSR protocol when a GHCB is not available. */ + if (!boot_ghcb) + return early_set_pages_state(vaddr, __pa(vaddr), npages, op); vaddr = vaddr & PAGE_MASK; vaddr_end = vaddr + (npages << PAGE_SHIFT); - while (vaddr < vaddr_end) { - /* Calculate the last vaddr that fits in one struct snp_psc_desc. */ - next_vaddr = min_t(unsigned long, vaddr_end, - (VMGEXIT_PSC_MAX_ENTRY * PAGE_SIZE) + vaddr); - - __set_pages_state(desc, vaddr, next_vaddr, op); - - vaddr = next_vaddr; - } - - kfree(desc); + while (vaddr < vaddr_end) + vaddr = __set_pages_state(&desc, vaddr, vaddr_end, op); } -void snp_set_memory_shared(unsigned long vaddr, unsigned int npages) +void snp_set_memory_shared(unsigned long vaddr, unsigned long npages) { if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) return; - pvalidate_pages(vaddr, npages, false); - set_pages_state(vaddr, npages, SNP_PAGE_STATE_SHARED); } -void snp_set_memory_private(unsigned long vaddr, unsigned int npages) +void snp_set_memory_private(unsigned long vaddr, unsigned long npages) { if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) return; set_pages_state(vaddr, npages, SNP_PAGE_STATE_PRIVATE); +} + +void snp_accept_memory(phys_addr_t start, phys_addr_t end) +{ + unsigned long vaddr; + unsigned int npages; - pvalidate_pages(vaddr, npages, true); + if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) + return; + + vaddr = (unsigned long)__va(start); + npages = (end - start) >> PAGE_SHIFT; + + set_pages_state(vaddr, npages, SNP_PAGE_STATE_PRIVATE); } static int snp_set_vmsa(void *va, bool vmsa) @@ -1267,6 +1225,8 @@ void setup_ghcb(void) if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) snp_register_per_cpu_ghcb(); + sev_cfg.ghcbs_initialized = true; + return; } diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index f3f2d87cce1b..e9f99c56f3ce 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -96,6 +96,9 @@ static const unsigned long * const efi_tables[] = { #ifdef CONFIG_EFI_COCO_SECRET &efi.coco_secret, #endif +#ifdef CONFIG_UNACCEPTED_MEMORY + &efi.unaccepted, +#endif }; u64 efi_setup; /* efi setup_data physical address */ diff --git a/drivers/base/node.c b/drivers/base/node.c index b46db17124f3..655975946ef6 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -449,6 +449,9 @@ static ssize_t node_read_meminfo(struct device *dev, "Node %d FileHugePages: %8lu kB\n" "Node %d FilePmdMapped: %8lu kB\n" #endif +#ifdef CONFIG_UNACCEPTED_MEMORY + "Node %d Unaccepted: %8lu kB\n" +#endif , nid, K(node_page_state(pgdat, NR_FILE_DIRTY)), nid, K(node_page_state(pgdat, NR_WRITEBACK)), @@ -478,6 +481,10 @@ static ssize_t node_read_meminfo(struct device *dev, nid, K(node_page_state(pgdat, NR_FILE_THPS)), nid, K(node_page_state(pgdat, NR_FILE_PMDMAPPED)) #endif +#ifdef CONFIG_UNACCEPTED_MEMORY + , + nid, K(sum_zone_node_page_state(nid, NR_UNACCEPTED)) +#endif ); len += hugetlb_report_node_meminfo(buf, len, nid); return len; diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index 043ca31c114e..231f1c70d1db 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -269,6 +269,20 @@ config EFI_COCO_SECRET virt/coco/efi_secret module to access the secrets, which in turn allows userspace programs to access the injected secrets. +config UNACCEPTED_MEMORY + bool + depends on EFI_STUB + help + Some Virtual Machine platforms, such as Intel TDX, require + some memory to be "accepted" by the guest before it can be used. + This mechanism helps prevent malicious hosts from making changes + to guest memory. + + UEFI specification v2.9 introduced EFI_UNACCEPTED_MEMORY memory type. + + This option adds support for unaccepted memory and makes such memory + usable by the kernel. + config EFI_EMBEDDED_FIRMWARE bool select CRYPTO_LIB_SHA256 diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile index b51f2a4c821e..e489fefd23da 100644 --- a/drivers/firmware/efi/Makefile +++ b/drivers/firmware/efi/Makefile @@ -41,3 +41,4 @@ obj-$(CONFIG_EFI_CAPSULE_LOADER) += capsule-loader.o obj-$(CONFIG_EFI_EARLYCON) += earlycon.o obj-$(CONFIG_UEFI_CPER_ARM) += cper-arm.o obj-$(CONFIG_UEFI_CPER_X86) += cper-x86.o +obj-$(CONFIG_UNACCEPTED_MEMORY) += unaccepted_memory.o diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 34b9e7876538..3a6ee7bb06f1 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -50,6 +50,9 @@ struct efi __read_mostly efi = { #ifdef CONFIG_EFI_COCO_SECRET .coco_secret = EFI_INVALID_TABLE_ADDR, #endif +#ifdef CONFIG_UNACCEPTED_MEMORY + .unaccepted = EFI_INVALID_TABLE_ADDR, +#endif }; EXPORT_SYMBOL(efi); @@ -584,6 +587,9 @@ static const efi_config_table_type_t common_tables[] __initconst = { #ifdef CONFIG_EFI_COCO_SECRET {LINUX_EFI_COCO_SECRET_AREA_GUID, &efi.coco_secret, "CocoSecret" }, #endif +#ifdef CONFIG_UNACCEPTED_MEMORY + {LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID, &efi.unaccepted, "Unaccepted" }, +#endif #ifdef CONFIG_EFI_GENERIC_STUB {LINUX_EFI_SCREEN_INFO_TABLE_GUID, &screen_info_table }, #endif @@ -738,6 +744,25 @@ int __init efi_config_parse_tables(const efi_config_table_t *config_tables, } } + if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) && + efi.unaccepted != EFI_INVALID_TABLE_ADDR) { + struct efi_unaccepted_memory *unaccepted; + + unaccepted = early_memremap(efi.unaccepted, sizeof(*unaccepted)); + if (unaccepted) { + unsigned long size; + + if (unaccepted->version == 1) { + size = sizeof(*unaccepted) + unaccepted->size; + memblock_reserve(efi.unaccepted, size); + } else { + efi.unaccepted = EFI_INVALID_TABLE_ADDR; + } + + early_memunmap(unaccepted, sizeof(*unaccepted)); + } + } + return 0; } @@ -822,6 +847,7 @@ static __initdata char memory_type_name[][13] = { "MMIO Port", "PAL Code", "Persistent", + "Unaccepted", }; char * __init efi_md_typeattr_format(char *buf, size_t size, diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index 3abb2b357482..16d64a34d1e1 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -96,6 +96,8 @@ CFLAGS_arm32-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET) zboot-obj-$(CONFIG_RISCV) := lib-clz_ctz.o lib-ashldi3.o lib-$(CONFIG_EFI_ZBOOT) += zboot.o $(zboot-obj-y) +lib-$(CONFIG_UNACCEPTED_MEMORY) += unaccepted_memory.o bitmap.o find.o + extra-y := $(lib-y) lib-y := $(patsubst %.o,%.stub.o,$(lib-y)) diff --git a/drivers/firmware/efi/libstub/bitmap.c b/drivers/firmware/efi/libstub/bitmap.c new file mode 100644 index 000000000000..5c9bba0d549b --- /dev/null +++ b/drivers/firmware/efi/libstub/bitmap.c @@ -0,0 +1,41 @@ +#include <linux/bitmap.h> + +void __bitmap_set(unsigned long *map, unsigned int start, int len) +{ + unsigned long *p = map + BIT_WORD(start); + const unsigned int size = start + len; + int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); + unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); + + while (len - bits_to_set >= 0) { + *p |= mask_to_set; + len -= bits_to_set; + bits_to_set = BITS_PER_LONG; + mask_to_set = ~0UL; + p++; + } + if (len) { + mask_to_set &= BITMAP_LAST_WORD_MASK(size); + *p |= mask_to_set; + } +} + +void __bitmap_clear(unsigned long *map, unsigned int start, int len) +{ + unsigned long *p = map + BIT_WORD(start); + const unsigned int size = start + len; + int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); + unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); + + while (len - bits_to_clear >= 0) { + *p &= ~mask_to_clear; + len -= bits_to_clear; + bits_to_clear = BITS_PER_LONG; + mask_to_clear = ~0UL; + p++; + } + if (len) { + mask_to_clear &= BITMAP_LAST_WORD_MASK(size); + *p &= ~mask_to_clear; + } +} diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h index 54a2822cae77..6aa38a1bf126 100644 --- a/drivers/firmware/efi/libstub/efistub.h +++ b/drivers/firmware/efi/libstub/efistub.h @@ -1136,4 +1136,10 @@ void efi_remap_image(unsigned long image_base, unsigned alloc_size, asmlinkage efi_status_t __efiapi efi_zboot_entry(efi_handle_t handle, efi_system_table_t *systab); +efi_status_t allocate_unaccepted_bitmap(__u32 nr_desc, + struct efi_boot_memmap *map); +void process_unaccepted_memory(u64 start, u64 end); +void accept_memory(phys_addr_t start, phys_addr_t end); +void arch_accept_memory(phys_addr_t start, phys_addr_t end); + #endif diff --git a/drivers/firmware/efi/libstub/find.c b/drivers/firmware/efi/libstub/find.c new file mode 100644 index 000000000000..4e7740d28987 --- /dev/null +++ b/drivers/firmware/efi/libstub/find.c @@ -0,0 +1,43 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <linux/bitmap.h> +#include <linux/math.h> +#include <linux/minmax.h> + +/* + * Common helper for find_next_bit() function family + * @FETCH: The expression that fetches and pre-processes each word of bitmap(s) + * @MUNGE: The expression that post-processes a word containing found bit (may be empty) + * @size: The bitmap size in bits + * @start: The bitnumber to start searching at + */ +#define FIND_NEXT_BIT(FETCH, MUNGE, size, start) \ +({ \ + unsigned long mask, idx, tmp, sz = (size), __start = (start); \ + \ + if (unlikely(__start >= sz)) \ + goto out; \ + \ + mask = MUNGE(BITMAP_FIRST_WORD_MASK(__start)); \ + idx = __start / BITS_PER_LONG; \ + \ + for (tmp = (FETCH) & mask; !tmp; tmp = (FETCH)) { \ + if ((idx + 1) * BITS_PER_LONG >= sz) \ + goto out; \ + idx++; \ + } \ + \ + sz = min(idx * BITS_PER_LONG + __ffs(MUNGE(tmp)), sz); \ +out: \ + sz; \ +}) + +unsigned long _find_next_bit(const unsigned long *addr, unsigned long nbits, unsigned long start) +{ + return FIND_NEXT_BIT(addr[idx], /* nop */, nbits, start); +} + +unsigned long _find_next_zero_bit(const unsigned long *addr, unsigned long nbits, + unsigned long start) +{ + return FIND_NEXT_BIT(~addr[idx], /* nop */, nbits, start); +} diff --git a/drivers/firmware/efi/libstub/unaccepted_memory.c b/drivers/firmware/efi/libstub/unaccepted_memory.c new file mode 100644 index 000000000000..ca61f4733ea5 --- /dev/null +++ b/drivers/firmware/efi/libstub/unaccepted_memory.c @@ -0,0 +1,222 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <linux/efi.h> +#include <asm/efi.h> +#include "efistub.h" + +struct efi_unaccepted_memory *unaccepted_table; + +efi_status_t allocate_unaccepted_bitmap(__u32 nr_desc, + struct efi_boot_memmap *map) +{ + efi_guid_t unaccepted_table_guid = LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID; + u64 unaccepted_start = ULLONG_MAX, unaccepted_end = 0, bitmap_size; + efi_status_t status; + int i; + + /* Check if the table is already installed */ + unaccepted_table = get_efi_config_table(unaccepted_table_guid); + if (unaccepted_table) { + if (unaccepted_table->version != 1) { + efi_err("Unknown version of unaccepted memory table\n"); + return EFI_UNSUPPORTED; + } + return EFI_SUCCESS; + } + + /* Check if there's any unaccepted memory and find the max address */ + for (i = 0; i < nr_desc; i++) { + efi_memory_desc_t *d; + unsigned long m = (unsigned long)map->map; + + d = efi_early_memdesc_ptr(m, map->desc_size, i); + if (d->type != EFI_UNACCEPTED_MEMORY) + continue; + + unaccepted_start = min(unaccepted_start, d->phys_addr); + unaccepted_end = max(unaccepted_end, + d->phys_addr + d->num_pages * PAGE_SIZE); + } + + if (unaccepted_start == ULLONG_MAX) + return EFI_SUCCESS; + + unaccepted_start = round_down(unaccepted_start, + EFI_UNACCEPTED_UNIT_SIZE); + unaccepted_end = round_up(unaccepted_end, EFI_UNACCEPTED_UNIT_SIZE); + + /* + * If unaccepted memory is present, allocate a bitmap to track what + * memory has to be accepted before access. + * + * One bit in the bitmap represents 2MiB in the address space: + * A 4k bitmap can track 64GiB of physical address space. + * + * In the worst case scenario -- a huge hole in the middle of the + * address space -- It needs 256MiB to handle 4PiB of the address + * space. + * + * The bitmap will be populated in setup_e820() according to the memory + * map after efi_exit_boot_services(). + */ + bitmap_size = DIV_ROUND_UP(unaccepted_end - unaccepted_start, + EFI_UNACCEPTED_UNIT_SIZE * BITS_PER_BYTE); + + status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, + sizeof(*unaccepted_table) + bitmap_size, + (void **)&unaccepted_table); + if (status != EFI_SUCCESS) { + efi_err("Failed to allocate unaccepted memory config table\n"); + return status; + } + + unaccepted_table->version = 1; + unaccepted_table->unit_size = EFI_UNACCEPTED_UNIT_SIZE; + unaccepted_table->phys_base = unaccepted_start; + unaccepted_table->size = bitmap_size; + memset(unaccepted_table->bitmap, 0, bitmap_size); + + status = efi_bs_call(install_configuration_table, + &unaccepted_table_guid, unaccepted_table); + if (status != EFI_SUCCESS) { + efi_bs_call(free_pool, unaccepted_table); + efi_err("Failed to install unaccepted memory config table!\n"); + } + + return status; +} + +/* + * The accepted memory bitmap only works at unit_size granularity. Take + * unaligned start/end addresses and either: + * 1. Accepts the memory immediately and in its entirety + * 2. Accepts unaligned parts, and marks *some* aligned part unaccepted + * + * The function will never reach the bitmap_set() with zero bits to set. + */ +void process_unaccepted_memory(u64 start, u64 end) +{ + u64 unit_size = unaccepted_table->unit_size; + u64 unit_mask = unaccepted_table->unit_size - 1; + u64 bitmap_size = unaccepted_table->size; + + /* + * Ensure that at least one bit will be set in the bitmap by + * immediately accepting all regions under 2*unit_size. This is + * imprecise and may immediately accept some areas that could + * have been represented in the bitmap. But, results in simpler + * code below + * + * Consider case like this (assuming unit_size == 2MB): + * + * | 4k | 2044k | 2048k | + * ^ 0x0 ^ 2MB ^ 4MB + * + * Only the first 4k has been accepted. The 0MB->2MB region can not be + * represented in the bitmap. The 2MB->4MB region can be represented in + * the bitmap. But, the 0MB->4MB region is <2*unit_size and will be + * immediately accepted in its entirety. + */ + if (end - start < 2 * unit_size) { + arch_accept_memory(start, end); + return; + } + + /* + * No matter how the start and end are aligned, at least one unaccepted + * unit_size area will remain to be marked in the bitmap. + */ + + /* Immediately accept a <unit_size piece at the start: */ + if (start & unit_mask) { + arch_accept_memory(start, round_up(start, unit_size)); + start = round_up(start, unit_size); + } + + /* Immediately accept a <unit_size piece at the end: */ + if (end & unit_mask) { + arch_accept_memory(round_down(end, unit_size), end); + end = round_down(end, unit_size); + } + + /* + * Accept part of the range that before phys_base and cannot be recorded + * into the bitmap. + */ + if (start < unaccepted_table->phys_base) { + arch_accept_memory(start, + min(unaccepted_table->phys_base, end)); + start = unaccepted_table->phys_base; + } + + /* Nothing to record */ + if (end < unaccepted_table->phys_base) + return; + + /* Translate to offsets from the beginning of the bitmap */ + start -= unaccepted_table->phys_base; + end -= unaccepted_table->phys_base; + + /* Accept memory that doesn't fit into bitmap */ + if (end > bitmap_size * unit_size * BITS_PER_BYTE) { + unsigned long phys_start, phys_end; + + phys_start = bitmap_size * unit_size * BITS_PER_BYTE + + unaccepted_table->phys_base; + phys_end = end + unaccepted_table->phys_base; + + arch_accept_memory(phys_start, phys_end); + end = bitmap_size * unit_size * BITS_PER_BYTE; + } + + /* + * 'start' and 'end' are now both unit_size-aligned. + * Record the range as being unaccepted: + */ + bitmap_set(unaccepted_table->bitmap, + start / unit_size, (end - start) / unit_size); +} + +void accept_memory(phys_addr_t start, phys_addr_t end) +{ + unsigned long range_start, range_end; + unsigned long bitmap_size; + u64 unit_size; + + if (!unaccepted_table) + return; + + unit_size = unaccepted_table->unit_size; + + /* + * Only care for the part of the range that is represented + * in the bitmap. + */ + if (start < unaccepted_table->phys_base) + start = unaccepted_table->phys_base; + if (end < unaccepted_table->phys_base) + return; + + /* Translate to offsets from the beginning of the bitmap */ + start -= unaccepted_table->phys_base; + end -= unaccepted_table->phys_base; + + /* Make sure not to overrun the bitmap */ + if (end > unaccepted_table->size * unit_size * BITS_PER_BYTE) + end = unaccepted_table->size * unit_size * BITS_PER_BYTE; + + range_start = start / unit_size; + bitmap_size = DIV_ROUND_UP(end, unit_size); + + for_each_set_bitrange_from(range_start, range_end, + unaccepted_table->bitmap, bitmap_size) { + unsigned long phys_start, phys_end; + + phys_start = range_start * unit_size + unaccepted_table->phys_base; + phys_end = range_end * unit_size + unaccepted_table->phys_base; + + arch_accept_memory(phys_start, phys_end); + bitmap_clear(unaccepted_table->bitmap, + range_start, range_end - range_start); + } +} diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c index a0bfd31358ba..220be75a5cdc 100644 --- a/drivers/firmware/efi/libstub/x86-stub.c +++ b/drivers/firmware/efi/libstub/x86-stub.c @@ -26,6 +26,17 @@ const efi_dxe_services_table_t *efi_dxe_table; u32 image_offset __section(".data"); static efi_loaded_image_t *image = NULL; +typedef union sev_memory_acceptance_protocol sev_memory_acceptance_protocol_t; +union sev_memory_acceptance_protocol { + struct { + efi_status_t (__efiapi * allow_unaccepted_memory)( + sev_memory_acceptance_protocol_t *); + }; + struct { + u32 allow_unaccepted_memory; + } mixed_mode; +}; + static efi_status_t preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom) { @@ -310,6 +321,29 @@ setup_memory_protection(unsigned long image_base, unsigned long image_size) #endif } +static void setup_unaccepted_memory(void) +{ + efi_guid_t mem_acceptance_proto = OVMF_SEV_MEMORY_ACCEPTANCE_PROTOCOL_GUID; + sev_memory_acceptance_protocol_t *proto; + efi_status_t status; + + if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY)) + return; + + /* + * Enable unaccepted memory before calling exit boot services in order + * for the UEFI to not accept all memory on EBS. + */ + status = efi_bs_call(locate_protocol, &mem_acceptance_proto, NULL, + (void **)&proto); + if (status != EFI_SUCCESS) + return; + + status = efi_call_proto(proto, allow_unaccepted_memory); + if (status != EFI_SUCCESS) + efi_err("Memory acceptance protocol failed\n"); +} + static const efi_char16_t apple[] = L"Apple"; static void setup_quirks(struct boot_params *boot_params, @@ -613,6 +647,16 @@ setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_s e820_type = E820_TYPE_PMEM; break; + case EFI_UNACCEPTED_MEMORY: + if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY)) { + efi_warn_once( +"The system has unaccepted memory, but kernel does not support it\nConsider enabling CONFIG_UNACCEPTED_MEMORY\n"); + continue; + } + e820_type = E820_TYPE_RAM; + process_unaccepted_memory(d->phys_addr, + d->phys_addr + PAGE_SIZE * d->num_pages); + break; default: continue; } @@ -681,28 +725,27 @@ static efi_status_t allocate_e820(struct boot_params *params, struct setup_data **e820ext, u32 *e820ext_size) { - unsigned long map_size, desc_size, map_key; + struct efi_boot_memmap *map; efi_status_t status; - __u32 nr_desc, desc_version; - - /* Only need the size of the mem map and size of each mem descriptor */ - map_size = 0; - status = efi_bs_call(get_memory_map, &map_size, NULL, &map_key, - &desc_size, &desc_version); - if (status != EFI_BUFFER_TOO_SMALL) - return (status != EFI_SUCCESS) ? status : EFI_UNSUPPORTED; + __u32 nr_desc; - nr_desc = map_size / desc_size + EFI_MMAP_NR_SLACK_SLOTS; + status = efi_get_memory_map(&map, false); + if (status != EFI_SUCCESS) + return status; - if (nr_desc > ARRAY_SIZE(params->e820_table)) { - u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table); + nr_desc = map->map_size / map->desc_size; + if (nr_desc > ARRAY_SIZE(params->e820_table) - EFI_MMAP_NR_SLACK_SLOTS) { + u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table) + + EFI_MMAP_NR_SLACK_SLOTS; status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size); - if (status != EFI_SUCCESS) - return status; } - return EFI_SUCCESS; + if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) && status == EFI_SUCCESS) + status = allocate_unaccepted_bitmap(nr_desc, map); + + efi_bs_call(free_pool, map); + return status; } struct exit_boot_struct { @@ -899,6 +942,8 @@ asmlinkage unsigned long efi_main(efi_handle_t handle, setup_quirks(boot_params, bzimage_addr, buffer_end - buffer_start); + setup_unaccepted_memory(); + status = exit_boot(boot_params, handle); if (status != EFI_SUCCESS) { efi_err("exit_boot() failed!\n"); diff --git a/drivers/firmware/efi/unaccepted_memory.c b/drivers/firmware/efi/unaccepted_memory.c new file mode 100644 index 000000000000..853f7dc3c21d --- /dev/null +++ b/drivers/firmware/efi/unaccepted_memory.c @@ -0,0 +1,147 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <linux/efi.h> +#include <linux/memblock.h> +#include <linux/spinlock.h> +#include <asm/unaccepted_memory.h> + +/* Protects unaccepted memory bitmap */ +static DEFINE_SPINLOCK(unaccepted_memory_lock); + +/* + * accept_memory() -- Consult bitmap and accept the memory if needed. + * + * Only memory that is explicitly marked as unaccepted in the bitmap requires + * an action. All the remaining memory is implicitly accepted and doesn't need + * acceptance. + * + * No need to accept: + * - anything if the system has no unaccepted table; + * - memory that is below phys_base; + * - memory that is above the memory that addressable by the bitmap; + */ +void accept_memory(phys_addr_t start, phys_addr_t end) +{ + struct efi_unaccepted_memory *unaccepted; + unsigned long range_start, range_end; + unsigned long flags; + u64 unit_size; + + unaccepted = efi_get_unaccepted_table(); + if (!unaccepted) + return; + + unit_size = unaccepted->unit_size; + + /* + * Only care for the part of the range that is represented + * in the bitmap. + */ + if (start < unaccepted->phys_base) + start = unaccepted->phys_base; + if (end < unaccepted->phys_base) + return; + + /* Translate to offsets from the beginning of the bitmap */ + start -= unaccepted->phys_base; + end -= unaccepted->phys_base; + + /* + * load_unaligned_zeropad() can lead to unwanted loads across page + * boundaries. The unwanted loads are typically harmless. But, they + * might be made to totally unrelated or even unmapped memory. + * load_unaligned_zeropad() relies on exception fixup (#PF, #GP and now + * #VE) to recover from these unwanted loads. + * + * But, this approach does not work for unaccepted memory. For TDX, a + * load from unaccepted memory will not lead to a recoverable exception + * within the guest. The guest will exit to the VMM where the only + * recourse is to terminate the guest. + * + * There are two parts to fix this issue and comprehensively avoid + * access to unaccepted memory. Together these ensure that an extra + * "guard" page is accepted in addition to the memory that needs to be + * used: + * + * 1. Implicitly extend the range_contains_unaccepted_memory(start, end) + * checks up to end+unit_size if 'end' is aligned on a unit_size + * boundary. + * + * 2. Implicitly extend accept_memory(start, end) to end+unit_size if + * 'end' is aligned on a unit_size boundary. (immediately following + * this comment) + */ + if (!(end % unit_size)) + end += unit_size; + + /* Make sure not to overrun the bitmap */ + if (end > unaccepted->size * unit_size * BITS_PER_BYTE) + end = unaccepted->size * unit_size * BITS_PER_BYTE; + + range_start = start / unit_size; + + spin_lock_irqsave(&unaccepted_memory_lock, flags); + for_each_set_bitrange_from(range_start, range_end, unaccepted->bitmap, + DIV_ROUND_UP(end, unit_size)) { + unsigned long phys_start, phys_end; + unsigned long len = range_end - range_start; + + phys_start = range_start * unit_size + unaccepted->phys_base; + phys_end = range_end * unit_size + unaccepted->phys_base; + + arch_accept_memory(phys_start, phys_end); + bitmap_clear(unaccepted->bitmap, range_start, len); + } + spin_unlock_irqrestore(&unaccepted_memory_lock, flags); +} + +bool range_contains_unaccepted_memory(phys_addr_t start, phys_addr_t end) +{ + struct efi_unaccepted_memory *unaccepted; + unsigned long flags; + bool ret = false; + u64 unit_size; + + unaccepted = efi_get_unaccepted_table(); + if (!unaccepted) + return false; + + unit_size = unaccepted->unit_size; + + /* + * Only care for the part of the range that is represented + * in the bitmap. + */ + if (start < unaccepted->phys_base) + start = unaccepted->phys_base; + if (end < unaccepted->phys_base) + return false; + + /* Translate to offsets from the beginning of the bitmap */ + start -= unaccepted->phys_base; + end -= unaccepted->phys_base; + + /* + * Also consider the unaccepted state of the *next* page. See fix #1 in + * the comment on load_unaligned_zeropad() in accept_memory(). + */ + if (!(end % unit_size)) + end += unit_size; + + /* Make sure not to overrun the bitmap */ + if (end > unaccepted->size * unit_size * BITS_PER_BYTE) + end = unaccepted->size * unit_size * BITS_PER_BYTE; + + spin_lock_irqsave(&unaccepted_memory_lock, flags); + while (start < end) { + if (test_bit(start / unit_size, unaccepted->bitmap)) { + ret = true; + break; + } + + start += unit_size; + } + spin_unlock_irqrestore(&unaccepted_memory_lock, flags); + + return ret; +} diff --git a/drivers/virt/coco/sev-guest/Kconfig b/drivers/virt/coco/sev-guest/Kconfig index f9db0799ae67..da2d7ca531f0 100644 --- a/drivers/virt/coco/sev-guest/Kconfig +++ b/drivers/virt/coco/sev-guest/Kconfig @@ -2,6 +2,7 @@ config SEV_GUEST tristate "AMD SEV Guest driver" default m depends on AMD_MEM_ENCRYPT + select CRYPTO select CRYPTO_AEAD2 select CRYPTO_GCM help diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c index b43d0bd42762..8dca4d6d96c7 100644 --- a/fs/proc/meminfo.c +++ b/fs/proc/meminfo.c @@ -168,6 +168,11 @@ static int meminfo_proc_show(struct seq_file *m, void *v) global_zone_page_state(NR_FREE_CMA_PAGES)); #endif +#ifdef CONFIG_UNACCEPTED_MEMORY + show_val_kb(m, "Unaccepted: ", + global_zone_page_state(NR_UNACCEPTED)); +#endif + hugetlb_report_meminfo(m); arch_report_meminfo(m); diff --git a/include/linux/efi.h b/include/linux/efi.h index 571d1a6e1b74..18d83a613635 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -108,7 +108,8 @@ typedef struct { #define EFI_MEMORY_MAPPED_IO_PORT_SPACE 12 #define EFI_PAL_CODE 13 #define EFI_PERSISTENT_MEMORY 14 -#define EFI_MAX_MEMORY_TYPE 15 +#define EFI_UNACCEPTED_MEMORY 15 +#define EFI_MAX_MEMORY_TYPE 16 /* Attribute values: */ #define EFI_MEMORY_UC ((u64)0x0000000000000001ULL) /* uncached */ @@ -417,6 +418,7 @@ void efi_native_runtime_setup(void); #define LINUX_EFI_MOK_VARIABLE_TABLE_GUID EFI_GUID(0xc451ed2b, 0x9694, 0x45d3, 0xba, 0xba, 0xed, 0x9f, 0x89, 0x88, 0xa3, 0x89) #define LINUX_EFI_COCO_SECRET_AREA_GUID EFI_GUID(0xadf956ad, 0xe98c, 0x484c, 0xae, 0x11, 0xb5, 0x1c, 0x7d, 0x33, 0x64, 0x47) #define LINUX_EFI_BOOT_MEMMAP_GUID EFI_GUID(0x800f683f, 0xd08b, 0x423a, 0xa2, 0x93, 0x96, 0x5c, 0x3c, 0x6f, 0xe2, 0xb4) +#define LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID EFI_GUID(0xd5d1de3c, 0x105c, 0x44f9, 0x9e, 0xa9, 0xbc, 0xef, 0x98, 0x12, 0x00, 0x31) #define RISCV_EFI_BOOT_PROTOCOL_GUID EFI_GUID(0xccd15fec, 0x6f73, 0x4eec, 0x83, 0x95, 0x3e, 0x69, 0xe4, 0xb9, 0x40, 0xbf) @@ -435,6 +437,9 @@ void efi_native_runtime_setup(void); #define DELLEMC_EFI_RCI2_TABLE_GUID EFI_GUID(0x2d9f28a2, 0xa886, 0x456a, 0x97, 0xa8, 0xf1, 0x1e, 0xf2, 0x4f, 0xf4, 0x55) #define AMD_SEV_MEM_ENCRYPT_GUID EFI_GUID(0x0cf29b71, 0x9e51, 0x433a, 0xa3, 0xb7, 0x81, 0xf3, 0xab, 0x16, 0xb8, 0x75) +/* OVMF protocol GUIDs */ +#define OVMF_SEV_MEMORY_ACCEPTANCE_PROTOCOL_GUID EFI_GUID(0xc5a010fe, 0x38a7, 0x4531, 0x8a, 0x4a, 0x05, 0x00, 0xd2, 0xfd, 0x16, 0x49) + typedef struct { efi_guid_t guid; u64 table; @@ -534,6 +539,14 @@ struct efi_boot_memmap { efi_memory_desc_t map[]; }; +struct efi_unaccepted_memory { + u32 version; + u32 unit_size; + u64 phys_base; + u64 size; + unsigned long bitmap[]; +}; + /* * Architecture independent structure for describing a memory map for the * benefit of efi_memmap_init_early(), and for passing context between @@ -636,6 +649,7 @@ extern struct efi { unsigned long tpm_final_log; /* TPM2 Final Events Log table */ unsigned long mokvar_table; /* MOK variable config table */ unsigned long coco_secret; /* Confidential computing secret table */ + unsigned long unaccepted; /* Unaccepted memory table */ efi_get_time_t *get_time; efi_set_time_t *set_time; diff --git a/include/linux/mm.h b/include/linux/mm.h index 200068d98686..fec149585985 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -3839,4 +3839,23 @@ madvise_set_anon_name(struct mm_struct *mm, unsigned long start, } #endif +#ifdef CONFIG_UNACCEPTED_MEMORY + +bool range_contains_unaccepted_memory(phys_addr_t start, phys_addr_t end); +void accept_memory(phys_addr_t start, phys_addr_t end); + +#else + +static inline bool range_contains_unaccepted_memory(phys_addr_t start, + phys_addr_t end) +{ + return false; +} + +static inline void accept_memory(phys_addr_t start, phys_addr_t end) +{ +} + +#endif + #endif /* _LINUX_MM_H */ diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index a4889c9d4055..6c1c2fc13017 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -143,6 +143,9 @@ enum zone_stat_item { NR_ZSPAGES, /* allocated in zsmalloc */ #endif NR_FREE_CMA_PAGES, +#ifdef CONFIG_UNACCEPTED_MEMORY + NR_UNACCEPTED, +#endif NR_VM_ZONE_STAT_ITEMS }; enum node_stat_item { @@ -910,6 +913,11 @@ struct zone { /* free areas of different sizes */ struct free_area free_area[MAX_ORDER + 1]; +#ifdef CONFIG_UNACCEPTED_MEMORY + /* Pages to be accepted. All pages on the list are MAX_ORDER */ + struct list_head unaccepted_pages; +#endif + /* zone flags, see below */ unsigned long flags; diff --git a/mm/memblock.c b/mm/memblock.c index 3feafea06ab2..50b921119600 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -1436,6 +1436,15 @@ done: */ kmemleak_alloc_phys(found, size, 0); + /* + * Some Virtual Machine platforms, such as Intel TDX or AMD SEV-SNP, + * require memory to be accepted before it can be used by the + * guest. + * + * Accept the memory of the allocated buffer. + */ + accept_memory(found, found + size); + return found; } diff --git a/mm/mm_init.c b/mm/mm_init.c index 7f7f9c677854..1cfc08e25f93 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -1375,6 +1375,10 @@ static void __meminit zone_init_free_lists(struct zone *zone) INIT_LIST_HEAD(&zone->free_area[order].free_list[t]); zone->free_area[order].nr_free = 0; } + +#ifdef CONFIG_UNACCEPTED_MEMORY + INIT_LIST_HEAD(&zone->unaccepted_pages); +#endif } void __meminit init_currently_empty_zone(struct zone *zone, @@ -1960,6 +1964,9 @@ static void __init deferred_free_range(unsigned long pfn, return; } + /* Accept chunks smaller than MAX_ORDER upfront */ + accept_memory(PFN_PHYS(pfn), PFN_PHYS(pfn + nr_pages)); + for (i = 0; i < nr_pages; i++, page++, pfn++) { if (pageblock_aligned(pfn)) set_pageblock_migratetype(page, MIGRATE_MOVABLE); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 47421bedc12b..d239fba3f31c 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -387,6 +387,12 @@ EXPORT_SYMBOL(nr_node_ids); EXPORT_SYMBOL(nr_online_nodes); #endif +static bool page_contains_unaccepted(struct page *page, unsigned int order); +static void accept_page(struct page *page, unsigned int order); +static bool try_to_accept_memory(struct zone *zone, unsigned int order); +static inline bool has_unaccepted_memory(void); +static bool __free_unaccepted(struct page *page); + int page_group_by_mobility_disabled __read_mostly; #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT @@ -1481,6 +1487,13 @@ void __free_pages_core(struct page *page, unsigned int order) atomic_long_add(nr_pages, &page_zone(page)->managed_pages); + if (page_contains_unaccepted(page, order)) { + if (order == MAX_ORDER && __free_unaccepted(page)) + return; + + accept_page(page, order); + } + /* * Bypass PCP and place fresh pages right to the tail, primarily * relevant for memory onlining. @@ -3159,6 +3172,9 @@ static inline long __zone_watermark_unusable_free(struct zone *z, if (!(alloc_flags & ALLOC_CMA)) unusable_free += zone_page_state(z, NR_FREE_CMA_PAGES); #endif +#ifdef CONFIG_UNACCEPTED_MEMORY + unusable_free += zone_page_state(z, NR_UNACCEPTED); +#endif return unusable_free; } @@ -3458,6 +3474,11 @@ retry: gfp_mask)) { int ret; + if (has_unaccepted_memory()) { + if (try_to_accept_memory(zone, order)) + goto try_this_zone; + } + #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT /* * Watermark failed for this zone, but see if we can @@ -3510,6 +3531,11 @@ try_this_zone: return page; } else { + if (has_unaccepted_memory()) { + if (try_to_accept_memory(zone, order)) + goto try_this_zone; + } + #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT /* Try again if zone has deferred pages */ if (deferred_pages_enabled()) { @@ -7215,3 +7241,150 @@ bool has_managed_dma(void) return false; } #endif /* CONFIG_ZONE_DMA */ + +#ifdef CONFIG_UNACCEPTED_MEMORY + +/* Counts number of zones with unaccepted pages. */ +static DEFINE_STATIC_KEY_FALSE(zones_with_unaccepted_pages); + +static bool lazy_accept = true; + +static int __init accept_memory_parse(char *p) +{ + if (!strcmp(p, "lazy")) { + lazy_accept = true; + return 0; + } else if (!strcmp(p, "eager")) { + lazy_accept = false; + return 0; + } else { + return -EINVAL; + } +} +early_param("accept_memory", accept_memory_parse); + +static bool page_contains_unaccepted(struct page *page, unsigned int order) +{ + phys_addr_t start = page_to_phys(page); + phys_addr_t end = start + (PAGE_SIZE << order); + + return range_contains_unaccepted_memory(start, end); +} + +static void accept_page(struct page *page, unsigned int order) +{ + phys_addr_t start = page_to_phys(page); + + accept_memory(start, start + (PAGE_SIZE << order)); +} + +static bool try_to_accept_memory_one(struct zone *zone) +{ + unsigned long flags; + struct page *page; + bool last; + + if (list_empty(&zone->unaccepted_pages)) + return false; + + spin_lock_irqsave(&zone->lock, flags); + page = list_first_entry_or_null(&zone->unaccepted_pages, + struct page, lru); + if (!page) { + spin_unlock_irqrestore(&zone->lock, flags); + return false; + } + + list_del(&page->lru); + last = list_empty(&zone->unaccepted_pages); + + __mod_zone_freepage_state(zone, -MAX_ORDER_NR_PAGES, MIGRATE_MOVABLE); + __mod_zone_page_state(zone, NR_UNACCEPTED, -MAX_ORDER_NR_PAGES); + spin_unlock_irqrestore(&zone->lock, flags); + + accept_page(page, MAX_ORDER); + + __free_pages_ok(page, MAX_ORDER, FPI_TO_TAIL); + + if (last) + static_branch_dec(&zones_with_unaccepted_pages); + + return true; +} + +static bool try_to_accept_memory(struct zone *zone, unsigned int order) +{ + long to_accept; + int ret = false; + + /* How much to accept to get to high watermark? */ + to_accept = high_wmark_pages(zone) - + (zone_page_state(zone, NR_FREE_PAGES) - + __zone_watermark_unusable_free(zone, order, 0)); + + /* Accept at least one page */ + do { + if (!try_to_accept_memory_one(zone)) + break; + ret = true; + to_accept -= MAX_ORDER_NR_PAGES; + } while (to_accept > 0); + + return ret; +} + +static inline bool has_unaccepted_memory(void) +{ + return static_branch_unlikely(&zones_with_unaccepted_pages); +} + +static bool __free_unaccepted(struct page *page) +{ + struct zone *zone = page_zone(page); + unsigned long flags; + bool first = false; + + if (!lazy_accept) + return false; + + spin_lock_irqsave(&zone->lock, flags); + first = list_empty(&zone->unaccepted_pages); + list_add_tail(&page->lru, &zone->unaccepted_pages); + __mod_zone_freepage_state(zone, MAX_ORDER_NR_PAGES, MIGRATE_MOVABLE); + __mod_zone_page_state(zone, NR_UNACCEPTED, MAX_ORDER_NR_PAGES); + spin_unlock_irqrestore(&zone->lock, flags); + + if (first) + static_branch_inc(&zones_with_unaccepted_pages); + + return true; +} + +#else + +static bool page_contains_unaccepted(struct page *page, unsigned int order) +{ + return false; +} + +static void accept_page(struct page *page, unsigned int order) +{ +} + +static bool try_to_accept_memory(struct zone *zone, unsigned int order) +{ + return false; +} + +static inline bool has_unaccepted_memory(void) +{ + return false; +} + +static bool __free_unaccepted(struct page *page) +{ + BUILD_BUG(); + return false; +} + +#endif /* CONFIG_UNACCEPTED_MEMORY */ diff --git a/mm/vmstat.c b/mm/vmstat.c index c28046371b45..282349cabf01 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -1180,6 +1180,9 @@ const char * const vmstat_text[] = { "nr_zspages", #endif "nr_free_cma", +#ifdef CONFIG_UNACCEPTED_MEMORY + "nr_unaccepted", +#endif /* enum numa_stat_item counters */ #ifdef CONFIG_NUMA |