arch/x86/include/asm/sev.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * AMD Encrypted Register State Support
   4  *
   5  * Author: Joerg Roedel <jroedel@suse.de>
   6  */
   7
   8 #ifndef __ASM_ENCRYPTED_STATE_H
   9 #define __ASM_ENCRYPTED_STATE_H
  10
  11 #include <linux/types.h>
  12 #include <linux/sev-guest.h>
  13
  14 #include <asm/insn.h>
  15 #include <asm/sev-common.h>
  16 #include <asm/bootparam.h>
  17 #include <asm/coco.h>
  18
  19 #define GHCB_PROTOCOL_MIN       1ULL
  20 #define GHCB_PROTOCOL_MAX       2ULL
  21 #define GHCB_DEFAULT_USAGE      0ULL
  22
  23 #define VMGEXIT()                       { asm volatile("rep; vmmcall\n\r"); }
  24
  25 enum es_result {
  26         ES_OK,                  /* All good */
  27         ES_UNSUPPORTED,         /* Requested operation not supported */
  28         ES_VMM_ERROR,           /* Unexpected state from the VMM */
  29         ES_DECODE_FAILED,       /* Instruction decoding failed */
  30         ES_EXCEPTION,           /* Instruction caused exception */
  31         ES_RETRY,               /* Retry instruction emulation */
  32 };
  33
  34 struct es_fault_info {
  35         unsigned long vector;
  36         unsigned long error_code;
  37         unsigned long cr2;
  38 };
  39
  40 struct pt_regs;
  41
  42 /* ES instruction emulation context */
  43 struct es_em_ctxt {
  44         struct pt_regs *regs;
  45         struct insn insn;
  46         struct es_fault_info fi;
  47 };
  48
  49 /*
  50  * AMD SEV Confidential computing blob structure. The structure is
  51  * defined in OVMF UEFI firmware header:
  52  * https://github.com/tianocore/edk2/blob/master/OvmfPkg/Include/Guid/ConfidentialComputingSevSnpBlob.h
  53  */
  54 #define CC_BLOB_SEV_HDR_MAGIC   0x45444d41
  55 struct cc_blob_sev_info {
  56         u32 magic;
  57         u16 version;
  58         u16 reserved;
  59         u64 secrets_phys;
  60         u32 secrets_len;
  61         u32 rsvd1;
  62         u64 cpuid_phys;
  63         u32 cpuid_len;
  64         u32 rsvd2;
  65 } __packed;
  66
  67 void do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code);
  68
  69 static inline u64 lower_bits(u64 val, unsigned int bits)
  70 {
  71         u64 mask = (1ULL << bits) - 1;
  72
  73         return (val & mask);
  74 }
  75
  76 struct real_mode_header;
  77 enum stack_type;
  78
  79 /* Early IDT entry points for #VC handler */
  80 extern void vc_no_ghcb(void);
  81 extern void vc_boot_ghcb(void);
  82 extern bool handle_vc_boot_ghcb(struct pt_regs *regs);
  83
  84 /* PVALIDATE return codes */
  85 #define PVALIDATE_FAIL_SIZEMISMATCH     6
  86
  87 /* Software defined (when rFlags.CF = 1) */
  88 #define PVALIDATE_FAIL_NOUPDATE         255
  89
  90 /* RMP page size */
  91 #define RMP_PG_SIZE_4K                  0
  92 #define RMP_PG_SIZE_2M                  1
  93
  94 #define RMPADJUST_VMSA_PAGE_BIT         BIT(16)
  95
  96 /* SNP Guest message request */
  97 struct snp_req_data {
  98         unsigned long req_gpa;
  99         unsigned long resp_gpa;
 100         unsigned long data_gpa;
 101         unsigned int data_npages;
 102 };
 103
 104 struct sev_guest_platform_data {
 105         u64 secrets_gpa;
 106 };
 107
 108 /*
 109  * The secrets page contains 96-bytes of reserved field that can be used by
 110  * the guest OS. The guest OS uses the area to save the message sequence
 111  * number for each VMPCK.
 112  *
 113  * See the GHCB spec section Secret page layout for the format for this area.
 114  */
 115 struct secrets_os_area {
 116         u32 msg_seqno_0;
 117         u32 msg_seqno_1;
 118         u32 msg_seqno_2;
 119         u32 msg_seqno_3;
 120         u64 ap_jump_table_pa;
 121         u8 rsvd[40];
 122         u8 guest_usage[32];
 123 } __packed;
 124
 125 #define VMPCK_KEY_LEN           32
 126
 127 /* See the SNP spec version 0.9 for secrets page format */
 128 struct snp_secrets_page_layout {
 129         u32 version;
 130         u32 imien       : 1,
 131             rsvd1       : 31;
 132         u32 fms;
 133         u32 rsvd2;
 134         u8 gosvw[16];
 135         u8 vmpck0[VMPCK_KEY_LEN];
 136         u8 vmpck1[VMPCK_KEY_LEN];
 137         u8 vmpck2[VMPCK_KEY_LEN];
 138         u8 vmpck3[VMPCK_KEY_LEN];
 139         struct secrets_os_area os_area;
 140         u8 rsvd3[3840];
 141 } __packed;
 142
 143 #ifdef CONFIG_AMD_MEM_ENCRYPT
 144 extern void __sev_es_ist_enter(struct pt_regs *regs);
 145 extern void __sev_es_ist_exit(void);
 146 static __always_inline void sev_es_ist_enter(struct pt_regs *regs)
 147 {
 148         if (cc_vendor == CC_VENDOR_AMD &&
 149             cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
 150                 __sev_es_ist_enter(regs);
 151 }
 152 static __always_inline void sev_es_ist_exit(void)
 153 {
 154         if (cc_vendor == CC_VENDOR_AMD &&
 155             cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
 156                 __sev_es_ist_exit();
 157 }
 158 extern int sev_es_setup_ap_jump_table(struct real_mode_header *rmh);
 159 extern void __sev_es_nmi_complete(void);
 160 static __always_inline void sev_es_nmi_complete(void)
 161 {
 162         if (cc_vendor == CC_VENDOR_AMD &&
 163             cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
 164                 __sev_es_nmi_complete();
 165 }
 166 extern int __init sev_es_efi_map_ghcbs(pgd_t *pgd);
 167 extern void sev_enable(struct boot_params *bp);
 168
 169 static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs)
 170 {
 171         int rc;
 172
 173         /* "rmpadjust" mnemonic support in binutils 2.36 and newer */
 174         asm volatile(".byte 0xF3,0x0F,0x01,0xFE\n\t"
 175                      : "=a"(rc)
 176                      : "a"(vaddr), "c"(rmp_psize), "d"(attrs)
 177                      : "memory", "cc");
 178
 179         return rc;
 180 }
 181 static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate)
 182 {
 183         bool no_rmpupdate;
 184         int rc;
 185
 186         /* "pvalidate" mnemonic support in binutils 2.36 and newer */
 187         asm volatile(".byte 0xF2, 0x0F, 0x01, 0xFF\n\t"
 188                      CC_SET(c)
 189                      : CC_OUT(c) (no_rmpupdate), "=a"(rc)
 190                      : "a"(vaddr), "c"(rmp_psize), "d"(validate)
 191                      : "memory", "cc");
 192
 193         if (no_rmpupdate)
 194                 return PVALIDATE_FAIL_NOUPDATE;
 195
 196         return rc;
 197 }
 198
 199 struct snp_guest_request_ioctl;
 200
 201 void setup_ghcb(void);
 202 void early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
 203                                   unsigned long npages);
 204 void early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr,
 205                                  unsigned long npages);
 206 void snp_set_memory_shared(unsigned long vaddr, unsigned long npages);
 207 void snp_set_memory_private(unsigned long vaddr, unsigned long npages);
 208 void snp_set_wakeup_secondary_cpu(void);
 209 bool snp_init(struct boot_params *bp);
 210 void __noreturn snp_abort(void);
 211 void snp_dmi_setup(void);
 212 int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio);
 213 void snp_accept_memory(phys_addr_t start, phys_addr_t end);
 214 u64 snp_get_unsupported_features(u64 status);
 215 u64 sev_get_status(void);
 216 #else
 217 static inline void sev_es_ist_enter(struct pt_regs *regs) { }
 218 static inline void sev_es_ist_exit(void) { }
 219 static inline int sev_es_setup_ap_jump_table(struct real_mode_header *rmh) { return 0; }
 220 static inline void sev_es_nmi_complete(void) { }
 221 static inline int sev_es_efi_map_ghcbs(pgd_t *pgd) { return 0; }
 222 static inline void sev_enable(struct boot_params *bp) { }
 223 static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate) { return 0; }
 224 static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs) { return 0; }
 225 static inline void setup_ghcb(void) { }
 226 static inline void __init
 227 early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr, unsigned long npages) { }
 228 static inline void __init
 229 early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr, unsigned long npages) { }
 230 static inline void snp_set_memory_shared(unsigned long vaddr, unsigned long npages) { }
 231 static inline void snp_set_memory_private(unsigned long vaddr, unsigned long npages) { }
 232 static inline void snp_set_wakeup_secondary_cpu(void) { }
 233 static inline bool snp_init(struct boot_params *bp) { return false; }
 234 static inline void snp_abort(void) { }
 235 static inline void snp_dmi_setup(void) { }
 236 static inline int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio)
 237 {
 238         return -ENOTTY;
 239 }
 240
 241 static inline void snp_accept_memory(phys_addr_t start, phys_addr_t end) { }
 242 static inline u64 snp_get_unsupported_features(u64 status) { return 0; }
 243 static inline u64 sev_get_status(void) { return 0; }
 244 #endif
 245
 246 #endif