arch/x86/kernel/head64.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  prepare to run common code
   4  *
   5  *  Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
   6  */
   7
   8 #define DISABLE_BRANCH_PROFILING
   9
  10 /* cpu_feature_enabled() cannot be used this early */
  11 #define USE_EARLY_PGTABLE_L5
  12
  13 #include <linux/init.h>
  14 #include <linux/linkage.h>
  15 #include <linux/types.h>
  16 #include <linux/kernel.h>
  17 #include <linux/string.h>
  18 #include <linux/percpu.h>
  19 #include <linux/start_kernel.h>
  20 #include <linux/io.h>
  21 #include <linux/memblock.h>
  22 #include <linux/mem_encrypt.h>
  23 #include <linux/pgtable.h>
  24
  25 #include <asm/processor.h>
  26 #include <asm/proto.h>
  27 #include <asm/smp.h>
  28 #include <asm/setup.h>
  29 #include <asm/desc.h>
  30 #include <asm/tlbflush.h>
  31 #include <asm/sections.h>
  32 #include <asm/kdebug.h>
  33 #include <asm/e820/api.h>
  34 #include <asm/bios_ebda.h>
  35 #include <asm/bootparam_utils.h>
  36 #include <asm/microcode.h>
  37 #include <asm/kasan.h>
  38 #include <asm/fixmap.h>
  39 #include <asm/realmode.h>
  40 #include <asm/desc.h>
  41 #include <asm/extable.h>
  42 #include <asm/trapnr.h>
  43 #include <asm/sev-es.h>
  44
  45 /*
  46  * Manage page tables very early on.
  47  */
  48 extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD];
  49 static unsigned int __initdata next_early_pgt;
  50 pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX);
  51
  52 #ifdef CONFIG_X86_5LEVEL
  53 unsigned int __pgtable_l5_enabled __ro_after_init;
  54 unsigned int pgdir_shift __ro_after_init = 39;
  55 EXPORT_SYMBOL(pgdir_shift);
  56 unsigned int ptrs_per_p4d __ro_after_init = 1;
  57 EXPORT_SYMBOL(ptrs_per_p4d);
  58 #endif
  59
  60 #ifdef CONFIG_DYNAMIC_MEMORY_LAYOUT
  61 unsigned long page_offset_base __ro_after_init = __PAGE_OFFSET_BASE_L4;
  62 EXPORT_SYMBOL(page_offset_base);
  63 unsigned long vmalloc_base __ro_after_init = __VMALLOC_BASE_L4;
  64 EXPORT_SYMBOL(vmalloc_base);
  65 unsigned long vmemmap_base __ro_after_init = __VMEMMAP_BASE_L4;
  66 EXPORT_SYMBOL(vmemmap_base);
  67 #endif
  68
  69 /*
  70  * GDT used on the boot CPU before switching to virtual addresses.
  71  */
  72 static struct desc_struct startup_gdt[GDT_ENTRIES] = {
  73         [GDT_ENTRY_KERNEL32_CS]         = GDT_ENTRY_INIT(0xc09b, 0, 0xfffff),
  74         [GDT_ENTRY_KERNEL_CS]           = GDT_ENTRY_INIT(0xa09b, 0, 0xfffff),
  75         [GDT_ENTRY_KERNEL_DS]           = GDT_ENTRY_INIT(0xc093, 0, 0xfffff),
  76 };
  77
  78 /*
  79  * Address needs to be set at runtime because it references the startup_gdt
  80  * while the kernel still uses a direct mapping.
  81  */
  82 static struct desc_ptr startup_gdt_descr = {
  83         .size = sizeof(startup_gdt)-1,
  84         .address = 0,
  85 };
  86
  87 #define __head  __section(".head.text")
  88
  89 static void __head *fixup_pointer(void *ptr, unsigned long physaddr)
  90 {
  91         return ptr - (void *)_text + (void *)physaddr;
  92 }
  93
  94 static unsigned long __head *fixup_long(void *ptr, unsigned long physaddr)
  95 {
  96         return fixup_pointer(ptr, physaddr);
  97 }
  98
  99 #ifdef CONFIG_X86_5LEVEL
 100 static unsigned int __head *fixup_int(void *ptr, unsigned long physaddr)
 101 {
 102         return fixup_pointer(ptr, physaddr);
 103 }
 104
 105 static bool __head check_la57_support(unsigned long physaddr)
 106 {
 107         /*
 108          * 5-level paging is detected and enabled at kernel decomression
 109          * stage. Only check if it has been enabled there.
 110          */
 111         if (!(native_read_cr4() & X86_CR4_LA57))
 112                 return false;
 113
 114         *fixup_int(&__pgtable_l5_enabled, physaddr) = 1;
 115         *fixup_int(&pgdir_shift, physaddr) = 48;
 116         *fixup_int(&ptrs_per_p4d, physaddr) = 512;
 117         *fixup_long(&page_offset_base, physaddr) = __PAGE_OFFSET_BASE_L5;
 118         *fixup_long(&vmalloc_base, physaddr) = __VMALLOC_BASE_L5;
 119         *fixup_long(&vmemmap_base, physaddr) = __VMEMMAP_BASE_L5;
 120
 121         return true;
 122 }
 123 #else
 124 static bool __head check_la57_support(unsigned long physaddr)
 125 {
 126         return false;
 127 }
 128 #endif
 129
 130 /* Code in __startup_64() can be relocated during execution, but the compiler
 131  * doesn't have to generate PC-relative relocations when accessing globals from
 132  * that function. Clang actually does not generate them, which leads to
 133  * boot-time crashes. To work around this problem, every global pointer must
 134  * be adjusted using fixup_pointer().
 135  */
 136 unsigned long __head __startup_64(unsigned long physaddr,
 137                                   struct boot_params *bp)
 138 {
 139         unsigned long vaddr, vaddr_end;
 140         unsigned long load_delta, *p;
 141         unsigned long pgtable_flags;
 142         pgdval_t *pgd;
 143         p4dval_t *p4d;
 144         pudval_t *pud;
 145         pmdval_t *pmd, pmd_entry;
 146         pteval_t *mask_ptr;
 147         bool la57;
 148         int i;
 149         unsigned int *next_pgt_ptr;
 150
 151         la57 = check_la57_support(physaddr);
 152
 153         /* Is the address too large? */
 154         if (physaddr >> MAX_PHYSMEM_BITS)
 155                 for (;;);
 156
 157         /*
 158          * Compute the delta between the address I am compiled to run at
 159          * and the address I am actually running at.
 160          */
 161         load_delta = physaddr - (unsigned long)(_text - __START_KERNEL_map);
 162
 163         /* Is the address not 2M aligned? */
 164         if (load_delta & ~PMD_PAGE_MASK)
 165                 for (;;);
 166
 167         /* Activate Secure Memory Encryption (SME) if supported and enabled */
 168         sme_enable(bp);
 169
 170         /* Include the SME encryption mask in the fixup value */
 171         load_delta += sme_get_me_mask();
 172
 173         /* Fixup the physical addresses in the page table */
 174
 175         pgd = fixup_pointer(&early_top_pgt, physaddr);
 176         p = pgd + pgd_index(__START_KERNEL_map);
 177         if (la57)
 178                 *p = (unsigned long)level4_kernel_pgt;
 179         else
 180                 *p = (unsigned long)level3_kernel_pgt;
 181         *p += _PAGE_TABLE_NOENC - __START_KERNEL_map + load_delta;
 182
 183         if (la57) {
 184                 p4d = fixup_pointer(&level4_kernel_pgt, physaddr);
 185                 p4d[511] += load_delta;
 186         }
 187
 188         pud = fixup_pointer(&level3_kernel_pgt, physaddr);
 189         pud[510] += load_delta;
 190         pud[511] += load_delta;
 191
 192         pmd = fixup_pointer(level2_fixmap_pgt, physaddr);
 193         for (i = FIXMAP_PMD_TOP; i > FIXMAP_PMD_TOP - FIXMAP_PMD_NUM; i--)
 194                 pmd[i] += load_delta;
 195
 196         /*
 197          * Set up the identity mapping for the switchover.  These
 198          * entries should *NOT* have the global bit set!  This also
 199          * creates a bunch of nonsense entries but that is fine --
 200          * it avoids problems around wraparound.
 201          */
 202
 203         next_pgt_ptr = fixup_pointer(&next_early_pgt, physaddr);
 204         pud = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++], physaddr);
 205         pmd = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++], physaddr);
 206
 207         pgtable_flags = _KERNPG_TABLE_NOENC + sme_get_me_mask();
 208
 209         if (la57) {
 210                 p4d = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++],
 211                                     physaddr);
 212
 213                 i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD;
 214                 pgd[i + 0] = (pgdval_t)p4d + pgtable_flags;
 215                 pgd[i + 1] = (pgdval_t)p4d + pgtable_flags;
 216
 217                 i = physaddr >> P4D_SHIFT;
 218                 p4d[(i + 0) % PTRS_PER_P4D] = (pgdval_t)pud + pgtable_flags;
 219                 p4d[(i + 1) % PTRS_PER_P4D] = (pgdval_t)pud + pgtable_flags;
 220         } else {
 221                 i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD;
 222                 pgd[i + 0] = (pgdval_t)pud + pgtable_flags;
 223                 pgd[i + 1] = (pgdval_t)pud + pgtable_flags;
 224         }
 225
 226         i = physaddr >> PUD_SHIFT;
 227         pud[(i + 0) % PTRS_PER_PUD] = (pudval_t)pmd + pgtable_flags;
 228         pud[(i + 1) % PTRS_PER_PUD] = (pudval_t)pmd + pgtable_flags;
 229
 230         pmd_entry = __PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL;
 231         /* Filter out unsupported __PAGE_KERNEL_* bits: */
 232         mask_ptr = fixup_pointer(&__supported_pte_mask, physaddr);
 233         pmd_entry &= *mask_ptr;
 234         pmd_entry += sme_get_me_mask();
 235         pmd_entry +=  physaddr;
 236
 237         for (i = 0; i < DIV_ROUND_UP(_end - _text, PMD_SIZE); i++) {
 238                 int idx = i + (physaddr >> PMD_SHIFT);
 239
 240                 pmd[idx % PTRS_PER_PMD] = pmd_entry + i * PMD_SIZE;
 241         }
 242
 243         /*
 244          * Fixup the kernel text+data virtual addresses. Note that
 245          * we might write invalid pmds, when the kernel is relocated
 246          * cleanup_highmap() fixes this up along with the mappings
 247          * beyond _end.
 248          *
 249          * Only the region occupied by the kernel image has so far
 250          * been checked against the table of usable memory regions
 251          * provided by the firmware, so invalidate pages outside that
 252          * region. A page table entry that maps to a reserved area of
 253          * memory would allow processor speculation into that area,
 254          * and on some hardware (particularly the UV platform) even
 255          * speculative access to some reserved areas is caught as an
 256          * error, causing the BIOS to halt the system.
 257          */
 258
 259         pmd = fixup_pointer(level2_kernel_pgt, physaddr);
 260
 261         /* invalidate pages before the kernel image */
 262         for (i = 0; i < pmd_index((unsigned long)_text); i++)
 263                 pmd[i] &= ~_PAGE_PRESENT;
 264
 265         /* fixup pages that are part of the kernel image */
 266         for (; i <= pmd_index((unsigned long)_end); i++)
 267                 if (pmd[i] & _PAGE_PRESENT)
 268                         pmd[i] += load_delta;
 269
 270         /* invalidate pages after the kernel image */
 271         for (; i < PTRS_PER_PMD; i++)
 272                 pmd[i] &= ~_PAGE_PRESENT;
 273
 274         /*
 275          * Fixup phys_base - remove the memory encryption mask to obtain
 276          * the true physical address.
 277          */
 278         *fixup_long(&phys_base, physaddr) += load_delta - sme_get_me_mask();
 279
 280         /* Encrypt the kernel and related (if SME is active) */
 281         sme_encrypt_kernel(bp);
 282
 283         /*
 284          * Clear the memory encryption mask from the .bss..decrypted section.
 285          * The bss section will be memset to zero later in the initialization so
 286          * there is no need to zero it after changing the memory encryption
 287          * attribute.
 288          */
 289         if (mem_encrypt_active()) {
 290                 vaddr = (unsigned long)__start_bss_decrypted;
 291                 vaddr_end = (unsigned long)__end_bss_decrypted;
 292                 for (; vaddr < vaddr_end; vaddr += PMD_SIZE) {
 293                         i = pmd_index(vaddr);
 294                         pmd[i] -= sme_get_me_mask();
 295                 }
 296         }
 297
 298         /*
 299          * Return the SME encryption mask (if SME is active) to be used as a
 300          * modifier for the initial pgdir entry programmed into CR3.
 301          */
 302         return sme_get_me_mask();
 303 }
 304
 305 /* Wipe all early page tables except for the kernel symbol map */
 306 static void __init reset_early_page_tables(void)
 307 {
 308         memset(early_top_pgt, 0, sizeof(pgd_t)*(PTRS_PER_PGD-1));
 309         next_early_pgt = 0;
 310         write_cr3(__sme_pa_nodebug(early_top_pgt));
 311 }
 312
 313 /* Create a new PMD entry */
 314 bool __init __early_make_pgtable(unsigned long address, pmdval_t pmd)
 315 {
 316         unsigned long physaddr = address - __PAGE_OFFSET;
 317         pgdval_t pgd, *pgd_p;
 318         p4dval_t p4d, *p4d_p;
 319         pudval_t pud, *pud_p;
 320         pmdval_t *pmd_p;
 321
 322         /* Invalid address or early pgt is done ?  */
 323         if (physaddr >= MAXMEM || read_cr3_pa() != __pa_nodebug(early_top_pgt))
 324                 return false;
 325
 326 again:
 327         pgd_p = &early_top_pgt[pgd_index(address)].pgd;
 328         pgd = *pgd_p;
 329
 330         /*
 331          * The use of __START_KERNEL_map rather than __PAGE_OFFSET here is
 332          * critical -- __PAGE_OFFSET would point us back into the dynamic
 333          * range and we might end up looping forever...
 334          */
 335         if (!pgtable_l5_enabled())
 336                 p4d_p = pgd_p;
 337         else if (pgd)
 338                 p4d_p = (p4dval_t *)((pgd & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
 339         else {
 340                 if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) {
 341                         reset_early_page_tables();
 342                         goto again;
 343                 }
 344
 345                 p4d_p = (p4dval_t *)early_dynamic_pgts[next_early_pgt++];
 346                 memset(p4d_p, 0, sizeof(*p4d_p) * PTRS_PER_P4D);
 347                 *pgd_p = (pgdval_t)p4d_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
 348         }
 349         p4d_p += p4d_index(address);
 350         p4d = *p4d_p;
 351
 352         if (p4d)
 353                 pud_p = (pudval_t *)((p4d & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
 354         else {
 355                 if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) {
 356                         reset_early_page_tables();
 357                         goto again;
 358                 }
 359
 360                 pud_p = (pudval_t *)early_dynamic_pgts[next_early_pgt++];
 361                 memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
 362                 *p4d_p = (p4dval_t)pud_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
 363         }
 364         pud_p += pud_index(address);
 365         pud = *pud_p;
 366
 367         if (pud)
 368                 pmd_p = (pmdval_t *)((pud & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
 369         else {
 370                 if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) {
 371                         reset_early_page_tables();
 372                         goto again;
 373                 }
 374
 375                 pmd_p = (pmdval_t *)early_dynamic_pgts[next_early_pgt++];
 376                 memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD);
 377                 *pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
 378         }
 379         pmd_p[pmd_index(address)] = pmd;
 380
 381         return true;
 382 }
 383
 384 static bool __init early_make_pgtable(unsigned long address)
 385 {
 386         unsigned long physaddr = address - __PAGE_OFFSET;
 387         pmdval_t pmd;
 388
 389         pmd = (physaddr & PMD_MASK) + early_pmd_flags;
 390
 391         return __early_make_pgtable(address, pmd);
 392 }
 393
 394 void __init do_early_exception(struct pt_regs *regs, int trapnr)
 395 {
 396         if (trapnr == X86_TRAP_PF &&
 397             early_make_pgtable(native_read_cr2()))
 398                 return;
 399
 400         if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT) &&
 401             trapnr == X86_TRAP_VC && handle_vc_boot_ghcb(regs))
 402                 return;
 403
 404         early_fixup_exception(regs, trapnr);
 405 }
 406
 407 /* Don't add a printk in there. printk relies on the PDA which is not initialized
 408    yet. */
 409 static void __init clear_bss(void)
 410 {
 411         memset(__bss_start, 0,
 412                (unsigned long) __bss_stop - (unsigned long) __bss_start);
 413         memset(__brk_base, 0,
 414                (unsigned long) __brk_limit - (unsigned long) __brk_base);
 415 }
 416
 417 static unsigned long get_cmd_line_ptr(void)
 418 {
 419         unsigned long cmd_line_ptr = boot_params.hdr.cmd_line_ptr;
 420
 421         cmd_line_ptr |= (u64)boot_params.ext_cmd_line_ptr << 32;
 422
 423         return cmd_line_ptr;
 424 }
 425
 426 static void __init copy_bootdata(char *real_mode_data)
 427 {
 428         char * command_line;
 429         unsigned long cmd_line_ptr;
 430
 431         /*
 432          * If SME is active, this will create decrypted mappings of the
 433          * boot data in advance of the copy operations.
 434          */
 435         sme_map_bootdata(real_mode_data);
 436
 437         memcpy(&boot_params, real_mode_data, sizeof(boot_params));
 438         sanitize_boot_params(&boot_params);
 439         cmd_line_ptr = get_cmd_line_ptr();
 440         if (cmd_line_ptr) {
 441                 command_line = __va(cmd_line_ptr);
 442                 memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
 443         }
 444
 445         /*
 446          * The old boot data is no longer needed and won't be reserved,
 447          * freeing up that memory for use by the system. If SME is active,
 448          * we need to remove the mappings that were created so that the
 449          * memory doesn't remain mapped as decrypted.
 450          */
 451         sme_unmap_bootdata(real_mode_data);
 452 }
 453
 454 asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data)
 455 {
 456         /*
 457          * Build-time sanity checks on the kernel image and module
 458          * area mappings. (these are purely build-time and produce no code)
 459          */
 460         BUILD_BUG_ON(MODULES_VADDR < __START_KERNEL_map);
 461         BUILD_BUG_ON(MODULES_VADDR - __START_KERNEL_map < KERNEL_IMAGE_SIZE);
 462         BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE);
 463         BUILD_BUG_ON((__START_KERNEL_map & ~PMD_MASK) != 0);
 464         BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0);
 465         BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL));
 466         MAYBE_BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
 467                                 (__START_KERNEL & PGDIR_MASK)));
 468         BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END);
 469
 470         cr4_init_shadow();
 471
 472         /* Kill off the identity-map trampoline */
 473         reset_early_page_tables();
 474
 475         clear_bss();
 476
 477         clear_page(init_top_pgt);
 478
 479         /*
 480          * SME support may update early_pmd_flags to include the memory
 481          * encryption mask, so it needs to be called before anything
 482          * that may generate a page fault.
 483          */
 484         sme_early_init();
 485
 486         kasan_early_init();
 487
 488         idt_setup_early_handler();
 489
 490         copy_bootdata(__va(real_mode_data));
 491
 492         /*
 493          * Load microcode early on BSP.
 494          */
 495         load_ucode_bsp();
 496
 497         /* set init_top_pgt kernel high mapping*/
 498         init_top_pgt[511] = early_top_pgt[511];
 499
 500         x86_64_start_reservations(real_mode_data);
 501 }
 502
 503 void __init x86_64_start_reservations(char *real_mode_data)
 504 {
 505         /* version is always not zero if it is copied */
 506         if (!boot_params.hdr.version)
 507                 copy_bootdata(__va(real_mode_data));
 508
 509         x86_early_init_platform_quirks();
 510
 511         switch (boot_params.hdr.hardware_subarch) {
 512         case X86_SUBARCH_INTEL_MID:
 513                 x86_intel_mid_early_setup();
 514                 break;
 515         default:
 516                 break;
 517         }
 518
 519         start_kernel();
 520 }
 521
 522 /*
 523  * Data structures and code used for IDT setup in head_64.S. The bringup-IDT is
 524  * used until the idt_table takes over. On the boot CPU this happens in
 525  * x86_64_start_kernel(), on secondary CPUs in start_secondary(). In both cases
 526  * this happens in the functions called from head_64.S.
 527  *
 528  * The idt_table can't be used that early because all the code modifying it is
 529  * in idt.c and can be instrumented by tracing or KASAN, which both don't work
 530  * during early CPU bringup. Also the idt_table has the runtime vectors
 531  * configured which require certain CPU state to be setup already (like TSS),
 532  * which also hasn't happened yet in early CPU bringup.
 533  */
 534 static gate_desc bringup_idt_table[NUM_EXCEPTION_VECTORS] __page_aligned_data;
 535
 536 static struct desc_ptr bringup_idt_descr = {
 537         .size           = (NUM_EXCEPTION_VECTORS * sizeof(gate_desc)) - 1,
 538         .address        = 0, /* Set at runtime */
 539 };
 540
 541 static void set_bringup_idt_handler(gate_desc *idt, int n, void *handler)
 542 {
 543 #ifdef CONFIG_AMD_MEM_ENCRYPT
 544         struct idt_data data;
 545         gate_desc desc;
 546
 547         init_idt_data(&data, n, handler);
 548         idt_init_desc(&desc, &data);
 549         native_write_idt_entry(idt, n, &desc);
 550 #endif
 551 }
 552
 553 /* This runs while still in the direct mapping */
 554 static void startup_64_load_idt(unsigned long physbase)
 555 {
 556         struct desc_ptr *desc = fixup_pointer(&bringup_idt_descr, physbase);
 557         gate_desc *idt = fixup_pointer(bringup_idt_table, physbase);
 558
 559
 560         if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {
 561                 void *handler;
 562
 563                 /* VMM Communication Exception */
 564                 handler = fixup_pointer(vc_no_ghcb, physbase);
 565                 set_bringup_idt_handler(idt, X86_TRAP_VC, handler);
 566         }
 567
 568         desc->address = (unsigned long)idt;
 569         native_load_idt(desc);
 570 }
 571
 572 /* This is used when running on kernel addresses */
 573 void early_setup_idt(void)
 574 {
 575         /* VMM Communication Exception */
 576         if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT))
 577                 set_bringup_idt_handler(bringup_idt_table, X86_TRAP_VC, vc_boot_ghcb);
 578
 579         bringup_idt_descr.address = (unsigned long)bringup_idt_table;
 580         native_load_idt(&bringup_idt_descr);
 581 }
 582
 583 /*
 584  * Setup boot CPU state needed before kernel switches to virtual addresses.
 585  */
 586 void __head startup_64_setup_env(unsigned long physbase)
 587 {
 588         /* Load GDT */
 589         startup_gdt_descr.address = (unsigned long)fixup_pointer(startup_gdt, physbase);
 590         native_load_gdt(&startup_gdt_descr);
 591
 592         /* New GDT is live - reload data segment registers */
 593         asm volatile("movl %%eax, %%ds\n"
 594                      "movl %%eax, %%ss\n"
 595                      "movl %%eax, %%es\n" : : "a"(__KERNEL_DS) : "memory");
 596
 597         startup_64_load_idt(physbase);
 598 }