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 <[email protected]> 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/cc_platform.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/extable.h>
  41 #include <asm/trapnr.h>
  42 #include <asm/sev.h>
  43
  44 /*
  45  * Manage page tables very early on.
  46  */
  47 extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD];
  48 static unsigned int __initdata next_early_pgt;
  49 pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX);
  50
  51 #ifdef CONFIG_X86_5LEVEL
  52 unsigned int __pgtable_l5_enabled __ro_after_init;
  53 unsigned int pgdir_shift __ro_after_init = 39;
  54 EXPORT_SYMBOL(pgdir_shift);
  55 unsigned int ptrs_per_p4d __ro_after_init = 1;
  56 EXPORT_SYMBOL(ptrs_per_p4d);
  57 #endif
  58
  59 #ifdef CONFIG_DYNAMIC_MEMORY_LAYOUT
  60 unsigned long page_offset_base __ro_after_init = __PAGE_OFFSET_BASE_L4;
  61 EXPORT_SYMBOL(page_offset_base);
  62 unsigned long vmalloc_base __ro_after_init = __VMALLOC_BASE_L4;
  63 EXPORT_SYMBOL(vmalloc_base);
  64 unsigned long vmemmap_base __ro_after_init = __VMEMMAP_BASE_L4;
  65 EXPORT_SYMBOL(vmemmap_base);
  66 #endif
  67
  68 /*
  69  * GDT used on the boot CPU before switching to virtual addresses.
  70  */
  71 static struct desc_struct startup_gdt[GDT_ENTRIES] = {
  72         [GDT_ENTRY_KERNEL32_CS]         = GDT_ENTRY_INIT(0xc09b, 0, 0xfffff),
  73         [GDT_ENTRY_KERNEL_CS]           = GDT_ENTRY_INIT(0xa09b, 0, 0xfffff),
  74         [GDT_ENTRY_KERNEL_DS]           = GDT_ENTRY_INIT(0xc093, 0, 0xfffff),
  75 };
  76
  77 /*
  78  * Address needs to be set at runtime because it references the startup_gdt
  79  * while the kernel still uses a direct mapping.
  80  */
  81 static struct desc_ptr startup_gdt_descr = {
  82         .size = sizeof(startup_gdt),
  83         .address = 0,
  84 };
  85
  86 #define __head  __section(".head.text")
  87
  88 static void __head *fixup_pointer(void *ptr, unsigned long physaddr)
  89 {
  90         return ptr - (void *)_text + (void *)physaddr;
  91 }
  92
  93 static unsigned long __head *fixup_long(void *ptr, unsigned long physaddr)
  94 {
  95         return fixup_pointer(ptr, physaddr);
  96 }
  97
  98 #ifdef CONFIG_X86_5LEVEL
  99 static unsigned int __head *fixup_int(void *ptr, unsigned long physaddr)
 100 {
 101         return fixup_pointer(ptr, physaddr);
 102 }
 103
 104 static bool __head check_la57_support(unsigned long physaddr)
 105 {
 106         /*
 107          * 5-level paging is detected and enabled at kernel decompression
 108          * stage. Only check if it has been enabled there.
 109          */
 110         if (!(native_read_cr4() & X86_CR4_LA57))
 111                 return false;
 112
 113         *fixup_int(&__pgtable_l5_enabled, physaddr) = 1;
 114         *fixup_int(&pgdir_shift, physaddr) = 48;
 115         *fixup_int(&ptrs_per_p4d, physaddr) = 512;
 116         *fixup_long(&page_offset_base, physaddr) = __PAGE_OFFSET_BASE_L5;
 117         *fixup_long(&vmalloc_base, physaddr) = __VMALLOC_BASE_L5;
 118         *fixup_long(&vmemmap_base, physaddr) = __VMEMMAP_BASE_L5;
 119
 120         return true;
 121 }
 122 #else
 123 static bool __head check_la57_support(unsigned long physaddr)
 124 {
 125         return false;
 126 }
 127 #endif
 128
 129 static unsigned long sme_postprocess_startup(struct boot_params *bp, pmdval_t *pmd)
 130 {
 131         unsigned long vaddr, vaddr_end;
 132         int i;
 133
 134         /* Encrypt the kernel and related (if SME is active) */
 135         sme_encrypt_kernel(bp);
 136
 137         /*
 138          * Clear the memory encryption mask from the .bss..decrypted section.
 139          * The bss section will be memset to zero later in the initialization so
 140          * there is no need to zero it after changing the memory encryption
 141          * attribute.
 142          */
 143         if (sme_get_me_mask()) {
 144                 vaddr = (unsigned long)__start_bss_decrypted;
 145                 vaddr_end = (unsigned long)__end_bss_decrypted;
 146                 for (; vaddr < vaddr_end; vaddr += PMD_SIZE) {
 147                         i = pmd_index(vaddr);
 148                         pmd[i] -= sme_get_me_mask();
 149                 }
 150         }
 151
 152         /*
 153          * Return the SME encryption mask (if SME is active) to be used as a
 154          * modifier for the initial pgdir entry programmed into CR3.
 155          */
 156         return sme_get_me_mask();
 157 }
 158
 159 /* Code in __startup_64() can be relocated during execution, but the compiler
 160  * doesn't have to generate PC-relative relocations when accessing globals from
 161  * that function. Clang actually does not generate them, which leads to
 162  * boot-time crashes. To work around this problem, every global pointer must
 163  * be adjusted using fixup_pointer().
 164  */
 165 unsigned long __head __startup_64(unsigned long physaddr,
 166                                   struct boot_params *bp)
 167 {
 168         unsigned long load_delta, *p;
 169         unsigned long pgtable_flags;
 170         pgdval_t *pgd;
 171         p4dval_t *p4d;
 172         pudval_t *pud;
 173         pmdval_t *pmd, pmd_entry;
 174         pteval_t *mask_ptr;
 175         bool la57;
 176         int i;
 177         unsigned int *next_pgt_ptr;
 178
 179         la57 = check_la57_support(physaddr);
 180
 181         /* Is the address too large? */
 182         if (physaddr >> MAX_PHYSMEM_BITS)
 183                 for (;;);
 184
 185         /*
 186          * Compute the delta between the address I am compiled to run at
 187          * and the address I am actually running at.
 188          */
 189         load_delta = physaddr - (unsigned long)(_text - __START_KERNEL_map);
 190
 191         /* Is the address not 2M aligned? */
 192         if (load_delta & ~PMD_PAGE_MASK)
 193                 for (;;);
 194
 195         /* Activate Secure Memory Encryption (SME) if supported and enabled */
 196         sme_enable(bp);
 197
 198         /* Include the SME encryption mask in the fixup value */
 199         load_delta += sme_get_me_mask();
 200
 201         /* Fixup the physical addresses in the page table */
 202
 203         pgd = fixup_pointer(&early_top_pgt, physaddr);
 204         p = pgd + pgd_index(__START_KERNEL_map);
 205         if (la57)
 206                 *p = (unsigned long)level4_kernel_pgt;
 207         else
 208                 *p = (unsigned long)level3_kernel_pgt;
 209         *p += _PAGE_TABLE_NOENC - __START_KERNEL_map + load_delta;
 210
 211         if (la57) {
 212                 p4d = fixup_pointer(&level4_kernel_pgt, physaddr);
 213                 p4d[511] += load_delta;
 214         }
 215
 216         pud = fixup_pointer(&level3_kernel_pgt, physaddr);
 217         pud[510] += load_delta;
 218         pud[511] += load_delta;
 219
 220         pmd = fixup_pointer(level2_fixmap_pgt, physaddr);
 221         for (i = FIXMAP_PMD_TOP; i > FIXMAP_PMD_TOP - FIXMAP_PMD_NUM; i--)
 222                 pmd[i] += load_delta;
 223
 224         /*
 225          * Set up the identity mapping for the switchover.  These
 226          * entries should *NOT* have the global bit set!  This also
 227          * creates a bunch of nonsense entries but that is fine --
 228          * it avoids problems around wraparound.
 229          */
 230
 231         next_pgt_ptr = fixup_pointer(&next_early_pgt, physaddr);
 232         pud = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++], physaddr);
 233         pmd = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++], physaddr);
 234
 235         pgtable_flags = _KERNPG_TABLE_NOENC + sme_get_me_mask();
 236
 237         if (la57) {
 238                 p4d = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++],
 239                                     physaddr);
 240
 241                 i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD;
 242                 pgd[i + 0] = (pgdval_t)p4d + pgtable_flags;
 243                 pgd[i + 1] = (pgdval_t)p4d + pgtable_flags;
 244
 245                 i = physaddr >> P4D_SHIFT;
 246                 p4d[(i + 0) % PTRS_PER_P4D] = (pgdval_t)pud + pgtable_flags;
 247                 p4d[(i + 1) % PTRS_PER_P4D] = (pgdval_t)pud + pgtable_flags;
 248         } else {
 249                 i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD;
 250                 pgd[i + 0] = (pgdval_t)pud + pgtable_flags;
 251                 pgd[i + 1] = (pgdval_t)pud + pgtable_flags;
 252         }
 253
 254         i = physaddr >> PUD_SHIFT;
 255         pud[(i + 0) % PTRS_PER_PUD] = (pudval_t)pmd + pgtable_flags;
 256         pud[(i + 1) % PTRS_PER_PUD] = (pudval_t)pmd + pgtable_flags;
 257
 258         pmd_entry = __PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL;
 259         /* Filter out unsupported __PAGE_KERNEL_* bits: */
 260         mask_ptr = fixup_pointer(&__supported_pte_mask, physaddr);
 261         pmd_entry &= *mask_ptr;
 262         pmd_entry += sme_get_me_mask();
 263         pmd_entry +=  physaddr;
 264
 265         for (i = 0; i < DIV_ROUND_UP(_end - _text, PMD_SIZE); i++) {
 266                 int idx = i + (physaddr >> PMD_SHIFT);
 267
 268                 pmd[idx % PTRS_PER_PMD] = pmd_entry + i * PMD_SIZE;
 269         }
 270
 271         /*
 272          * Fixup the kernel text+data virtual addresses. Note that
 273          * we might write invalid pmds, when the kernel is relocated
 274          * cleanup_highmap() fixes this up along with the mappings
 275          * beyond _end.
 276          *
 277          * Only the region occupied by the kernel image has so far
 278          * been checked against the table of usable memory regions
 279          * provided by the firmware, so invalidate pages outside that
 280          * region. A page table entry that maps to a reserved area of
 281          * memory would allow processor speculation into that area,
 282          * and on some hardware (particularly the UV platform) even
 283          * speculative access to some reserved areas is caught as an
 284          * error, causing the BIOS to halt the system.
 285          */
 286
 287         pmd = fixup_pointer(level2_kernel_pgt, physaddr);
 288
 289         /* invalidate pages before the kernel image */
 290         for (i = 0; i < pmd_index((unsigned long)_text); i++)
 291                 pmd[i] &= ~_PAGE_PRESENT;
 292
 293         /* fixup pages that are part of the kernel image */
 294         for (; i <= pmd_index((unsigned long)_end); i++)
 295                 if (pmd[i] & _PAGE_PRESENT)
 296                         pmd[i] += load_delta;
 297
 298         /* invalidate pages after the kernel image */
 299         for (; i < PTRS_PER_PMD; i++)
 300                 pmd[i] &= ~_PAGE_PRESENT;
 301
 302         /*
 303          * Fixup phys_base - remove the memory encryption mask to obtain
 304          * the true physical address.
 305          */
 306         *fixup_long(&phys_base, physaddr) += load_delta - sme_get_me_mask();
 307
 308         return sme_postprocess_startup(bp, pmd);
 309 }
 310
 311 unsigned long __startup_secondary_64(void)
 312 {
 313         /*
 314          * Return the SME encryption mask (if SME is active) to be used as a
 315          * modifier for the initial pgdir entry programmed into CR3.
 316          */
 317         return sme_get_me_mask();
 318 }
 319
 320 /* Wipe all early page tables except for the kernel symbol map */
 321 static void __init reset_early_page_tables(void)
 322 {
 323         memset(early_top_pgt, 0, sizeof(pgd_t)*(PTRS_PER_PGD-1));
 324         next_early_pgt = 0;
 325         write_cr3(__sme_pa_nodebug(early_top_pgt));
 326 }
 327
 328 /* Create a new PMD entry */
 329 bool __init __early_make_pgtable(unsigned long address, pmdval_t pmd)
 330 {
 331         unsigned long physaddr = address - __PAGE_OFFSET;
 332         pgdval_t pgd, *pgd_p;
 333         p4dval_t p4d, *p4d_p;
 334         pudval_t pud, *pud_p;
 335         pmdval_t *pmd_p;
 336
 337         /* Invalid address or early pgt is done ?  */
 338         if (physaddr >= MAXMEM || read_cr3_pa() != __pa_nodebug(early_top_pgt))
 339                 return false;
 340
 341 again:
 342         pgd_p = &early_top_pgt[pgd_index(address)].pgd;
 343         pgd = *pgd_p;
 344
 345         /*
 346          * The use of __START_KERNEL_map rather than __PAGE_OFFSET here is
 347          * critical -- __PAGE_OFFSET would point us back into the dynamic
 348          * range and we might end up looping forever...
 349          */
 350         if (!pgtable_l5_enabled())
 351                 p4d_p = pgd_p;
 352         else if (pgd)
 353                 p4d_p = (p4dval_t *)((pgd & 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                 p4d_p = (p4dval_t *)early_dynamic_pgts[next_early_pgt++];
 361                 memset(p4d_p, 0, sizeof(*p4d_p) * PTRS_PER_P4D);
 362                 *pgd_p = (pgdval_t)p4d_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
 363         }
 364         p4d_p += p4d_index(address);
 365         p4d = *p4d_p;
 366
 367         if (p4d)
 368                 pud_p = (pudval_t *)((p4d & 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                 pud_p = (pudval_t *)early_dynamic_pgts[next_early_pgt++];
 376                 memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
 377                 *p4d_p = (p4dval_t)pud_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
 378         }
 379         pud_p += pud_index(address);
 380         pud = *pud_p;
 381
 382         if (pud)
 383                 pmd_p = (pmdval_t *)((pud & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
 384         else {
 385                 if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) {
 386                         reset_early_page_tables();
 387                         goto again;
 388                 }
 389
 390                 pmd_p = (pmdval_t *)early_dynamic_pgts[next_early_pgt++];
 391                 memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD);
 392                 *pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
 393         }
 394         pmd_p[pmd_index(address)] = pmd;
 395
 396         return true;
 397 }
 398
 399 static bool __init early_make_pgtable(unsigned long address)
 400 {
 401         unsigned long physaddr = address - __PAGE_OFFSET;
 402         pmdval_t pmd;
 403
 404         pmd = (physaddr & PMD_MASK) + early_pmd_flags;
 405
 406         return __early_make_pgtable(address, pmd);
 407 }
 408
 409 void __init do_early_exception(struct pt_regs *regs, int trapnr)
 410 {
 411         if (trapnr == X86_TRAP_PF &&
 412             early_make_pgtable(native_read_cr2()))
 413                 return;
 414
 415         if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT) &&
 416             trapnr == X86_TRAP_VC && handle_vc_boot_ghcb(regs))
 417                 return;
 418
 419         early_fixup_exception(regs, trapnr);
 420 }
 421
 422 /* Don't add a printk in there. printk relies on the PDA which is not initialized
 423    yet. */
 424 static void __init clear_bss(void)
 425 {
 426         memset(__bss_start, 0,
 427                (unsigned long) __bss_stop - (unsigned long) __bss_start);
 428 }
 429
 430 static unsigned long get_cmd_line_ptr(void)
 431 {
 432         unsigned long cmd_line_ptr = boot_params.hdr.cmd_line_ptr;
 433
 434         cmd_line_ptr |= (u64)boot_params.ext_cmd_line_ptr << 32;
 435
 436         return cmd_line_ptr;
 437 }
 438
 439 static void __init copy_bootdata(char *real_mode_data)
 440 {
 441         char * command_line;
 442         unsigned long cmd_line_ptr;
 443
 444         /*
 445          * If SME is active, this will create decrypted mappings of the
 446          * boot data in advance of the copy operations.
 447          */
 448         sme_map_bootdata(real_mode_data);
 449
 450         memcpy(&boot_params, real_mode_data, sizeof(boot_params));
 451         sanitize_boot_params(&boot_params);
 452         cmd_line_ptr = get_cmd_line_ptr();
 453         if (cmd_line_ptr) {
 454                 command_line = __va(cmd_line_ptr);
 455                 memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
 456         }
 457
 458         /*
 459          * The old boot data is no longer needed and won't be reserved,
 460          * freeing up that memory for use by the system. If SME is active,
 461          * we need to remove the mappings that were created so that the
 462          * memory doesn't remain mapped as decrypted.
 463          */
 464         sme_unmap_bootdata(real_mode_data);
 465 }
 466
 467 asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data)
 468 {
 469         /*
 470          * Build-time sanity checks on the kernel image and module
 471          * area mappings. (these are purely build-time and produce no code)
 472          */
 473         BUILD_BUG_ON(MODULES_VADDR < __START_KERNEL_map);
 474         BUILD_BUG_ON(MODULES_VADDR - __START_KERNEL_map < KERNEL_IMAGE_SIZE);
 475         BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE);
 476         BUILD_BUG_ON((__START_KERNEL_map & ~PMD_MASK) != 0);
 477         BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0);
 478         BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL));
 479         MAYBE_BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
 480                                 (__START_KERNEL & PGDIR_MASK)));
 481         BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END);
 482
 483         cr4_init_shadow();
 484
 485         /* Kill off the identity-map trampoline */
 486         reset_early_page_tables();
 487
 488         clear_bss();
 489
 490         /*
 491          * This needs to happen *before* kasan_early_init() because latter maps stuff
 492          * into that page.
 493          */
 494         clear_page(init_top_pgt);
 495
 496         /*
 497          * SME support may update early_pmd_flags to include the memory
 498          * encryption mask, so it needs to be called before anything
 499          * that may generate a page fault.
 500          */
 501         sme_early_init();
 502
 503         kasan_early_init();
 504
 505         /*
 506          * Flush global TLB entries which could be left over from the trampoline page
 507          * table.
 508          *
 509          * This needs to happen *after* kasan_early_init() as KASAN-enabled .configs
 510          * instrument native_write_cr4() so KASAN must be initialized for that
 511          * instrumentation to work.
 512          */
 513         __native_tlb_flush_global(this_cpu_read(cpu_tlbstate.cr4));
 514
 515         idt_setup_early_handler();
 516
 517         copy_bootdata(__va(real_mode_data));
 518
 519         /*
 520          * Load microcode early on BSP.
 521          */
 522         load_ucode_bsp();
 523
 524         /* set init_top_pgt kernel high mapping*/
 525         init_top_pgt[511] = early_top_pgt[511];
 526
 527         x86_64_start_reservations(real_mode_data);
 528 }
 529
 530 void __init x86_64_start_reservations(char *real_mode_data)
 531 {
 532         /* version is always not zero if it is copied */
 533         if (!boot_params.hdr.version)
 534                 copy_bootdata(__va(real_mode_data));
 535
 536         x86_early_init_platform_quirks();
 537
 538         switch (boot_params.hdr.hardware_subarch) {
 539         case X86_SUBARCH_INTEL_MID:
 540                 x86_intel_mid_early_setup();
 541                 break;
 542         default:
 543                 break;
 544         }
 545
 546         start_kernel();
 547 }
 548
 549 /*
 550  * Data structures and code used for IDT setup in head_64.S. The bringup-IDT is
 551  * used until the idt_table takes over. On the boot CPU this happens in
 552  * x86_64_start_kernel(), on secondary CPUs in start_secondary(). In both cases
 553  * this happens in the functions called from head_64.S.
 554  *
 555  * The idt_table can't be used that early because all the code modifying it is
 556  * in idt.c and can be instrumented by tracing or KASAN, which both don't work
 557  * during early CPU bringup. Also the idt_table has the runtime vectors
 558  * configured which require certain CPU state to be setup already (like TSS),
 559  * which also hasn't happened yet in early CPU bringup.
 560  */
 561 static gate_desc bringup_idt_table[NUM_EXCEPTION_VECTORS] __page_aligned_data;
 562
 563 static struct desc_ptr bringup_idt_descr = {
 564         .size           = (NUM_EXCEPTION_VECTORS * sizeof(gate_desc)) - 1,
 565         .address        = 0, /* Set at runtime */
 566 };
 567
 568 static void set_bringup_idt_handler(gate_desc *idt, int n, void *handler)
 569 {
 570 #ifdef CONFIG_AMD_MEM_ENCRYPT
 571         struct idt_data data;
 572         gate_desc desc;
 573
 574         init_idt_data(&data, n, handler);
 575         idt_init_desc(&desc, &data);
 576         native_write_idt_entry(idt, n, &desc);
 577 #endif
 578 }
 579
 580 /* This runs while still in the direct mapping */
 581 static void startup_64_load_idt(unsigned long physbase)
 582 {
 583         struct desc_ptr *desc = fixup_pointer(&bringup_idt_descr, physbase);
 584         gate_desc *idt = fixup_pointer(bringup_idt_table, physbase);
 585
 586
 587         if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {
 588                 void *handler;
 589
 590                 /* VMM Communication Exception */
 591                 handler = fixup_pointer(vc_no_ghcb, physbase);
 592                 set_bringup_idt_handler(idt, X86_TRAP_VC, handler);
 593         }
 594
 595         desc->address = (unsigned long)idt;
 596         native_load_idt(desc);
 597 }
 598
 599 /* This is used when running on kernel addresses */
 600 void early_setup_idt(void)
 601 {
 602         /* VMM Communication Exception */
 603         if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT))
 604                 set_bringup_idt_handler(bringup_idt_table, X86_TRAP_VC, vc_boot_ghcb);
 605
 606         bringup_idt_descr.address = (unsigned long)bringup_idt_table;
 607         native_load_idt(&bringup_idt_descr);
 608 }
 609
 610 /*
 611  * Setup boot CPU state needed before kernel switches to virtual addresses.
 612  */
 613 void __head startup_64_setup_env(unsigned long physbase)
 614 {
 615         /* Load GDT */
 616         startup_gdt_descr.address = (unsigned long)fixup_pointer(startup_gdt, physbase);
 617         native_load_gdt(&startup_gdt_descr);
 618
 619         /* New GDT is live - reload data segment registers */
 620         asm volatile("movl %%eax, %%ds\n"
 621                      "movl %%eax, %%ss\n"
 622                      "movl %%eax, %%es\n" : : "a"(__KERNEL_DS) : "memory");
 623
 624         startup_64_load_idt(physbase);
 625 }