1 /* 2 * Core of Xen paravirt_ops implementation. 3 * 4 * This file contains the xen_paravirt_ops structure itself, and the 5 * implementations for: 6 * - privileged instructions 7 * - interrupt flags 8 * - segment operations 9 * - booting and setup 10 * 11 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007 12 */ 13 14 #include <linux/cpu.h> 15 #include <linux/kernel.h> 16 #include <linux/init.h> 17 #include <linux/smp.h> 18 #include <linux/preempt.h> 19 #include <linux/hardirq.h> 20 #include <linux/percpu.h> 21 #include <linux/delay.h> 22 #include <linux/start_kernel.h> 23 #include <linux/sched.h> 24 #include <linux/kprobes.h> 25 #include <linux/bootmem.h> 26 #include <linux/module.h> 27 #include <linux/mm.h> 28 #include <linux/page-flags.h> 29 #include <linux/highmem.h> 30 #include <linux/console.h> 31 #include <linux/pci.h> 32 #include <linux/gfp.h> 33 #include <linux/memblock.h> 34 35 #include <xen/xen.h> 36 #include <xen/interface/xen.h> 37 #include <xen/interface/version.h> 38 #include <xen/interface/physdev.h> 39 #include <xen/interface/vcpu.h> 40 #include <xen/interface/memory.h> 41 #include <xen/features.h> 42 #include <xen/page.h> 43 #include <xen/hvm.h> 44 #include <xen/hvc-console.h> 45 46 #include <asm/paravirt.h> 47 #include <asm/apic.h> 48 #include <asm/page.h> 49 #include <asm/xen/pci.h> 50 #include <asm/xen/hypercall.h> 51 #include <asm/xen/hypervisor.h> 52 #include <asm/fixmap.h> 53 #include <asm/processor.h> 54 #include <asm/proto.h> 55 #include <asm/msr-index.h> 56 #include <asm/traps.h> 57 #include <asm/setup.h> 58 #include <asm/desc.h> 59 #include <asm/pgalloc.h> 60 #include <asm/pgtable.h> 61 #include <asm/tlbflush.h> 62 #include <asm/reboot.h> 63 #include <asm/stackprotector.h> 64 #include <asm/hypervisor.h> 65 66 #include "xen-ops.h" 67 #include "mmu.h" 68 #include "multicalls.h" 69 70 EXPORT_SYMBOL_GPL(hypercall_page); 71 72 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu); 73 DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info); 74 75 enum xen_domain_type xen_domain_type = XEN_NATIVE; 76 EXPORT_SYMBOL_GPL(xen_domain_type); 77 78 unsigned long *machine_to_phys_mapping = (void *)MACH2PHYS_VIRT_START; 79 EXPORT_SYMBOL(machine_to_phys_mapping); 80 unsigned long machine_to_phys_nr; 81 EXPORT_SYMBOL(machine_to_phys_nr); 82 83 struct start_info *xen_start_info; 84 EXPORT_SYMBOL_GPL(xen_start_info); 85 86 struct shared_info xen_dummy_shared_info; 87 88 void *xen_initial_gdt; 89 90 RESERVE_BRK(shared_info_page_brk, PAGE_SIZE); 91 __read_mostly int xen_have_vector_callback; 92 EXPORT_SYMBOL_GPL(xen_have_vector_callback); 93 94 /* 95 * Point at some empty memory to start with. We map the real shared_info 96 * page as soon as fixmap is up and running. 97 */ 98 struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info; 99 100 /* 101 * Flag to determine whether vcpu info placement is available on all 102 * VCPUs. We assume it is to start with, and then set it to zero on 103 * the first failure. This is because it can succeed on some VCPUs 104 * and not others, since it can involve hypervisor memory allocation, 105 * or because the guest failed to guarantee all the appropriate 106 * constraints on all VCPUs (ie buffer can't cross a page boundary). 107 * 108 * Note that any particular CPU may be using a placed vcpu structure, 109 * but we can only optimise if the all are. 110 * 111 * 0: not available, 1: available 112 */ 113 static int have_vcpu_info_placement = 1; 114 115 static void clamp_max_cpus(void) 116 { 117 #ifdef CONFIG_SMP 118 if (setup_max_cpus > MAX_VIRT_CPUS) 119 setup_max_cpus = MAX_VIRT_CPUS; 120 #endif 121 } 122 123 static void xen_vcpu_setup(int cpu) 124 { 125 struct vcpu_register_vcpu_info info; 126 int err; 127 struct vcpu_info *vcpup; 128 129 BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info); 130 131 if (cpu < MAX_VIRT_CPUS) 132 per_cpu(xen_vcpu,cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu]; 133 134 if (!have_vcpu_info_placement) { 135 if (cpu >= MAX_VIRT_CPUS) 136 clamp_max_cpus(); 137 return; 138 } 139 140 vcpup = &per_cpu(xen_vcpu_info, cpu); 141 info.mfn = arbitrary_virt_to_mfn(vcpup); 142 info.offset = offset_in_page(vcpup); 143 144 /* Check to see if the hypervisor will put the vcpu_info 145 structure where we want it, which allows direct access via 146 a percpu-variable. */ 147 err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info); 148 149 if (err) { 150 printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err); 151 have_vcpu_info_placement = 0; 152 clamp_max_cpus(); 153 } else { 154 /* This cpu is using the registered vcpu info, even if 155 later ones fail to. */ 156 per_cpu(xen_vcpu, cpu) = vcpup; 157 } 158 } 159 160 /* 161 * On restore, set the vcpu placement up again. 162 * If it fails, then we're in a bad state, since 163 * we can't back out from using it... 164 */ 165 void xen_vcpu_restore(void) 166 { 167 int cpu; 168 169 for_each_online_cpu(cpu) { 170 bool other_cpu = (cpu != smp_processor_id()); 171 172 if (other_cpu && 173 HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL)) 174 BUG(); 175 176 xen_setup_runstate_info(cpu); 177 178 if (have_vcpu_info_placement) 179 xen_vcpu_setup(cpu); 180 181 if (other_cpu && 182 HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL)) 183 BUG(); 184 } 185 } 186 187 static void __init xen_banner(void) 188 { 189 unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL); 190 struct xen_extraversion extra; 191 HYPERVISOR_xen_version(XENVER_extraversion, &extra); 192 193 printk(KERN_INFO "Booting paravirtualized kernel on %s\n", 194 pv_info.name); 195 printk(KERN_INFO "Xen version: %d.%d%s%s\n", 196 version >> 16, version & 0xffff, extra.extraversion, 197 xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : ""); 198 } 199 200 static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0; 201 static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0; 202 203 static void xen_cpuid(unsigned int *ax, unsigned int *bx, 204 unsigned int *cx, unsigned int *dx) 205 { 206 unsigned maskebx = ~0; 207 unsigned maskecx = ~0; 208 unsigned maskedx = ~0; 209 210 /* 211 * Mask out inconvenient features, to try and disable as many 212 * unsupported kernel subsystems as possible. 213 */ 214 switch (*ax) { 215 case 1: 216 maskecx = cpuid_leaf1_ecx_mask; 217 maskedx = cpuid_leaf1_edx_mask; 218 break; 219 220 case 0xb: 221 /* Suppress extended topology stuff */ 222 maskebx = 0; 223 break; 224 } 225 226 asm(XEN_EMULATE_PREFIX "cpuid" 227 : "=a" (*ax), 228 "=b" (*bx), 229 "=c" (*cx), 230 "=d" (*dx) 231 : "0" (*ax), "2" (*cx)); 232 233 *bx &= maskebx; 234 *cx &= maskecx; 235 *dx &= maskedx; 236 } 237 238 static void __init xen_init_cpuid_mask(void) 239 { 240 unsigned int ax, bx, cx, dx; 241 unsigned int xsave_mask; 242 243 cpuid_leaf1_edx_mask = 244 ~((1 << X86_FEATURE_MCE) | /* disable MCE */ 245 (1 << X86_FEATURE_MCA) | /* disable MCA */ 246 (1 << X86_FEATURE_MTRR) | /* disable MTRR */ 247 (1 << X86_FEATURE_ACC)); /* thermal monitoring */ 248 249 if (!xen_initial_domain()) 250 cpuid_leaf1_edx_mask &= 251 ~((1 << X86_FEATURE_APIC) | /* disable local APIC */ 252 (1 << X86_FEATURE_ACPI)); /* disable ACPI */ 253 ax = 1; 254 cx = 0; 255 xen_cpuid(&ax, &bx, &cx, &dx); 256 257 xsave_mask = 258 (1 << (X86_FEATURE_XSAVE % 32)) | 259 (1 << (X86_FEATURE_OSXSAVE % 32)); 260 261 /* Xen will set CR4.OSXSAVE if supported and not disabled by force */ 262 if ((cx & xsave_mask) != xsave_mask) 263 cpuid_leaf1_ecx_mask &= ~xsave_mask; /* disable XSAVE & OSXSAVE */ 264 } 265 266 static void xen_set_debugreg(int reg, unsigned long val) 267 { 268 HYPERVISOR_set_debugreg(reg, val); 269 } 270 271 static unsigned long xen_get_debugreg(int reg) 272 { 273 return HYPERVISOR_get_debugreg(reg); 274 } 275 276 static void xen_end_context_switch(struct task_struct *next) 277 { 278 xen_mc_flush(); 279 paravirt_end_context_switch(next); 280 } 281 282 static unsigned long xen_store_tr(void) 283 { 284 return 0; 285 } 286 287 /* 288 * Set the page permissions for a particular virtual address. If the 289 * address is a vmalloc mapping (or other non-linear mapping), then 290 * find the linear mapping of the page and also set its protections to 291 * match. 292 */ 293 static void set_aliased_prot(void *v, pgprot_t prot) 294 { 295 int level; 296 pte_t *ptep; 297 pte_t pte; 298 unsigned long pfn; 299 struct page *page; 300 301 ptep = lookup_address((unsigned long)v, &level); 302 BUG_ON(ptep == NULL); 303 304 pfn = pte_pfn(*ptep); 305 page = pfn_to_page(pfn); 306 307 pte = pfn_pte(pfn, prot); 308 309 if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0)) 310 BUG(); 311 312 if (!PageHighMem(page)) { 313 void *av = __va(PFN_PHYS(pfn)); 314 315 if (av != v) 316 if (HYPERVISOR_update_va_mapping((unsigned long)av, pte, 0)) 317 BUG(); 318 } else 319 kmap_flush_unused(); 320 } 321 322 static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries) 323 { 324 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE; 325 int i; 326 327 for(i = 0; i < entries; i += entries_per_page) 328 set_aliased_prot(ldt + i, PAGE_KERNEL_RO); 329 } 330 331 static void xen_free_ldt(struct desc_struct *ldt, unsigned entries) 332 { 333 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE; 334 int i; 335 336 for(i = 0; i < entries; i += entries_per_page) 337 set_aliased_prot(ldt + i, PAGE_KERNEL); 338 } 339 340 static void xen_set_ldt(const void *addr, unsigned entries) 341 { 342 struct mmuext_op *op; 343 struct multicall_space mcs = xen_mc_entry(sizeof(*op)); 344 345 trace_xen_cpu_set_ldt(addr, entries); 346 347 op = mcs.args; 348 op->cmd = MMUEXT_SET_LDT; 349 op->arg1.linear_addr = (unsigned long)addr; 350 op->arg2.nr_ents = entries; 351 352 MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF); 353 354 xen_mc_issue(PARAVIRT_LAZY_CPU); 355 } 356 357 static void xen_load_gdt(const struct desc_ptr *dtr) 358 { 359 unsigned long va = dtr->address; 360 unsigned int size = dtr->size + 1; 361 unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE; 362 unsigned long frames[pages]; 363 int f; 364 365 /* 366 * A GDT can be up to 64k in size, which corresponds to 8192 367 * 8-byte entries, or 16 4k pages.. 368 */ 369 370 BUG_ON(size > 65536); 371 BUG_ON(va & ~PAGE_MASK); 372 373 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) { 374 int level; 375 pte_t *ptep; 376 unsigned long pfn, mfn; 377 void *virt; 378 379 /* 380 * The GDT is per-cpu and is in the percpu data area. 381 * That can be virtually mapped, so we need to do a 382 * page-walk to get the underlying MFN for the 383 * hypercall. The page can also be in the kernel's 384 * linear range, so we need to RO that mapping too. 385 */ 386 ptep = lookup_address(va, &level); 387 BUG_ON(ptep == NULL); 388 389 pfn = pte_pfn(*ptep); 390 mfn = pfn_to_mfn(pfn); 391 virt = __va(PFN_PHYS(pfn)); 392 393 frames[f] = mfn; 394 395 make_lowmem_page_readonly((void *)va); 396 make_lowmem_page_readonly(virt); 397 } 398 399 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct))) 400 BUG(); 401 } 402 403 /* 404 * load_gdt for early boot, when the gdt is only mapped once 405 */ 406 static void __init xen_load_gdt_boot(const struct desc_ptr *dtr) 407 { 408 unsigned long va = dtr->address; 409 unsigned int size = dtr->size + 1; 410 unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE; 411 unsigned long frames[pages]; 412 int f; 413 414 /* 415 * A GDT can be up to 64k in size, which corresponds to 8192 416 * 8-byte entries, or 16 4k pages.. 417 */ 418 419 BUG_ON(size > 65536); 420 BUG_ON(va & ~PAGE_MASK); 421 422 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) { 423 pte_t pte; 424 unsigned long pfn, mfn; 425 426 pfn = virt_to_pfn(va); 427 mfn = pfn_to_mfn(pfn); 428 429 pte = pfn_pte(pfn, PAGE_KERNEL_RO); 430 431 if (HYPERVISOR_update_va_mapping((unsigned long)va, pte, 0)) 432 BUG(); 433 434 frames[f] = mfn; 435 } 436 437 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct))) 438 BUG(); 439 } 440 441 static void load_TLS_descriptor(struct thread_struct *t, 442 unsigned int cpu, unsigned int i) 443 { 444 struct desc_struct *gdt = get_cpu_gdt_table(cpu); 445 xmaddr_t maddr = arbitrary_virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]); 446 struct multicall_space mc = __xen_mc_entry(0); 447 448 MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]); 449 } 450 451 static void xen_load_tls(struct thread_struct *t, unsigned int cpu) 452 { 453 /* 454 * XXX sleazy hack: If we're being called in a lazy-cpu zone 455 * and lazy gs handling is enabled, it means we're in a 456 * context switch, and %gs has just been saved. This means we 457 * can zero it out to prevent faults on exit from the 458 * hypervisor if the next process has no %gs. Either way, it 459 * has been saved, and the new value will get loaded properly. 460 * This will go away as soon as Xen has been modified to not 461 * save/restore %gs for normal hypercalls. 462 * 463 * On x86_64, this hack is not used for %gs, because gs points 464 * to KERNEL_GS_BASE (and uses it for PDA references), so we 465 * must not zero %gs on x86_64 466 * 467 * For x86_64, we need to zero %fs, otherwise we may get an 468 * exception between the new %fs descriptor being loaded and 469 * %fs being effectively cleared at __switch_to(). 470 */ 471 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) { 472 #ifdef CONFIG_X86_32 473 lazy_load_gs(0); 474 #else 475 loadsegment(fs, 0); 476 #endif 477 } 478 479 xen_mc_batch(); 480 481 load_TLS_descriptor(t, cpu, 0); 482 load_TLS_descriptor(t, cpu, 1); 483 load_TLS_descriptor(t, cpu, 2); 484 485 xen_mc_issue(PARAVIRT_LAZY_CPU); 486 } 487 488 #ifdef CONFIG_X86_64 489 static void xen_load_gs_index(unsigned int idx) 490 { 491 if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL, idx)) 492 BUG(); 493 } 494 #endif 495 496 static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum, 497 const void *ptr) 498 { 499 xmaddr_t mach_lp = arbitrary_virt_to_machine(&dt[entrynum]); 500 u64 entry = *(u64 *)ptr; 501 502 trace_xen_cpu_write_ldt_entry(dt, entrynum, entry); 503 504 preempt_disable(); 505 506 xen_mc_flush(); 507 if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry)) 508 BUG(); 509 510 preempt_enable(); 511 } 512 513 static int cvt_gate_to_trap(int vector, const gate_desc *val, 514 struct trap_info *info) 515 { 516 unsigned long addr; 517 518 if (val->type != GATE_TRAP && val->type != GATE_INTERRUPT) 519 return 0; 520 521 info->vector = vector; 522 523 addr = gate_offset(*val); 524 #ifdef CONFIG_X86_64 525 /* 526 * Look for known traps using IST, and substitute them 527 * appropriately. The debugger ones are the only ones we care 528 * about. Xen will handle faults like double_fault and 529 * machine_check, so we should never see them. Warn if 530 * there's an unexpected IST-using fault handler. 531 */ 532 if (addr == (unsigned long)debug) 533 addr = (unsigned long)xen_debug; 534 else if (addr == (unsigned long)int3) 535 addr = (unsigned long)xen_int3; 536 else if (addr == (unsigned long)stack_segment) 537 addr = (unsigned long)xen_stack_segment; 538 else if (addr == (unsigned long)double_fault || 539 addr == (unsigned long)nmi) { 540 /* Don't need to handle these */ 541 return 0; 542 #ifdef CONFIG_X86_MCE 543 } else if (addr == (unsigned long)machine_check) { 544 return 0; 545 #endif 546 } else { 547 /* Some other trap using IST? */ 548 if (WARN_ON(val->ist != 0)) 549 return 0; 550 } 551 #endif /* CONFIG_X86_64 */ 552 info->address = addr; 553 554 info->cs = gate_segment(*val); 555 info->flags = val->dpl; 556 /* interrupt gates clear IF */ 557 if (val->type == GATE_INTERRUPT) 558 info->flags |= 1 << 2; 559 560 return 1; 561 } 562 563 /* Locations of each CPU's IDT */ 564 static DEFINE_PER_CPU(struct desc_ptr, idt_desc); 565 566 /* Set an IDT entry. If the entry is part of the current IDT, then 567 also update Xen. */ 568 static void xen_write_idt_entry(gate_desc *dt, int entrynum, const gate_desc *g) 569 { 570 unsigned long p = (unsigned long)&dt[entrynum]; 571 unsigned long start, end; 572 573 trace_xen_cpu_write_idt_entry(dt, entrynum, g); 574 575 preempt_disable(); 576 577 start = __this_cpu_read(idt_desc.address); 578 end = start + __this_cpu_read(idt_desc.size) + 1; 579 580 xen_mc_flush(); 581 582 native_write_idt_entry(dt, entrynum, g); 583 584 if (p >= start && (p + 8) <= end) { 585 struct trap_info info[2]; 586 587 info[1].address = 0; 588 589 if (cvt_gate_to_trap(entrynum, g, &info[0])) 590 if (HYPERVISOR_set_trap_table(info)) 591 BUG(); 592 } 593 594 preempt_enable(); 595 } 596 597 static void xen_convert_trap_info(const struct desc_ptr *desc, 598 struct trap_info *traps) 599 { 600 unsigned in, out, count; 601 602 count = (desc->size+1) / sizeof(gate_desc); 603 BUG_ON(count > 256); 604 605 for (in = out = 0; in < count; in++) { 606 gate_desc *entry = (gate_desc*)(desc->address) + in; 607 608 if (cvt_gate_to_trap(in, entry, &traps[out])) 609 out++; 610 } 611 traps[out].address = 0; 612 } 613 614 void xen_copy_trap_info(struct trap_info *traps) 615 { 616 const struct desc_ptr *desc = &__get_cpu_var(idt_desc); 617 618 xen_convert_trap_info(desc, traps); 619 } 620 621 /* Load a new IDT into Xen. In principle this can be per-CPU, so we 622 hold a spinlock to protect the static traps[] array (static because 623 it avoids allocation, and saves stack space). */ 624 static void xen_load_idt(const struct desc_ptr *desc) 625 { 626 static DEFINE_SPINLOCK(lock); 627 static struct trap_info traps[257]; 628 629 trace_xen_cpu_load_idt(desc); 630 631 spin_lock(&lock); 632 633 __get_cpu_var(idt_desc) = *desc; 634 635 xen_convert_trap_info(desc, traps); 636 637 xen_mc_flush(); 638 if (HYPERVISOR_set_trap_table(traps)) 639 BUG(); 640 641 spin_unlock(&lock); 642 } 643 644 /* Write a GDT descriptor entry. Ignore LDT descriptors, since 645 they're handled differently. */ 646 static void xen_write_gdt_entry(struct desc_struct *dt, int entry, 647 const void *desc, int type) 648 { 649 trace_xen_cpu_write_gdt_entry(dt, entry, desc, type); 650 651 preempt_disable(); 652 653 switch (type) { 654 case DESC_LDT: 655 case DESC_TSS: 656 /* ignore */ 657 break; 658 659 default: { 660 xmaddr_t maddr = arbitrary_virt_to_machine(&dt[entry]); 661 662 xen_mc_flush(); 663 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc)) 664 BUG(); 665 } 666 667 } 668 669 preempt_enable(); 670 } 671 672 /* 673 * Version of write_gdt_entry for use at early boot-time needed to 674 * update an entry as simply as possible. 675 */ 676 static void __init xen_write_gdt_entry_boot(struct desc_struct *dt, int entry, 677 const void *desc, int type) 678 { 679 trace_xen_cpu_write_gdt_entry(dt, entry, desc, type); 680 681 switch (type) { 682 case DESC_LDT: 683 case DESC_TSS: 684 /* ignore */ 685 break; 686 687 default: { 688 xmaddr_t maddr = virt_to_machine(&dt[entry]); 689 690 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc)) 691 dt[entry] = *(struct desc_struct *)desc; 692 } 693 694 } 695 } 696 697 static void xen_load_sp0(struct tss_struct *tss, 698 struct thread_struct *thread) 699 { 700 struct multicall_space mcs; 701 702 mcs = xen_mc_entry(0); 703 MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->sp0); 704 xen_mc_issue(PARAVIRT_LAZY_CPU); 705 } 706 707 static void xen_set_iopl_mask(unsigned mask) 708 { 709 struct physdev_set_iopl set_iopl; 710 711 /* Force the change at ring 0. */ 712 set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3; 713 HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl); 714 } 715 716 static void xen_io_delay(void) 717 { 718 } 719 720 #ifdef CONFIG_X86_LOCAL_APIC 721 static u32 xen_apic_read(u32 reg) 722 { 723 return 0; 724 } 725 726 static void xen_apic_write(u32 reg, u32 val) 727 { 728 /* Warn to see if there's any stray references */ 729 WARN_ON(1); 730 } 731 732 static u64 xen_apic_icr_read(void) 733 { 734 return 0; 735 } 736 737 static void xen_apic_icr_write(u32 low, u32 id) 738 { 739 /* Warn to see if there's any stray references */ 740 WARN_ON(1); 741 } 742 743 static void xen_apic_wait_icr_idle(void) 744 { 745 return; 746 } 747 748 static u32 xen_safe_apic_wait_icr_idle(void) 749 { 750 return 0; 751 } 752 753 static void set_xen_basic_apic_ops(void) 754 { 755 apic->read = xen_apic_read; 756 apic->write = xen_apic_write; 757 apic->icr_read = xen_apic_icr_read; 758 apic->icr_write = xen_apic_icr_write; 759 apic->wait_icr_idle = xen_apic_wait_icr_idle; 760 apic->safe_wait_icr_idle = xen_safe_apic_wait_icr_idle; 761 } 762 763 #endif 764 765 static void xen_clts(void) 766 { 767 struct multicall_space mcs; 768 769 mcs = xen_mc_entry(0); 770 771 MULTI_fpu_taskswitch(mcs.mc, 0); 772 773 xen_mc_issue(PARAVIRT_LAZY_CPU); 774 } 775 776 static DEFINE_PER_CPU(unsigned long, xen_cr0_value); 777 778 static unsigned long xen_read_cr0(void) 779 { 780 unsigned long cr0 = percpu_read(xen_cr0_value); 781 782 if (unlikely(cr0 == 0)) { 783 cr0 = native_read_cr0(); 784 percpu_write(xen_cr0_value, cr0); 785 } 786 787 return cr0; 788 } 789 790 static void xen_write_cr0(unsigned long cr0) 791 { 792 struct multicall_space mcs; 793 794 percpu_write(xen_cr0_value, cr0); 795 796 /* Only pay attention to cr0.TS; everything else is 797 ignored. */ 798 mcs = xen_mc_entry(0); 799 800 MULTI_fpu_taskswitch(mcs.mc, (cr0 & X86_CR0_TS) != 0); 801 802 xen_mc_issue(PARAVIRT_LAZY_CPU); 803 } 804 805 static void xen_write_cr4(unsigned long cr4) 806 { 807 cr4 &= ~X86_CR4_PGE; 808 cr4 &= ~X86_CR4_PSE; 809 810 native_write_cr4(cr4); 811 } 812 813 static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high) 814 { 815 int ret; 816 817 ret = 0; 818 819 switch (msr) { 820 #ifdef CONFIG_X86_64 821 unsigned which; 822 u64 base; 823 824 case MSR_FS_BASE: which = SEGBASE_FS; goto set; 825 case MSR_KERNEL_GS_BASE: which = SEGBASE_GS_USER; goto set; 826 case MSR_GS_BASE: which = SEGBASE_GS_KERNEL; goto set; 827 828 set: 829 base = ((u64)high << 32) | low; 830 if (HYPERVISOR_set_segment_base(which, base) != 0) 831 ret = -EIO; 832 break; 833 #endif 834 835 case MSR_STAR: 836 case MSR_CSTAR: 837 case MSR_LSTAR: 838 case MSR_SYSCALL_MASK: 839 case MSR_IA32_SYSENTER_CS: 840 case MSR_IA32_SYSENTER_ESP: 841 case MSR_IA32_SYSENTER_EIP: 842 /* Fast syscall setup is all done in hypercalls, so 843 these are all ignored. Stub them out here to stop 844 Xen console noise. */ 845 break; 846 847 case MSR_IA32_CR_PAT: 848 if (smp_processor_id() == 0) 849 xen_set_pat(((u64)high << 32) | low); 850 break; 851 852 default: 853 ret = native_write_msr_safe(msr, low, high); 854 } 855 856 return ret; 857 } 858 859 void xen_setup_shared_info(void) 860 { 861 if (!xen_feature(XENFEAT_auto_translated_physmap)) { 862 set_fixmap(FIX_PARAVIRT_BOOTMAP, 863 xen_start_info->shared_info); 864 865 HYPERVISOR_shared_info = 866 (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP); 867 } else 868 HYPERVISOR_shared_info = 869 (struct shared_info *)__va(xen_start_info->shared_info); 870 871 #ifndef CONFIG_SMP 872 /* In UP this is as good a place as any to set up shared info */ 873 xen_setup_vcpu_info_placement(); 874 #endif 875 876 xen_setup_mfn_list_list(); 877 } 878 879 /* This is called once we have the cpu_possible_map */ 880 void xen_setup_vcpu_info_placement(void) 881 { 882 int cpu; 883 884 for_each_possible_cpu(cpu) 885 xen_vcpu_setup(cpu); 886 887 /* xen_vcpu_setup managed to place the vcpu_info within the 888 percpu area for all cpus, so make use of it */ 889 if (have_vcpu_info_placement) { 890 pv_irq_ops.save_fl = __PV_IS_CALLEE_SAVE(xen_save_fl_direct); 891 pv_irq_ops.restore_fl = __PV_IS_CALLEE_SAVE(xen_restore_fl_direct); 892 pv_irq_ops.irq_disable = __PV_IS_CALLEE_SAVE(xen_irq_disable_direct); 893 pv_irq_ops.irq_enable = __PV_IS_CALLEE_SAVE(xen_irq_enable_direct); 894 pv_mmu_ops.read_cr2 = xen_read_cr2_direct; 895 } 896 } 897 898 static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf, 899 unsigned long addr, unsigned len) 900 { 901 char *start, *end, *reloc; 902 unsigned ret; 903 904 start = end = reloc = NULL; 905 906 #define SITE(op, x) \ 907 case PARAVIRT_PATCH(op.x): \ 908 if (have_vcpu_info_placement) { \ 909 start = (char *)xen_##x##_direct; \ 910 end = xen_##x##_direct_end; \ 911 reloc = xen_##x##_direct_reloc; \ 912 } \ 913 goto patch_site 914 915 switch (type) { 916 SITE(pv_irq_ops, irq_enable); 917 SITE(pv_irq_ops, irq_disable); 918 SITE(pv_irq_ops, save_fl); 919 SITE(pv_irq_ops, restore_fl); 920 #undef SITE 921 922 patch_site: 923 if (start == NULL || (end-start) > len) 924 goto default_patch; 925 926 ret = paravirt_patch_insns(insnbuf, len, start, end); 927 928 /* Note: because reloc is assigned from something that 929 appears to be an array, gcc assumes it's non-null, 930 but doesn't know its relationship with start and 931 end. */ 932 if (reloc > start && reloc < end) { 933 int reloc_off = reloc - start; 934 long *relocp = (long *)(insnbuf + reloc_off); 935 long delta = start - (char *)addr; 936 937 *relocp += delta; 938 } 939 break; 940 941 default_patch: 942 default: 943 ret = paravirt_patch_default(type, clobbers, insnbuf, 944 addr, len); 945 break; 946 } 947 948 return ret; 949 } 950 951 static const struct pv_info xen_info __initconst = { 952 .paravirt_enabled = 1, 953 .shared_kernel_pmd = 0, 954 955 #ifdef CONFIG_X86_64 956 .extra_user_64bit_cs = FLAT_USER_CS64, 957 #endif 958 959 .name = "Xen", 960 }; 961 962 static const struct pv_init_ops xen_init_ops __initconst = { 963 .patch = xen_patch, 964 }; 965 966 static const struct pv_cpu_ops xen_cpu_ops __initconst = { 967 .cpuid = xen_cpuid, 968 969 .set_debugreg = xen_set_debugreg, 970 .get_debugreg = xen_get_debugreg, 971 972 .clts = xen_clts, 973 974 .read_cr0 = xen_read_cr0, 975 .write_cr0 = xen_write_cr0, 976 977 .read_cr4 = native_read_cr4, 978 .read_cr4_safe = native_read_cr4_safe, 979 .write_cr4 = xen_write_cr4, 980 981 .wbinvd = native_wbinvd, 982 983 .read_msr = native_read_msr_safe, 984 .write_msr = xen_write_msr_safe, 985 .read_tsc = native_read_tsc, 986 .read_pmc = native_read_pmc, 987 988 .iret = xen_iret, 989 .irq_enable_sysexit = xen_sysexit, 990 #ifdef CONFIG_X86_64 991 .usergs_sysret32 = xen_sysret32, 992 .usergs_sysret64 = xen_sysret64, 993 #endif 994 995 .load_tr_desc = paravirt_nop, 996 .set_ldt = xen_set_ldt, 997 .load_gdt = xen_load_gdt, 998 .load_idt = xen_load_idt, 999 .load_tls = xen_load_tls, 1000 #ifdef CONFIG_X86_64 1001 .load_gs_index = xen_load_gs_index, 1002 #endif 1003 1004 .alloc_ldt = xen_alloc_ldt, 1005 .free_ldt = xen_free_ldt, 1006 1007 .store_gdt = native_store_gdt, 1008 .store_idt = native_store_idt, 1009 .store_tr = xen_store_tr, 1010 1011 .write_ldt_entry = xen_write_ldt_entry, 1012 .write_gdt_entry = xen_write_gdt_entry, 1013 .write_idt_entry = xen_write_idt_entry, 1014 .load_sp0 = xen_load_sp0, 1015 1016 .set_iopl_mask = xen_set_iopl_mask, 1017 .io_delay = xen_io_delay, 1018 1019 /* Xen takes care of %gs when switching to usermode for us */ 1020 .swapgs = paravirt_nop, 1021 1022 .start_context_switch = paravirt_start_context_switch, 1023 .end_context_switch = xen_end_context_switch, 1024 }; 1025 1026 static const struct pv_apic_ops xen_apic_ops __initconst = { 1027 #ifdef CONFIG_X86_LOCAL_APIC 1028 .startup_ipi_hook = paravirt_nop, 1029 #endif 1030 }; 1031 1032 static void xen_reboot(int reason) 1033 { 1034 struct sched_shutdown r = { .reason = reason }; 1035 1036 if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r)) 1037 BUG(); 1038 } 1039 1040 static void xen_restart(char *msg) 1041 { 1042 xen_reboot(SHUTDOWN_reboot); 1043 } 1044 1045 static void xen_emergency_restart(void) 1046 { 1047 xen_reboot(SHUTDOWN_reboot); 1048 } 1049 1050 static void xen_machine_halt(void) 1051 { 1052 xen_reboot(SHUTDOWN_poweroff); 1053 } 1054 1055 static void xen_machine_power_off(void) 1056 { 1057 if (pm_power_off) 1058 pm_power_off(); 1059 xen_reboot(SHUTDOWN_poweroff); 1060 } 1061 1062 static void xen_crash_shutdown(struct pt_regs *regs) 1063 { 1064 xen_reboot(SHUTDOWN_crash); 1065 } 1066 1067 static int 1068 xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr) 1069 { 1070 xen_reboot(SHUTDOWN_crash); 1071 return NOTIFY_DONE; 1072 } 1073 1074 static struct notifier_block xen_panic_block = { 1075 .notifier_call= xen_panic_event, 1076 }; 1077 1078 int xen_panic_handler_init(void) 1079 { 1080 atomic_notifier_chain_register(&panic_notifier_list, &xen_panic_block); 1081 return 0; 1082 } 1083 1084 static const struct machine_ops xen_machine_ops __initconst = { 1085 .restart = xen_restart, 1086 .halt = xen_machine_halt, 1087 .power_off = xen_machine_power_off, 1088 .shutdown = xen_machine_halt, 1089 .crash_shutdown = xen_crash_shutdown, 1090 .emergency_restart = xen_emergency_restart, 1091 }; 1092 1093 /* 1094 * Set up the GDT and segment registers for -fstack-protector. Until 1095 * we do this, we have to be careful not to call any stack-protected 1096 * function, which is most of the kernel. 1097 */ 1098 static void __init xen_setup_stackprotector(void) 1099 { 1100 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry_boot; 1101 pv_cpu_ops.load_gdt = xen_load_gdt_boot; 1102 1103 setup_stack_canary_segment(0); 1104 switch_to_new_gdt(0); 1105 1106 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry; 1107 pv_cpu_ops.load_gdt = xen_load_gdt; 1108 } 1109 1110 /* First C function to be called on Xen boot */ 1111 asmlinkage void __init xen_start_kernel(void) 1112 { 1113 struct physdev_set_iopl set_iopl; 1114 int rc; 1115 pgd_t *pgd; 1116 1117 if (!xen_start_info) 1118 return; 1119 1120 xen_domain_type = XEN_PV_DOMAIN; 1121 1122 xen_setup_machphys_mapping(); 1123 1124 /* Install Xen paravirt ops */ 1125 pv_info = xen_info; 1126 pv_init_ops = xen_init_ops; 1127 pv_cpu_ops = xen_cpu_ops; 1128 pv_apic_ops = xen_apic_ops; 1129 1130 x86_init.resources.memory_setup = xen_memory_setup; 1131 x86_init.oem.arch_setup = xen_arch_setup; 1132 x86_init.oem.banner = xen_banner; 1133 1134 xen_init_time_ops(); 1135 1136 /* 1137 * Set up some pagetable state before starting to set any ptes. 1138 */ 1139 1140 xen_init_mmu_ops(); 1141 1142 /* Prevent unwanted bits from being set in PTEs. */ 1143 __supported_pte_mask &= ~_PAGE_GLOBAL; 1144 if (!xen_initial_domain()) 1145 __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD); 1146 1147 __supported_pte_mask |= _PAGE_IOMAP; 1148 1149 /* 1150 * Prevent page tables from being allocated in highmem, even 1151 * if CONFIG_HIGHPTE is enabled. 1152 */ 1153 __userpte_alloc_gfp &= ~__GFP_HIGHMEM; 1154 1155 /* Work out if we support NX */ 1156 x86_configure_nx(); 1157 1158 xen_setup_features(); 1159 1160 /* Get mfn list */ 1161 if (!xen_feature(XENFEAT_auto_translated_physmap)) 1162 xen_build_dynamic_phys_to_machine(); 1163 1164 /* 1165 * Set up kernel GDT and segment registers, mainly so that 1166 * -fstack-protector code can be executed. 1167 */ 1168 xen_setup_stackprotector(); 1169 1170 xen_init_irq_ops(); 1171 xen_init_cpuid_mask(); 1172 1173 #ifdef CONFIG_X86_LOCAL_APIC 1174 /* 1175 * set up the basic apic ops. 1176 */ 1177 set_xen_basic_apic_ops(); 1178 #endif 1179 1180 if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) { 1181 pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start; 1182 pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit; 1183 } 1184 1185 machine_ops = xen_machine_ops; 1186 1187 /* 1188 * The only reliable way to retain the initial address of the 1189 * percpu gdt_page is to remember it here, so we can go and 1190 * mark it RW later, when the initial percpu area is freed. 1191 */ 1192 xen_initial_gdt = &per_cpu(gdt_page, 0); 1193 1194 xen_smp_init(); 1195 1196 #ifdef CONFIG_ACPI_NUMA 1197 /* 1198 * The pages we from Xen are not related to machine pages, so 1199 * any NUMA information the kernel tries to get from ACPI will 1200 * be meaningless. Prevent it from trying. 1201 */ 1202 acpi_numa = -1; 1203 #endif 1204 1205 pgd = (pgd_t *)xen_start_info->pt_base; 1206 1207 if (!xen_initial_domain()) 1208 __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD); 1209 1210 __supported_pte_mask |= _PAGE_IOMAP; 1211 /* Don't do the full vcpu_info placement stuff until we have a 1212 possible map and a non-dummy shared_info. */ 1213 per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0]; 1214 1215 local_irq_disable(); 1216 early_boot_irqs_disabled = true; 1217 1218 memblock_init(); 1219 1220 xen_raw_console_write("mapping kernel into physical memory\n"); 1221 pgd = xen_setup_kernel_pagetable(pgd, xen_start_info->nr_pages); 1222 xen_ident_map_ISA(); 1223 1224 /* Allocate and initialize top and mid mfn levels for p2m structure */ 1225 xen_build_mfn_list_list(); 1226 1227 /* keep using Xen gdt for now; no urgent need to change it */ 1228 1229 #ifdef CONFIG_X86_32 1230 pv_info.kernel_rpl = 1; 1231 if (xen_feature(XENFEAT_supervisor_mode_kernel)) 1232 pv_info.kernel_rpl = 0; 1233 #else 1234 pv_info.kernel_rpl = 0; 1235 #endif 1236 /* set the limit of our address space */ 1237 xen_reserve_top(); 1238 1239 /* We used to do this in xen_arch_setup, but that is too late on AMD 1240 * were early_cpu_init (run before ->arch_setup()) calls early_amd_init 1241 * which pokes 0xcf8 port. 1242 */ 1243 set_iopl.iopl = 1; 1244 rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl); 1245 if (rc != 0) 1246 xen_raw_printk("physdev_op failed %d\n", rc); 1247 1248 #ifdef CONFIG_X86_32 1249 /* set up basic CPUID stuff */ 1250 cpu_detect(&new_cpu_data); 1251 new_cpu_data.hard_math = 1; 1252 new_cpu_data.wp_works_ok = 1; 1253 new_cpu_data.x86_capability[0] = cpuid_edx(1); 1254 #endif 1255 1256 /* Poke various useful things into boot_params */ 1257 boot_params.hdr.type_of_loader = (9 << 4) | 0; 1258 boot_params.hdr.ramdisk_image = xen_start_info->mod_start 1259 ? __pa(xen_start_info->mod_start) : 0; 1260 boot_params.hdr.ramdisk_size = xen_start_info->mod_len; 1261 boot_params.hdr.cmd_line_ptr = __pa(xen_start_info->cmd_line); 1262 1263 if (!xen_initial_domain()) { 1264 add_preferred_console("xenboot", 0, NULL); 1265 add_preferred_console("tty", 0, NULL); 1266 add_preferred_console("hvc", 0, NULL); 1267 if (pci_xen) 1268 x86_init.pci.arch_init = pci_xen_init; 1269 } else { 1270 const struct dom0_vga_console_info *info = 1271 (void *)((char *)xen_start_info + 1272 xen_start_info->console.dom0.info_off); 1273 1274 xen_init_vga(info, xen_start_info->console.dom0.info_size); 1275 xen_start_info->console.domU.mfn = 0; 1276 xen_start_info->console.domU.evtchn = 0; 1277 1278 /* Make sure ACS will be enabled */ 1279 pci_request_acs(); 1280 } 1281 1282 1283 xen_raw_console_write("about to get started...\n"); 1284 1285 xen_setup_runstate_info(0); 1286 1287 /* Start the world */ 1288 #ifdef CONFIG_X86_32 1289 i386_start_kernel(); 1290 #else 1291 x86_64_start_reservations((char *)__pa_symbol(&boot_params)); 1292 #endif 1293 } 1294 1295 static int init_hvm_pv_info(int *major, int *minor) 1296 { 1297 uint32_t eax, ebx, ecx, edx, pages, msr, base; 1298 u64 pfn; 1299 1300 base = xen_cpuid_base(); 1301 cpuid(base + 1, &eax, &ebx, &ecx, &edx); 1302 1303 *major = eax >> 16; 1304 *minor = eax & 0xffff; 1305 printk(KERN_INFO "Xen version %d.%d.\n", *major, *minor); 1306 1307 cpuid(base + 2, &pages, &msr, &ecx, &edx); 1308 1309 pfn = __pa(hypercall_page); 1310 wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32)); 1311 1312 xen_setup_features(); 1313 1314 pv_info.name = "Xen HVM"; 1315 1316 xen_domain_type = XEN_HVM_DOMAIN; 1317 1318 return 0; 1319 } 1320 1321 void __ref xen_hvm_init_shared_info(void) 1322 { 1323 int cpu; 1324 struct xen_add_to_physmap xatp; 1325 static struct shared_info *shared_info_page = 0; 1326 1327 if (!shared_info_page) 1328 shared_info_page = (struct shared_info *) 1329 extend_brk(PAGE_SIZE, PAGE_SIZE); 1330 xatp.domid = DOMID_SELF; 1331 xatp.idx = 0; 1332 xatp.space = XENMAPSPACE_shared_info; 1333 xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT; 1334 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp)) 1335 BUG(); 1336 1337 HYPERVISOR_shared_info = (struct shared_info *)shared_info_page; 1338 1339 /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info 1340 * page, we use it in the event channel upcall and in some pvclock 1341 * related functions. We don't need the vcpu_info placement 1342 * optimizations because we don't use any pv_mmu or pv_irq op on 1343 * HVM. 1344 * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is 1345 * online but xen_hvm_init_shared_info is run at resume time too and 1346 * in that case multiple vcpus might be online. */ 1347 for_each_online_cpu(cpu) { 1348 per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu]; 1349 } 1350 } 1351 1352 #ifdef CONFIG_XEN_PVHVM 1353 static int __cpuinit xen_hvm_cpu_notify(struct notifier_block *self, 1354 unsigned long action, void *hcpu) 1355 { 1356 int cpu = (long)hcpu; 1357 switch (action) { 1358 case CPU_UP_PREPARE: 1359 per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu]; 1360 if (xen_have_vector_callback) 1361 xen_init_lock_cpu(cpu); 1362 break; 1363 default: 1364 break; 1365 } 1366 return NOTIFY_OK; 1367 } 1368 1369 static struct notifier_block xen_hvm_cpu_notifier __cpuinitdata = { 1370 .notifier_call = xen_hvm_cpu_notify, 1371 }; 1372 1373 static void __init xen_hvm_guest_init(void) 1374 { 1375 int r; 1376 int major, minor; 1377 1378 r = init_hvm_pv_info(&major, &minor); 1379 if (r < 0) 1380 return; 1381 1382 xen_hvm_init_shared_info(); 1383 1384 if (xen_feature(XENFEAT_hvm_callback_vector)) 1385 xen_have_vector_callback = 1; 1386 xen_hvm_smp_init(); 1387 register_cpu_notifier(&xen_hvm_cpu_notifier); 1388 xen_unplug_emulated_devices(); 1389 have_vcpu_info_placement = 0; 1390 x86_init.irqs.intr_init = xen_init_IRQ; 1391 xen_hvm_init_time_ops(); 1392 xen_hvm_init_mmu_ops(); 1393 } 1394 1395 static bool __init xen_hvm_platform(void) 1396 { 1397 if (xen_pv_domain()) 1398 return false; 1399 1400 if (!xen_cpuid_base()) 1401 return false; 1402 1403 return true; 1404 } 1405 1406 bool xen_hvm_need_lapic(void) 1407 { 1408 if (xen_pv_domain()) 1409 return false; 1410 if (!xen_hvm_domain()) 1411 return false; 1412 if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback) 1413 return false; 1414 return true; 1415 } 1416 EXPORT_SYMBOL_GPL(xen_hvm_need_lapic); 1417 1418 const struct hypervisor_x86 x86_hyper_xen_hvm __refconst = { 1419 .name = "Xen HVM", 1420 .detect = xen_hvm_platform, 1421 .init_platform = xen_hvm_guest_init, 1422 }; 1423 EXPORT_SYMBOL(x86_hyper_xen_hvm); 1424 #endif 1425