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 #include <linux/syscore_ops.h> 35 36 #include <xen/xen.h> 37 #include <xen/interface/xen.h> 38 #include <xen/interface/version.h> 39 #include <xen/interface/physdev.h> 40 #include <xen/interface/vcpu.h> 41 #include <xen/interface/memory.h> 42 #include <xen/interface/xen-mca.h> 43 #include <xen/features.h> 44 #include <xen/page.h> 45 #include <xen/hvm.h> 46 #include <xen/hvc-console.h> 47 #include <xen/acpi.h> 48 49 #include <asm/paravirt.h> 50 #include <asm/apic.h> 51 #include <asm/page.h> 52 #include <asm/xen/pci.h> 53 #include <asm/xen/hypercall.h> 54 #include <asm/xen/hypervisor.h> 55 #include <asm/fixmap.h> 56 #include <asm/processor.h> 57 #include <asm/proto.h> 58 #include <asm/msr-index.h> 59 #include <asm/traps.h> 60 #include <asm/setup.h> 61 #include <asm/desc.h> 62 #include <asm/pgalloc.h> 63 #include <asm/pgtable.h> 64 #include <asm/tlbflush.h> 65 #include <asm/reboot.h> 66 #include <asm/stackprotector.h> 67 #include <asm/hypervisor.h> 68 #include <asm/mwait.h> 69 #include <asm/pci_x86.h> 70 71 #ifdef CONFIG_ACPI 72 #include <linux/acpi.h> 73 #include <asm/acpi.h> 74 #include <acpi/pdc_intel.h> 75 #include <acpi/processor.h> 76 #include <xen/interface/platform.h> 77 #endif 78 79 #include "xen-ops.h" 80 #include "mmu.h" 81 #include "smp.h" 82 #include "multicalls.h" 83 84 EXPORT_SYMBOL_GPL(hypercall_page); 85 86 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu); 87 DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info); 88 89 enum xen_domain_type xen_domain_type = XEN_NATIVE; 90 EXPORT_SYMBOL_GPL(xen_domain_type); 91 92 unsigned long *machine_to_phys_mapping = (void *)MACH2PHYS_VIRT_START; 93 EXPORT_SYMBOL(machine_to_phys_mapping); 94 unsigned long machine_to_phys_nr; 95 EXPORT_SYMBOL(machine_to_phys_nr); 96 97 struct start_info *xen_start_info; 98 EXPORT_SYMBOL_GPL(xen_start_info); 99 100 struct shared_info xen_dummy_shared_info; 101 102 void *xen_initial_gdt; 103 104 RESERVE_BRK(shared_info_page_brk, PAGE_SIZE); 105 __read_mostly int xen_have_vector_callback; 106 EXPORT_SYMBOL_GPL(xen_have_vector_callback); 107 108 /* 109 * Point at some empty memory to start with. We map the real shared_info 110 * page as soon as fixmap is up and running. 111 */ 112 struct shared_info *HYPERVISOR_shared_info = &xen_dummy_shared_info; 113 114 /* 115 * Flag to determine whether vcpu info placement is available on all 116 * VCPUs. We assume it is to start with, and then set it to zero on 117 * the first failure. This is because it can succeed on some VCPUs 118 * and not others, since it can involve hypervisor memory allocation, 119 * or because the guest failed to guarantee all the appropriate 120 * constraints on all VCPUs (ie buffer can't cross a page boundary). 121 * 122 * Note that any particular CPU may be using a placed vcpu structure, 123 * but we can only optimise if the all are. 124 * 125 * 0: not available, 1: available 126 */ 127 static int have_vcpu_info_placement = 1; 128 129 struct tls_descs { 130 struct desc_struct desc[3]; 131 }; 132 133 /* 134 * Updating the 3 TLS descriptors in the GDT on every task switch is 135 * surprisingly expensive so we avoid updating them if they haven't 136 * changed. Since Xen writes different descriptors than the one 137 * passed in the update_descriptor hypercall we keep shadow copies to 138 * compare against. 139 */ 140 static DEFINE_PER_CPU(struct tls_descs, shadow_tls_desc); 141 142 static void clamp_max_cpus(void) 143 { 144 #ifdef CONFIG_SMP 145 if (setup_max_cpus > MAX_VIRT_CPUS) 146 setup_max_cpus = MAX_VIRT_CPUS; 147 #endif 148 } 149 150 static void xen_vcpu_setup(int cpu) 151 { 152 struct vcpu_register_vcpu_info info; 153 int err; 154 struct vcpu_info *vcpup; 155 156 BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info); 157 158 if (cpu < MAX_VIRT_CPUS) 159 per_cpu(xen_vcpu,cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu]; 160 161 if (!have_vcpu_info_placement) { 162 if (cpu >= MAX_VIRT_CPUS) 163 clamp_max_cpus(); 164 return; 165 } 166 167 vcpup = &per_cpu(xen_vcpu_info, cpu); 168 info.mfn = arbitrary_virt_to_mfn(vcpup); 169 info.offset = offset_in_page(vcpup); 170 171 /* Check to see if the hypervisor will put the vcpu_info 172 structure where we want it, which allows direct access via 173 a percpu-variable. */ 174 err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info); 175 176 if (err) { 177 printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err); 178 have_vcpu_info_placement = 0; 179 clamp_max_cpus(); 180 } else { 181 /* This cpu is using the registered vcpu info, even if 182 later ones fail to. */ 183 per_cpu(xen_vcpu, cpu) = vcpup; 184 } 185 } 186 187 /* 188 * On restore, set the vcpu placement up again. 189 * If it fails, then we're in a bad state, since 190 * we can't back out from using it... 191 */ 192 void xen_vcpu_restore(void) 193 { 194 int cpu; 195 196 for_each_online_cpu(cpu) { 197 bool other_cpu = (cpu != smp_processor_id()); 198 199 if (other_cpu && 200 HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL)) 201 BUG(); 202 203 xen_setup_runstate_info(cpu); 204 205 if (have_vcpu_info_placement) 206 xen_vcpu_setup(cpu); 207 208 if (other_cpu && 209 HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL)) 210 BUG(); 211 } 212 } 213 214 static void __init xen_banner(void) 215 { 216 unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL); 217 struct xen_extraversion extra; 218 HYPERVISOR_xen_version(XENVER_extraversion, &extra); 219 220 printk(KERN_INFO "Booting paravirtualized kernel on %s\n", 221 pv_info.name); 222 printk(KERN_INFO "Xen version: %d.%d%s%s\n", 223 version >> 16, version & 0xffff, extra.extraversion, 224 xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : ""); 225 } 226 227 #define CPUID_THERM_POWER_LEAF 6 228 #define APERFMPERF_PRESENT 0 229 230 static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0; 231 static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0; 232 233 static __read_mostly unsigned int cpuid_leaf1_ecx_set_mask; 234 static __read_mostly unsigned int cpuid_leaf5_ecx_val; 235 static __read_mostly unsigned int cpuid_leaf5_edx_val; 236 237 static void xen_cpuid(unsigned int *ax, unsigned int *bx, 238 unsigned int *cx, unsigned int *dx) 239 { 240 unsigned maskebx = ~0; 241 unsigned maskecx = ~0; 242 unsigned maskedx = ~0; 243 unsigned setecx = 0; 244 /* 245 * Mask out inconvenient features, to try and disable as many 246 * unsupported kernel subsystems as possible. 247 */ 248 switch (*ax) { 249 case 1: 250 maskecx = cpuid_leaf1_ecx_mask; 251 setecx = cpuid_leaf1_ecx_set_mask; 252 maskedx = cpuid_leaf1_edx_mask; 253 break; 254 255 case CPUID_MWAIT_LEAF: 256 /* Synthesize the values.. */ 257 *ax = 0; 258 *bx = 0; 259 *cx = cpuid_leaf5_ecx_val; 260 *dx = cpuid_leaf5_edx_val; 261 return; 262 263 case CPUID_THERM_POWER_LEAF: 264 /* Disabling APERFMPERF for kernel usage */ 265 maskecx = ~(1 << APERFMPERF_PRESENT); 266 break; 267 268 case 0xb: 269 /* Suppress extended topology stuff */ 270 maskebx = 0; 271 break; 272 } 273 274 asm(XEN_EMULATE_PREFIX "cpuid" 275 : "=a" (*ax), 276 "=b" (*bx), 277 "=c" (*cx), 278 "=d" (*dx) 279 : "0" (*ax), "2" (*cx)); 280 281 *bx &= maskebx; 282 *cx &= maskecx; 283 *cx |= setecx; 284 *dx &= maskedx; 285 286 } 287 288 static bool __init xen_check_mwait(void) 289 { 290 #if defined(CONFIG_ACPI) && !defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR) && \ 291 !defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR_MODULE) 292 struct xen_platform_op op = { 293 .cmd = XENPF_set_processor_pminfo, 294 .u.set_pminfo.id = -1, 295 .u.set_pminfo.type = XEN_PM_PDC, 296 }; 297 uint32_t buf[3]; 298 unsigned int ax, bx, cx, dx; 299 unsigned int mwait_mask; 300 301 /* We need to determine whether it is OK to expose the MWAIT 302 * capability to the kernel to harvest deeper than C3 states from ACPI 303 * _CST using the processor_harvest_xen.c module. For this to work, we 304 * need to gather the MWAIT_LEAF values (which the cstate.c code 305 * checks against). The hypervisor won't expose the MWAIT flag because 306 * it would break backwards compatibility; so we will find out directly 307 * from the hardware and hypercall. 308 */ 309 if (!xen_initial_domain()) 310 return false; 311 312 ax = 1; 313 cx = 0; 314 315 native_cpuid(&ax, &bx, &cx, &dx); 316 317 mwait_mask = (1 << (X86_FEATURE_EST % 32)) | 318 (1 << (X86_FEATURE_MWAIT % 32)); 319 320 if ((cx & mwait_mask) != mwait_mask) 321 return false; 322 323 /* We need to emulate the MWAIT_LEAF and for that we need both 324 * ecx and edx. The hypercall provides only partial information. 325 */ 326 327 ax = CPUID_MWAIT_LEAF; 328 bx = 0; 329 cx = 0; 330 dx = 0; 331 332 native_cpuid(&ax, &bx, &cx, &dx); 333 334 /* Ask the Hypervisor whether to clear ACPI_PDC_C_C2C3_FFH. If so, 335 * don't expose MWAIT_LEAF and let ACPI pick the IOPORT version of C3. 336 */ 337 buf[0] = ACPI_PDC_REVISION_ID; 338 buf[1] = 1; 339 buf[2] = (ACPI_PDC_C_CAPABILITY_SMP | ACPI_PDC_EST_CAPABILITY_SWSMP); 340 341 set_xen_guest_handle(op.u.set_pminfo.pdc, buf); 342 343 if ((HYPERVISOR_dom0_op(&op) == 0) && 344 (buf[2] & (ACPI_PDC_C_C1_FFH | ACPI_PDC_C_C2C3_FFH))) { 345 cpuid_leaf5_ecx_val = cx; 346 cpuid_leaf5_edx_val = dx; 347 } 348 return true; 349 #else 350 return false; 351 #endif 352 } 353 static void __init xen_init_cpuid_mask(void) 354 { 355 unsigned int ax, bx, cx, dx; 356 unsigned int xsave_mask; 357 358 cpuid_leaf1_edx_mask = 359 ~((1 << X86_FEATURE_MTRR) | /* disable MTRR */ 360 (1 << X86_FEATURE_ACC)); /* thermal monitoring */ 361 362 if (!xen_initial_domain()) 363 cpuid_leaf1_edx_mask &= 364 ~((1 << X86_FEATURE_APIC) | /* disable local APIC */ 365 (1 << X86_FEATURE_ACPI)); /* disable ACPI */ 366 ax = 1; 367 cx = 0; 368 xen_cpuid(&ax, &bx, &cx, &dx); 369 370 xsave_mask = 371 (1 << (X86_FEATURE_XSAVE % 32)) | 372 (1 << (X86_FEATURE_OSXSAVE % 32)); 373 374 /* Xen will set CR4.OSXSAVE if supported and not disabled by force */ 375 if ((cx & xsave_mask) != xsave_mask) 376 cpuid_leaf1_ecx_mask &= ~xsave_mask; /* disable XSAVE & OSXSAVE */ 377 if (xen_check_mwait()) 378 cpuid_leaf1_ecx_set_mask = (1 << (X86_FEATURE_MWAIT % 32)); 379 } 380 381 static void xen_set_debugreg(int reg, unsigned long val) 382 { 383 HYPERVISOR_set_debugreg(reg, val); 384 } 385 386 static unsigned long xen_get_debugreg(int reg) 387 { 388 return HYPERVISOR_get_debugreg(reg); 389 } 390 391 static void xen_end_context_switch(struct task_struct *next) 392 { 393 xen_mc_flush(); 394 paravirt_end_context_switch(next); 395 } 396 397 static unsigned long xen_store_tr(void) 398 { 399 return 0; 400 } 401 402 /* 403 * Set the page permissions for a particular virtual address. If the 404 * address is a vmalloc mapping (or other non-linear mapping), then 405 * find the linear mapping of the page and also set its protections to 406 * match. 407 */ 408 static void set_aliased_prot(void *v, pgprot_t prot) 409 { 410 int level; 411 pte_t *ptep; 412 pte_t pte; 413 unsigned long pfn; 414 struct page *page; 415 416 ptep = lookup_address((unsigned long)v, &level); 417 BUG_ON(ptep == NULL); 418 419 pfn = pte_pfn(*ptep); 420 page = pfn_to_page(pfn); 421 422 pte = pfn_pte(pfn, prot); 423 424 if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0)) 425 BUG(); 426 427 if (!PageHighMem(page)) { 428 void *av = __va(PFN_PHYS(pfn)); 429 430 if (av != v) 431 if (HYPERVISOR_update_va_mapping((unsigned long)av, pte, 0)) 432 BUG(); 433 } else 434 kmap_flush_unused(); 435 } 436 437 static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries) 438 { 439 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE; 440 int i; 441 442 for(i = 0; i < entries; i += entries_per_page) 443 set_aliased_prot(ldt + i, PAGE_KERNEL_RO); 444 } 445 446 static void xen_free_ldt(struct desc_struct *ldt, unsigned entries) 447 { 448 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE; 449 int i; 450 451 for(i = 0; i < entries; i += entries_per_page) 452 set_aliased_prot(ldt + i, PAGE_KERNEL); 453 } 454 455 static void xen_set_ldt(const void *addr, unsigned entries) 456 { 457 struct mmuext_op *op; 458 struct multicall_space mcs = xen_mc_entry(sizeof(*op)); 459 460 trace_xen_cpu_set_ldt(addr, entries); 461 462 op = mcs.args; 463 op->cmd = MMUEXT_SET_LDT; 464 op->arg1.linear_addr = (unsigned long)addr; 465 op->arg2.nr_ents = entries; 466 467 MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF); 468 469 xen_mc_issue(PARAVIRT_LAZY_CPU); 470 } 471 472 static void xen_load_gdt(const struct desc_ptr *dtr) 473 { 474 unsigned long va = dtr->address; 475 unsigned int size = dtr->size + 1; 476 unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE; 477 unsigned long frames[pages]; 478 int f; 479 480 /* 481 * A GDT can be up to 64k in size, which corresponds to 8192 482 * 8-byte entries, or 16 4k pages.. 483 */ 484 485 BUG_ON(size > 65536); 486 BUG_ON(va & ~PAGE_MASK); 487 488 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) { 489 int level; 490 pte_t *ptep; 491 unsigned long pfn, mfn; 492 void *virt; 493 494 /* 495 * The GDT is per-cpu and is in the percpu data area. 496 * That can be virtually mapped, so we need to do a 497 * page-walk to get the underlying MFN for the 498 * hypercall. The page can also be in the kernel's 499 * linear range, so we need to RO that mapping too. 500 */ 501 ptep = lookup_address(va, &level); 502 BUG_ON(ptep == NULL); 503 504 pfn = pte_pfn(*ptep); 505 mfn = pfn_to_mfn(pfn); 506 virt = __va(PFN_PHYS(pfn)); 507 508 frames[f] = mfn; 509 510 make_lowmem_page_readonly((void *)va); 511 make_lowmem_page_readonly(virt); 512 } 513 514 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct))) 515 BUG(); 516 } 517 518 /* 519 * load_gdt for early boot, when the gdt is only mapped once 520 */ 521 static void __init xen_load_gdt_boot(const struct desc_ptr *dtr) 522 { 523 unsigned long va = dtr->address; 524 unsigned int size = dtr->size + 1; 525 unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE; 526 unsigned long frames[pages]; 527 int f; 528 529 /* 530 * A GDT can be up to 64k in size, which corresponds to 8192 531 * 8-byte entries, or 16 4k pages.. 532 */ 533 534 BUG_ON(size > 65536); 535 BUG_ON(va & ~PAGE_MASK); 536 537 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) { 538 pte_t pte; 539 unsigned long pfn, mfn; 540 541 pfn = virt_to_pfn(va); 542 mfn = pfn_to_mfn(pfn); 543 544 pte = pfn_pte(pfn, PAGE_KERNEL_RO); 545 546 if (HYPERVISOR_update_va_mapping((unsigned long)va, pte, 0)) 547 BUG(); 548 549 frames[f] = mfn; 550 } 551 552 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct))) 553 BUG(); 554 } 555 556 static inline bool desc_equal(const struct desc_struct *d1, 557 const struct desc_struct *d2) 558 { 559 return d1->a == d2->a && d1->b == d2->b; 560 } 561 562 static void load_TLS_descriptor(struct thread_struct *t, 563 unsigned int cpu, unsigned int i) 564 { 565 struct desc_struct *shadow = &per_cpu(shadow_tls_desc, cpu).desc[i]; 566 struct desc_struct *gdt; 567 xmaddr_t maddr; 568 struct multicall_space mc; 569 570 if (desc_equal(shadow, &t->tls_array[i])) 571 return; 572 573 *shadow = t->tls_array[i]; 574 575 gdt = get_cpu_gdt_table(cpu); 576 maddr = arbitrary_virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]); 577 mc = __xen_mc_entry(0); 578 579 MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]); 580 } 581 582 static void xen_load_tls(struct thread_struct *t, unsigned int cpu) 583 { 584 /* 585 * XXX sleazy hack: If we're being called in a lazy-cpu zone 586 * and lazy gs handling is enabled, it means we're in a 587 * context switch, and %gs has just been saved. This means we 588 * can zero it out to prevent faults on exit from the 589 * hypervisor if the next process has no %gs. Either way, it 590 * has been saved, and the new value will get loaded properly. 591 * This will go away as soon as Xen has been modified to not 592 * save/restore %gs for normal hypercalls. 593 * 594 * On x86_64, this hack is not used for %gs, because gs points 595 * to KERNEL_GS_BASE (and uses it for PDA references), so we 596 * must not zero %gs on x86_64 597 * 598 * For x86_64, we need to zero %fs, otherwise we may get an 599 * exception between the new %fs descriptor being loaded and 600 * %fs being effectively cleared at __switch_to(). 601 */ 602 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) { 603 #ifdef CONFIG_X86_32 604 lazy_load_gs(0); 605 #else 606 loadsegment(fs, 0); 607 #endif 608 } 609 610 xen_mc_batch(); 611 612 load_TLS_descriptor(t, cpu, 0); 613 load_TLS_descriptor(t, cpu, 1); 614 load_TLS_descriptor(t, cpu, 2); 615 616 xen_mc_issue(PARAVIRT_LAZY_CPU); 617 } 618 619 #ifdef CONFIG_X86_64 620 static void xen_load_gs_index(unsigned int idx) 621 { 622 if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL, idx)) 623 BUG(); 624 } 625 #endif 626 627 static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum, 628 const void *ptr) 629 { 630 xmaddr_t mach_lp = arbitrary_virt_to_machine(&dt[entrynum]); 631 u64 entry = *(u64 *)ptr; 632 633 trace_xen_cpu_write_ldt_entry(dt, entrynum, entry); 634 635 preempt_disable(); 636 637 xen_mc_flush(); 638 if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry)) 639 BUG(); 640 641 preempt_enable(); 642 } 643 644 static int cvt_gate_to_trap(int vector, const gate_desc *val, 645 struct trap_info *info) 646 { 647 unsigned long addr; 648 649 if (val->type != GATE_TRAP && val->type != GATE_INTERRUPT) 650 return 0; 651 652 info->vector = vector; 653 654 addr = gate_offset(*val); 655 #ifdef CONFIG_X86_64 656 /* 657 * Look for known traps using IST, and substitute them 658 * appropriately. The debugger ones are the only ones we care 659 * about. Xen will handle faults like double_fault, 660 * so we should never see them. Warn if 661 * there's an unexpected IST-using fault handler. 662 */ 663 if (addr == (unsigned long)debug) 664 addr = (unsigned long)xen_debug; 665 else if (addr == (unsigned long)int3) 666 addr = (unsigned long)xen_int3; 667 else if (addr == (unsigned long)stack_segment) 668 addr = (unsigned long)xen_stack_segment; 669 else if (addr == (unsigned long)double_fault || 670 addr == (unsigned long)nmi) { 671 /* Don't need to handle these */ 672 return 0; 673 #ifdef CONFIG_X86_MCE 674 } else if (addr == (unsigned long)machine_check) { 675 /* 676 * when xen hypervisor inject vMCE to guest, 677 * use native mce handler to handle it 678 */ 679 ; 680 #endif 681 } else { 682 /* Some other trap using IST? */ 683 if (WARN_ON(val->ist != 0)) 684 return 0; 685 } 686 #endif /* CONFIG_X86_64 */ 687 info->address = addr; 688 689 info->cs = gate_segment(*val); 690 info->flags = val->dpl; 691 /* interrupt gates clear IF */ 692 if (val->type == GATE_INTERRUPT) 693 info->flags |= 1 << 2; 694 695 return 1; 696 } 697 698 /* Locations of each CPU's IDT */ 699 static DEFINE_PER_CPU(struct desc_ptr, idt_desc); 700 701 /* Set an IDT entry. If the entry is part of the current IDT, then 702 also update Xen. */ 703 static void xen_write_idt_entry(gate_desc *dt, int entrynum, const gate_desc *g) 704 { 705 unsigned long p = (unsigned long)&dt[entrynum]; 706 unsigned long start, end; 707 708 trace_xen_cpu_write_idt_entry(dt, entrynum, g); 709 710 preempt_disable(); 711 712 start = __this_cpu_read(idt_desc.address); 713 end = start + __this_cpu_read(idt_desc.size) + 1; 714 715 xen_mc_flush(); 716 717 native_write_idt_entry(dt, entrynum, g); 718 719 if (p >= start && (p + 8) <= end) { 720 struct trap_info info[2]; 721 722 info[1].address = 0; 723 724 if (cvt_gate_to_trap(entrynum, g, &info[0])) 725 if (HYPERVISOR_set_trap_table(info)) 726 BUG(); 727 } 728 729 preempt_enable(); 730 } 731 732 static void xen_convert_trap_info(const struct desc_ptr *desc, 733 struct trap_info *traps) 734 { 735 unsigned in, out, count; 736 737 count = (desc->size+1) / sizeof(gate_desc); 738 BUG_ON(count > 256); 739 740 for (in = out = 0; in < count; in++) { 741 gate_desc *entry = (gate_desc*)(desc->address) + in; 742 743 if (cvt_gate_to_trap(in, entry, &traps[out])) 744 out++; 745 } 746 traps[out].address = 0; 747 } 748 749 void xen_copy_trap_info(struct trap_info *traps) 750 { 751 const struct desc_ptr *desc = &__get_cpu_var(idt_desc); 752 753 xen_convert_trap_info(desc, traps); 754 } 755 756 /* Load a new IDT into Xen. In principle this can be per-CPU, so we 757 hold a spinlock to protect the static traps[] array (static because 758 it avoids allocation, and saves stack space). */ 759 static void xen_load_idt(const struct desc_ptr *desc) 760 { 761 static DEFINE_SPINLOCK(lock); 762 static struct trap_info traps[257]; 763 764 trace_xen_cpu_load_idt(desc); 765 766 spin_lock(&lock); 767 768 __get_cpu_var(idt_desc) = *desc; 769 770 xen_convert_trap_info(desc, traps); 771 772 xen_mc_flush(); 773 if (HYPERVISOR_set_trap_table(traps)) 774 BUG(); 775 776 spin_unlock(&lock); 777 } 778 779 /* Write a GDT descriptor entry. Ignore LDT descriptors, since 780 they're handled differently. */ 781 static void xen_write_gdt_entry(struct desc_struct *dt, int entry, 782 const void *desc, int type) 783 { 784 trace_xen_cpu_write_gdt_entry(dt, entry, desc, type); 785 786 preempt_disable(); 787 788 switch (type) { 789 case DESC_LDT: 790 case DESC_TSS: 791 /* ignore */ 792 break; 793 794 default: { 795 xmaddr_t maddr = arbitrary_virt_to_machine(&dt[entry]); 796 797 xen_mc_flush(); 798 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc)) 799 BUG(); 800 } 801 802 } 803 804 preempt_enable(); 805 } 806 807 /* 808 * Version of write_gdt_entry for use at early boot-time needed to 809 * update an entry as simply as possible. 810 */ 811 static void __init xen_write_gdt_entry_boot(struct desc_struct *dt, int entry, 812 const void *desc, int type) 813 { 814 trace_xen_cpu_write_gdt_entry(dt, entry, desc, type); 815 816 switch (type) { 817 case DESC_LDT: 818 case DESC_TSS: 819 /* ignore */ 820 break; 821 822 default: { 823 xmaddr_t maddr = virt_to_machine(&dt[entry]); 824 825 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc)) 826 dt[entry] = *(struct desc_struct *)desc; 827 } 828 829 } 830 } 831 832 static void xen_load_sp0(struct tss_struct *tss, 833 struct thread_struct *thread) 834 { 835 struct multicall_space mcs; 836 837 mcs = xen_mc_entry(0); 838 MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->sp0); 839 xen_mc_issue(PARAVIRT_LAZY_CPU); 840 } 841 842 static void xen_set_iopl_mask(unsigned mask) 843 { 844 struct physdev_set_iopl set_iopl; 845 846 /* Force the change at ring 0. */ 847 set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3; 848 HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl); 849 } 850 851 static void xen_io_delay(void) 852 { 853 } 854 855 #ifdef CONFIG_X86_LOCAL_APIC 856 static unsigned long xen_set_apic_id(unsigned int x) 857 { 858 WARN_ON(1); 859 return x; 860 } 861 static unsigned int xen_get_apic_id(unsigned long x) 862 { 863 return ((x)>>24) & 0xFFu; 864 } 865 static u32 xen_apic_read(u32 reg) 866 { 867 struct xen_platform_op op = { 868 .cmd = XENPF_get_cpuinfo, 869 .interface_version = XENPF_INTERFACE_VERSION, 870 .u.pcpu_info.xen_cpuid = 0, 871 }; 872 int ret = 0; 873 874 /* Shouldn't need this as APIC is turned off for PV, and we only 875 * get called on the bootup processor. But just in case. */ 876 if (!xen_initial_domain() || smp_processor_id()) 877 return 0; 878 879 if (reg == APIC_LVR) 880 return 0x10; 881 882 if (reg != APIC_ID) 883 return 0; 884 885 ret = HYPERVISOR_dom0_op(&op); 886 if (ret) 887 return 0; 888 889 return op.u.pcpu_info.apic_id << 24; 890 } 891 892 static void xen_apic_write(u32 reg, u32 val) 893 { 894 /* Warn to see if there's any stray references */ 895 WARN_ON(1); 896 } 897 898 static u64 xen_apic_icr_read(void) 899 { 900 return 0; 901 } 902 903 static void xen_apic_icr_write(u32 low, u32 id) 904 { 905 /* Warn to see if there's any stray references */ 906 WARN_ON(1); 907 } 908 909 static void xen_apic_wait_icr_idle(void) 910 { 911 return; 912 } 913 914 static u32 xen_safe_apic_wait_icr_idle(void) 915 { 916 return 0; 917 } 918 919 static void set_xen_basic_apic_ops(void) 920 { 921 apic->read = xen_apic_read; 922 apic->write = xen_apic_write; 923 apic->icr_read = xen_apic_icr_read; 924 apic->icr_write = xen_apic_icr_write; 925 apic->wait_icr_idle = xen_apic_wait_icr_idle; 926 apic->safe_wait_icr_idle = xen_safe_apic_wait_icr_idle; 927 apic->set_apic_id = xen_set_apic_id; 928 apic->get_apic_id = xen_get_apic_id; 929 930 #ifdef CONFIG_SMP 931 apic->send_IPI_allbutself = xen_send_IPI_allbutself; 932 apic->send_IPI_mask_allbutself = xen_send_IPI_mask_allbutself; 933 apic->send_IPI_mask = xen_send_IPI_mask; 934 apic->send_IPI_all = xen_send_IPI_all; 935 apic->send_IPI_self = xen_send_IPI_self; 936 #endif 937 } 938 939 #endif 940 941 static void xen_clts(void) 942 { 943 struct multicall_space mcs; 944 945 mcs = xen_mc_entry(0); 946 947 MULTI_fpu_taskswitch(mcs.mc, 0); 948 949 xen_mc_issue(PARAVIRT_LAZY_CPU); 950 } 951 952 static DEFINE_PER_CPU(unsigned long, xen_cr0_value); 953 954 static unsigned long xen_read_cr0(void) 955 { 956 unsigned long cr0 = this_cpu_read(xen_cr0_value); 957 958 if (unlikely(cr0 == 0)) { 959 cr0 = native_read_cr0(); 960 this_cpu_write(xen_cr0_value, cr0); 961 } 962 963 return cr0; 964 } 965 966 static void xen_write_cr0(unsigned long cr0) 967 { 968 struct multicall_space mcs; 969 970 this_cpu_write(xen_cr0_value, cr0); 971 972 /* Only pay attention to cr0.TS; everything else is 973 ignored. */ 974 mcs = xen_mc_entry(0); 975 976 MULTI_fpu_taskswitch(mcs.mc, (cr0 & X86_CR0_TS) != 0); 977 978 xen_mc_issue(PARAVIRT_LAZY_CPU); 979 } 980 981 static void xen_write_cr4(unsigned long cr4) 982 { 983 cr4 &= ~X86_CR4_PGE; 984 cr4 &= ~X86_CR4_PSE; 985 986 native_write_cr4(cr4); 987 } 988 989 static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high) 990 { 991 int ret; 992 993 ret = 0; 994 995 switch (msr) { 996 #ifdef CONFIG_X86_64 997 unsigned which; 998 u64 base; 999 1000 case MSR_FS_BASE: which = SEGBASE_FS; goto set; 1001 case MSR_KERNEL_GS_BASE: which = SEGBASE_GS_USER; goto set; 1002 case MSR_GS_BASE: which = SEGBASE_GS_KERNEL; goto set; 1003 1004 set: 1005 base = ((u64)high << 32) | low; 1006 if (HYPERVISOR_set_segment_base(which, base) != 0) 1007 ret = -EIO; 1008 break; 1009 #endif 1010 1011 case MSR_STAR: 1012 case MSR_CSTAR: 1013 case MSR_LSTAR: 1014 case MSR_SYSCALL_MASK: 1015 case MSR_IA32_SYSENTER_CS: 1016 case MSR_IA32_SYSENTER_ESP: 1017 case MSR_IA32_SYSENTER_EIP: 1018 /* Fast syscall setup is all done in hypercalls, so 1019 these are all ignored. Stub them out here to stop 1020 Xen console noise. */ 1021 break; 1022 1023 case MSR_IA32_CR_PAT: 1024 if (smp_processor_id() == 0) 1025 xen_set_pat(((u64)high << 32) | low); 1026 break; 1027 1028 default: 1029 ret = native_write_msr_safe(msr, low, high); 1030 } 1031 1032 return ret; 1033 } 1034 1035 void xen_setup_shared_info(void) 1036 { 1037 if (!xen_feature(XENFEAT_auto_translated_physmap)) { 1038 set_fixmap(FIX_PARAVIRT_BOOTMAP, 1039 xen_start_info->shared_info); 1040 1041 HYPERVISOR_shared_info = 1042 (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP); 1043 } else 1044 HYPERVISOR_shared_info = 1045 (struct shared_info *)__va(xen_start_info->shared_info); 1046 1047 #ifndef CONFIG_SMP 1048 /* In UP this is as good a place as any to set up shared info */ 1049 xen_setup_vcpu_info_placement(); 1050 #endif 1051 1052 xen_setup_mfn_list_list(); 1053 } 1054 1055 /* This is called once we have the cpu_possible_mask */ 1056 void xen_setup_vcpu_info_placement(void) 1057 { 1058 int cpu; 1059 1060 for_each_possible_cpu(cpu) 1061 xen_vcpu_setup(cpu); 1062 1063 /* xen_vcpu_setup managed to place the vcpu_info within the 1064 percpu area for all cpus, so make use of it */ 1065 if (have_vcpu_info_placement) { 1066 pv_irq_ops.save_fl = __PV_IS_CALLEE_SAVE(xen_save_fl_direct); 1067 pv_irq_ops.restore_fl = __PV_IS_CALLEE_SAVE(xen_restore_fl_direct); 1068 pv_irq_ops.irq_disable = __PV_IS_CALLEE_SAVE(xen_irq_disable_direct); 1069 pv_irq_ops.irq_enable = __PV_IS_CALLEE_SAVE(xen_irq_enable_direct); 1070 pv_mmu_ops.read_cr2 = xen_read_cr2_direct; 1071 } 1072 } 1073 1074 static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf, 1075 unsigned long addr, unsigned len) 1076 { 1077 char *start, *end, *reloc; 1078 unsigned ret; 1079 1080 start = end = reloc = NULL; 1081 1082 #define SITE(op, x) \ 1083 case PARAVIRT_PATCH(op.x): \ 1084 if (have_vcpu_info_placement) { \ 1085 start = (char *)xen_##x##_direct; \ 1086 end = xen_##x##_direct_end; \ 1087 reloc = xen_##x##_direct_reloc; \ 1088 } \ 1089 goto patch_site 1090 1091 switch (type) { 1092 SITE(pv_irq_ops, irq_enable); 1093 SITE(pv_irq_ops, irq_disable); 1094 SITE(pv_irq_ops, save_fl); 1095 SITE(pv_irq_ops, restore_fl); 1096 #undef SITE 1097 1098 patch_site: 1099 if (start == NULL || (end-start) > len) 1100 goto default_patch; 1101 1102 ret = paravirt_patch_insns(insnbuf, len, start, end); 1103 1104 /* Note: because reloc is assigned from something that 1105 appears to be an array, gcc assumes it's non-null, 1106 but doesn't know its relationship with start and 1107 end. */ 1108 if (reloc > start && reloc < end) { 1109 int reloc_off = reloc - start; 1110 long *relocp = (long *)(insnbuf + reloc_off); 1111 long delta = start - (char *)addr; 1112 1113 *relocp += delta; 1114 } 1115 break; 1116 1117 default_patch: 1118 default: 1119 ret = paravirt_patch_default(type, clobbers, insnbuf, 1120 addr, len); 1121 break; 1122 } 1123 1124 return ret; 1125 } 1126 1127 static const struct pv_info xen_info __initconst = { 1128 .paravirt_enabled = 1, 1129 .shared_kernel_pmd = 0, 1130 1131 #ifdef CONFIG_X86_64 1132 .extra_user_64bit_cs = FLAT_USER_CS64, 1133 #endif 1134 1135 .name = "Xen", 1136 }; 1137 1138 static const struct pv_init_ops xen_init_ops __initconst = { 1139 .patch = xen_patch, 1140 }; 1141 1142 static const struct pv_cpu_ops xen_cpu_ops __initconst = { 1143 .cpuid = xen_cpuid, 1144 1145 .set_debugreg = xen_set_debugreg, 1146 .get_debugreg = xen_get_debugreg, 1147 1148 .clts = xen_clts, 1149 1150 .read_cr0 = xen_read_cr0, 1151 .write_cr0 = xen_write_cr0, 1152 1153 .read_cr4 = native_read_cr4, 1154 .read_cr4_safe = native_read_cr4_safe, 1155 .write_cr4 = xen_write_cr4, 1156 1157 .wbinvd = native_wbinvd, 1158 1159 .read_msr = native_read_msr_safe, 1160 .write_msr = xen_write_msr_safe, 1161 1162 .read_tsc = native_read_tsc, 1163 .read_pmc = native_read_pmc, 1164 1165 .iret = xen_iret, 1166 .irq_enable_sysexit = xen_sysexit, 1167 #ifdef CONFIG_X86_64 1168 .usergs_sysret32 = xen_sysret32, 1169 .usergs_sysret64 = xen_sysret64, 1170 #endif 1171 1172 .load_tr_desc = paravirt_nop, 1173 .set_ldt = xen_set_ldt, 1174 .load_gdt = xen_load_gdt, 1175 .load_idt = xen_load_idt, 1176 .load_tls = xen_load_tls, 1177 #ifdef CONFIG_X86_64 1178 .load_gs_index = xen_load_gs_index, 1179 #endif 1180 1181 .alloc_ldt = xen_alloc_ldt, 1182 .free_ldt = xen_free_ldt, 1183 1184 .store_gdt = native_store_gdt, 1185 .store_idt = native_store_idt, 1186 .store_tr = xen_store_tr, 1187 1188 .write_ldt_entry = xen_write_ldt_entry, 1189 .write_gdt_entry = xen_write_gdt_entry, 1190 .write_idt_entry = xen_write_idt_entry, 1191 .load_sp0 = xen_load_sp0, 1192 1193 .set_iopl_mask = xen_set_iopl_mask, 1194 .io_delay = xen_io_delay, 1195 1196 /* Xen takes care of %gs when switching to usermode for us */ 1197 .swapgs = paravirt_nop, 1198 1199 .start_context_switch = paravirt_start_context_switch, 1200 .end_context_switch = xen_end_context_switch, 1201 }; 1202 1203 static const struct pv_apic_ops xen_apic_ops __initconst = { 1204 #ifdef CONFIG_X86_LOCAL_APIC 1205 .startup_ipi_hook = paravirt_nop, 1206 #endif 1207 }; 1208 1209 static void xen_reboot(int reason) 1210 { 1211 struct sched_shutdown r = { .reason = reason }; 1212 1213 if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r)) 1214 BUG(); 1215 } 1216 1217 static void xen_restart(char *msg) 1218 { 1219 xen_reboot(SHUTDOWN_reboot); 1220 } 1221 1222 static void xen_emergency_restart(void) 1223 { 1224 xen_reboot(SHUTDOWN_reboot); 1225 } 1226 1227 static void xen_machine_halt(void) 1228 { 1229 xen_reboot(SHUTDOWN_poweroff); 1230 } 1231 1232 static void xen_machine_power_off(void) 1233 { 1234 if (pm_power_off) 1235 pm_power_off(); 1236 xen_reboot(SHUTDOWN_poweroff); 1237 } 1238 1239 static void xen_crash_shutdown(struct pt_regs *regs) 1240 { 1241 xen_reboot(SHUTDOWN_crash); 1242 } 1243 1244 static int 1245 xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr) 1246 { 1247 xen_reboot(SHUTDOWN_crash); 1248 return NOTIFY_DONE; 1249 } 1250 1251 static struct notifier_block xen_panic_block = { 1252 .notifier_call= xen_panic_event, 1253 }; 1254 1255 int xen_panic_handler_init(void) 1256 { 1257 atomic_notifier_chain_register(&panic_notifier_list, &xen_panic_block); 1258 return 0; 1259 } 1260 1261 static const struct machine_ops xen_machine_ops __initconst = { 1262 .restart = xen_restart, 1263 .halt = xen_machine_halt, 1264 .power_off = xen_machine_power_off, 1265 .shutdown = xen_machine_halt, 1266 .crash_shutdown = xen_crash_shutdown, 1267 .emergency_restart = xen_emergency_restart, 1268 }; 1269 1270 /* 1271 * Set up the GDT and segment registers for -fstack-protector. Until 1272 * we do this, we have to be careful not to call any stack-protected 1273 * function, which is most of the kernel. 1274 */ 1275 static void __init xen_setup_stackprotector(void) 1276 { 1277 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry_boot; 1278 pv_cpu_ops.load_gdt = xen_load_gdt_boot; 1279 1280 setup_stack_canary_segment(0); 1281 switch_to_new_gdt(0); 1282 1283 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry; 1284 pv_cpu_ops.load_gdt = xen_load_gdt; 1285 } 1286 1287 /* First C function to be called on Xen boot */ 1288 asmlinkage void __init xen_start_kernel(void) 1289 { 1290 struct physdev_set_iopl set_iopl; 1291 int rc; 1292 pgd_t *pgd; 1293 1294 if (!xen_start_info) 1295 return; 1296 1297 xen_domain_type = XEN_PV_DOMAIN; 1298 1299 xen_setup_machphys_mapping(); 1300 1301 /* Install Xen paravirt ops */ 1302 pv_info = xen_info; 1303 pv_init_ops = xen_init_ops; 1304 pv_cpu_ops = xen_cpu_ops; 1305 pv_apic_ops = xen_apic_ops; 1306 1307 x86_init.resources.memory_setup = xen_memory_setup; 1308 x86_init.oem.arch_setup = xen_arch_setup; 1309 x86_init.oem.banner = xen_banner; 1310 1311 xen_init_time_ops(); 1312 1313 /* 1314 * Set up some pagetable state before starting to set any ptes. 1315 */ 1316 1317 xen_init_mmu_ops(); 1318 1319 /* Prevent unwanted bits from being set in PTEs. */ 1320 __supported_pte_mask &= ~_PAGE_GLOBAL; 1321 #if 0 1322 if (!xen_initial_domain()) 1323 #endif 1324 __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD); 1325 1326 __supported_pte_mask |= _PAGE_IOMAP; 1327 1328 /* 1329 * Prevent page tables from being allocated in highmem, even 1330 * if CONFIG_HIGHPTE is enabled. 1331 */ 1332 __userpte_alloc_gfp &= ~__GFP_HIGHMEM; 1333 1334 /* Work out if we support NX */ 1335 x86_configure_nx(); 1336 1337 xen_setup_features(); 1338 1339 /* Get mfn list */ 1340 if (!xen_feature(XENFEAT_auto_translated_physmap)) 1341 xen_build_dynamic_phys_to_machine(); 1342 1343 /* 1344 * Set up kernel GDT and segment registers, mainly so that 1345 * -fstack-protector code can be executed. 1346 */ 1347 xen_setup_stackprotector(); 1348 1349 xen_init_irq_ops(); 1350 xen_init_cpuid_mask(); 1351 1352 #ifdef CONFIG_X86_LOCAL_APIC 1353 /* 1354 * set up the basic apic ops. 1355 */ 1356 set_xen_basic_apic_ops(); 1357 #endif 1358 1359 if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) { 1360 pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start; 1361 pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit; 1362 } 1363 1364 machine_ops = xen_machine_ops; 1365 1366 /* 1367 * The only reliable way to retain the initial address of the 1368 * percpu gdt_page is to remember it here, so we can go and 1369 * mark it RW later, when the initial percpu area is freed. 1370 */ 1371 xen_initial_gdt = &per_cpu(gdt_page, 0); 1372 1373 xen_smp_init(); 1374 1375 #ifdef CONFIG_ACPI_NUMA 1376 /* 1377 * The pages we from Xen are not related to machine pages, so 1378 * any NUMA information the kernel tries to get from ACPI will 1379 * be meaningless. Prevent it from trying. 1380 */ 1381 acpi_numa = -1; 1382 #endif 1383 1384 pgd = (pgd_t *)xen_start_info->pt_base; 1385 1386 /* Don't do the full vcpu_info placement stuff until we have a 1387 possible map and a non-dummy shared_info. */ 1388 per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0]; 1389 1390 local_irq_disable(); 1391 early_boot_irqs_disabled = true; 1392 1393 xen_raw_console_write("mapping kernel into physical memory\n"); 1394 pgd = xen_setup_kernel_pagetable(pgd, xen_start_info->nr_pages); 1395 1396 /* Allocate and initialize top and mid mfn levels for p2m structure */ 1397 xen_build_mfn_list_list(); 1398 1399 /* keep using Xen gdt for now; no urgent need to change it */ 1400 1401 #ifdef CONFIG_X86_32 1402 pv_info.kernel_rpl = 1; 1403 if (xen_feature(XENFEAT_supervisor_mode_kernel)) 1404 pv_info.kernel_rpl = 0; 1405 #else 1406 pv_info.kernel_rpl = 0; 1407 #endif 1408 /* set the limit of our address space */ 1409 xen_reserve_top(); 1410 1411 /* We used to do this in xen_arch_setup, but that is too late on AMD 1412 * were early_cpu_init (run before ->arch_setup()) calls early_amd_init 1413 * which pokes 0xcf8 port. 1414 */ 1415 set_iopl.iopl = 1; 1416 rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl); 1417 if (rc != 0) 1418 xen_raw_printk("physdev_op failed %d\n", rc); 1419 1420 #ifdef CONFIG_X86_32 1421 /* set up basic CPUID stuff */ 1422 cpu_detect(&new_cpu_data); 1423 new_cpu_data.hard_math = 1; 1424 new_cpu_data.wp_works_ok = 1; 1425 new_cpu_data.x86_capability[0] = cpuid_edx(1); 1426 #endif 1427 1428 /* Poke various useful things into boot_params */ 1429 boot_params.hdr.type_of_loader = (9 << 4) | 0; 1430 boot_params.hdr.ramdisk_image = xen_start_info->mod_start 1431 ? __pa(xen_start_info->mod_start) : 0; 1432 boot_params.hdr.ramdisk_size = xen_start_info->mod_len; 1433 boot_params.hdr.cmd_line_ptr = __pa(xen_start_info->cmd_line); 1434 1435 if (!xen_initial_domain()) { 1436 add_preferred_console("xenboot", 0, NULL); 1437 add_preferred_console("tty", 0, NULL); 1438 add_preferred_console("hvc", 0, NULL); 1439 if (pci_xen) 1440 x86_init.pci.arch_init = pci_xen_init; 1441 } else { 1442 const struct dom0_vga_console_info *info = 1443 (void *)((char *)xen_start_info + 1444 xen_start_info->console.dom0.info_off); 1445 1446 xen_init_vga(info, xen_start_info->console.dom0.info_size); 1447 xen_start_info->console.domU.mfn = 0; 1448 xen_start_info->console.domU.evtchn = 0; 1449 1450 xen_init_apic(); 1451 1452 /* Make sure ACS will be enabled */ 1453 pci_request_acs(); 1454 1455 xen_acpi_sleep_register(); 1456 } 1457 #ifdef CONFIG_PCI 1458 /* PCI BIOS service won't work from a PV guest. */ 1459 pci_probe &= ~PCI_PROBE_BIOS; 1460 #endif 1461 xen_raw_console_write("about to get started...\n"); 1462 1463 xen_setup_runstate_info(0); 1464 1465 /* Start the world */ 1466 #ifdef CONFIG_X86_32 1467 i386_start_kernel(); 1468 #else 1469 x86_64_start_reservations((char *)__pa_symbol(&boot_params)); 1470 #endif 1471 } 1472 1473 #ifdef CONFIG_XEN_PVHVM 1474 /* 1475 * The pfn containing the shared_info is located somewhere in RAM. This 1476 * will cause trouble if the current kernel is doing a kexec boot into a 1477 * new kernel. The new kernel (and its startup code) can not know where 1478 * the pfn is, so it can not reserve the page. The hypervisor will 1479 * continue to update the pfn, and as a result memory corruption occours 1480 * in the new kernel. 1481 * 1482 * One way to work around this issue is to allocate a page in the 1483 * xen-platform pci device's BAR memory range. But pci init is done very 1484 * late and the shared_info page is already in use very early to read 1485 * the pvclock. So moving the pfn from RAM to MMIO is racy because some 1486 * code paths on other vcpus could access the pfn during the small 1487 * window when the old pfn is moved to the new pfn. There is even a 1488 * small window were the old pfn is not backed by a mfn, and during that 1489 * time all reads return -1. 1490 * 1491 * Because it is not known upfront where the MMIO region is located it 1492 * can not be used right from the start in xen_hvm_init_shared_info. 1493 * 1494 * To minimise trouble the move of the pfn is done shortly before kexec. 1495 * This does not eliminate the race because all vcpus are still online 1496 * when the syscore_ops will be called. But hopefully there is no work 1497 * pending at this point in time. Also the syscore_op is run last which 1498 * reduces the risk further. 1499 */ 1500 1501 static struct shared_info *xen_hvm_shared_info; 1502 1503 static void xen_hvm_connect_shared_info(unsigned long pfn) 1504 { 1505 struct xen_add_to_physmap xatp; 1506 1507 xatp.domid = DOMID_SELF; 1508 xatp.idx = 0; 1509 xatp.space = XENMAPSPACE_shared_info; 1510 xatp.gpfn = pfn; 1511 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp)) 1512 BUG(); 1513 1514 } 1515 static void xen_hvm_set_shared_info(struct shared_info *sip) 1516 { 1517 int cpu; 1518 1519 HYPERVISOR_shared_info = sip; 1520 1521 /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info 1522 * page, we use it in the event channel upcall and in some pvclock 1523 * related functions. We don't need the vcpu_info placement 1524 * optimizations because we don't use any pv_mmu or pv_irq op on 1525 * HVM. 1526 * When xen_hvm_set_shared_info is run at boot time only vcpu 0 is 1527 * online but xen_hvm_set_shared_info is run at resume time too and 1528 * in that case multiple vcpus might be online. */ 1529 for_each_online_cpu(cpu) { 1530 per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu]; 1531 } 1532 } 1533 1534 /* Reconnect the shared_info pfn to a mfn */ 1535 void xen_hvm_resume_shared_info(void) 1536 { 1537 xen_hvm_connect_shared_info(__pa(xen_hvm_shared_info) >> PAGE_SHIFT); 1538 } 1539 1540 #ifdef CONFIG_KEXEC 1541 static struct shared_info *xen_hvm_shared_info_kexec; 1542 static unsigned long xen_hvm_shared_info_pfn_kexec; 1543 1544 /* Remember a pfn in MMIO space for kexec reboot */ 1545 void __devinit xen_hvm_prepare_kexec(struct shared_info *sip, unsigned long pfn) 1546 { 1547 xen_hvm_shared_info_kexec = sip; 1548 xen_hvm_shared_info_pfn_kexec = pfn; 1549 } 1550 1551 static void xen_hvm_syscore_shutdown(void) 1552 { 1553 struct xen_memory_reservation reservation = { 1554 .domid = DOMID_SELF, 1555 .nr_extents = 1, 1556 }; 1557 unsigned long prev_pfn; 1558 int rc; 1559 1560 if (!xen_hvm_shared_info_kexec) 1561 return; 1562 1563 prev_pfn = __pa(xen_hvm_shared_info) >> PAGE_SHIFT; 1564 set_xen_guest_handle(reservation.extent_start, &prev_pfn); 1565 1566 /* Move pfn to MMIO, disconnects previous pfn from mfn */ 1567 xen_hvm_connect_shared_info(xen_hvm_shared_info_pfn_kexec); 1568 1569 /* Update pointers, following hypercall is also a memory barrier */ 1570 xen_hvm_set_shared_info(xen_hvm_shared_info_kexec); 1571 1572 /* Allocate new mfn for previous pfn */ 1573 do { 1574 rc = HYPERVISOR_memory_op(XENMEM_populate_physmap, &reservation); 1575 if (rc == 0) 1576 msleep(123); 1577 } while (rc == 0); 1578 1579 /* Make sure the previous pfn is really connected to a (new) mfn */ 1580 BUG_ON(rc != 1); 1581 } 1582 1583 static struct syscore_ops xen_hvm_syscore_ops = { 1584 .shutdown = xen_hvm_syscore_shutdown, 1585 }; 1586 #endif 1587 1588 /* Use a pfn in RAM, may move to MMIO before kexec. */ 1589 static void __init xen_hvm_init_shared_info(void) 1590 { 1591 /* Remember pointer for resume */ 1592 xen_hvm_shared_info = extend_brk(PAGE_SIZE, PAGE_SIZE); 1593 xen_hvm_connect_shared_info(__pa(xen_hvm_shared_info) >> PAGE_SHIFT); 1594 xen_hvm_set_shared_info(xen_hvm_shared_info); 1595 } 1596 1597 static void __init init_hvm_pv_info(void) 1598 { 1599 int major, minor; 1600 uint32_t eax, ebx, ecx, edx, pages, msr, base; 1601 u64 pfn; 1602 1603 base = xen_cpuid_base(); 1604 cpuid(base + 1, &eax, &ebx, &ecx, &edx); 1605 1606 major = eax >> 16; 1607 minor = eax & 0xffff; 1608 printk(KERN_INFO "Xen version %d.%d.\n", major, minor); 1609 1610 cpuid(base + 2, &pages, &msr, &ecx, &edx); 1611 1612 pfn = __pa(hypercall_page); 1613 wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32)); 1614 1615 xen_setup_features(); 1616 1617 pv_info.name = "Xen HVM"; 1618 1619 xen_domain_type = XEN_HVM_DOMAIN; 1620 } 1621 1622 static int __cpuinit xen_hvm_cpu_notify(struct notifier_block *self, 1623 unsigned long action, void *hcpu) 1624 { 1625 int cpu = (long)hcpu; 1626 switch (action) { 1627 case CPU_UP_PREPARE: 1628 xen_vcpu_setup(cpu); 1629 if (xen_have_vector_callback) 1630 xen_init_lock_cpu(cpu); 1631 break; 1632 default: 1633 break; 1634 } 1635 return NOTIFY_OK; 1636 } 1637 1638 static struct notifier_block xen_hvm_cpu_notifier __cpuinitdata = { 1639 .notifier_call = xen_hvm_cpu_notify, 1640 }; 1641 1642 static void __init xen_hvm_guest_init(void) 1643 { 1644 init_hvm_pv_info(); 1645 1646 xen_hvm_init_shared_info(); 1647 #ifdef CONFIG_KEXEC 1648 register_syscore_ops(&xen_hvm_syscore_ops); 1649 #endif 1650 1651 if (xen_feature(XENFEAT_hvm_callback_vector)) 1652 xen_have_vector_callback = 1; 1653 xen_hvm_smp_init(); 1654 register_cpu_notifier(&xen_hvm_cpu_notifier); 1655 xen_unplug_emulated_devices(); 1656 x86_init.irqs.intr_init = xen_init_IRQ; 1657 xen_hvm_init_time_ops(); 1658 xen_hvm_init_mmu_ops(); 1659 } 1660 1661 static bool __init xen_hvm_platform(void) 1662 { 1663 if (xen_pv_domain()) 1664 return false; 1665 1666 if (!xen_cpuid_base()) 1667 return false; 1668 1669 return true; 1670 } 1671 1672 bool xen_hvm_need_lapic(void) 1673 { 1674 if (xen_pv_domain()) 1675 return false; 1676 if (!xen_hvm_domain()) 1677 return false; 1678 if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback) 1679 return false; 1680 return true; 1681 } 1682 EXPORT_SYMBOL_GPL(xen_hvm_need_lapic); 1683 1684 const struct hypervisor_x86 x86_hyper_xen_hvm __refconst = { 1685 .name = "Xen HVM", 1686 .detect = xen_hvm_platform, 1687 .init_platform = xen_hvm_guest_init, 1688 }; 1689 EXPORT_SYMBOL(x86_hyper_xen_hvm); 1690 #endif 1691