git.oblomov.eu Git - linux-2.6/blob - arch/x86/xen/enlighten.c

   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/kernel.h>
  15 #include <linux/init.h>
  16 #include <linux/smp.h>
  17 #include <linux/preempt.h>
  18 #include <linux/hardirq.h>
  19 #include <linux/percpu.h>
  20 #include <linux/delay.h>
  21 #include <linux/start_kernel.h>
  22 #include <linux/sched.h>
  23 #include <linux/bootmem.h>
  24 #include <linux/module.h>
  25 #include <linux/mm.h>
  26 #include <linux/page-flags.h>
  27 #include <linux/highmem.h>
  28 #include <linux/console.h>
  29
  30 #include <xen/interface/xen.h>
  31 #include <xen/interface/version.h>
  32 #include <xen/interface/physdev.h>
  33 #include <xen/interface/vcpu.h>
  34 #include <xen/features.h>
  35 #include <xen/page.h>
  36 #include <xen/hvc-console.h>
  37
  38 #include <asm/paravirt.h>
  39 #include <asm/apic.h>
  40 #include <asm/page.h>
  41 #include <asm/xen/hypercall.h>
  42 #include <asm/xen/hypervisor.h>
  43 #include <asm/fixmap.h>
  44 #include <asm/processor.h>
  45 #include <asm/proto.h>
  46 #include <asm/msr-index.h>
  47 #include <asm/setup.h>
  48 #include <asm/desc.h>
  49 #include <asm/pgtable.h>
  50 #include <asm/tlbflush.h>
  51 #include <asm/reboot.h>
  52
  53 #include "xen-ops.h"
  54 #include "mmu.h"
  55 #include "multicalls.h"
  56
  57 EXPORT_SYMBOL_GPL(hypercall_page);
  58
  59 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
  60 DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
  61
  62 enum xen_domain_type xen_domain_type = XEN_NATIVE;
  63 EXPORT_SYMBOL_GPL(xen_domain_type);
  64
  65 struct start_info *xen_start_info;
  66 EXPORT_SYMBOL_GPL(xen_start_info);
  67
  68 struct shared_info xen_dummy_shared_info;
  69
  70 void *xen_initial_gdt;
  71
  72 /*
  73  * Point at some empty memory to start with. We map the real shared_info
  74  * page as soon as fixmap is up and running.
  75  */
  76 struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
  77
  78 /*
  79  * Flag to determine whether vcpu info placement is available on all
  80  * VCPUs.  We assume it is to start with, and then set it to zero on
  81  * the first failure.  This is because it can succeed on some VCPUs
  82  * and not others, since it can involve hypervisor memory allocation,
  83  * or because the guest failed to guarantee all the appropriate
  84  * constraints on all VCPUs (ie buffer can't cross a page boundary).
  85  *
  86  * Note that any particular CPU may be using a placed vcpu structure,
  87  * but we can only optimise if the all are.
  88  *
  89  * 0: not available, 1: available
  90  */
  91 static int have_vcpu_info_placement = 1;
  92
  93 static void xen_vcpu_setup(int cpu)
  94 {
  95         struct vcpu_register_vcpu_info info;
  96         int err;
  97         struct vcpu_info *vcpup;
  98
  99         BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
 100         per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
 101
 102         if (!have_vcpu_info_placement)
 103                 return;         /* already tested, not available */
 104
 105         vcpup = &per_cpu(xen_vcpu_info, cpu);
 106
 107         info.mfn = arbitrary_virt_to_mfn(vcpup);
 108         info.offset = offset_in_page(vcpup);
 109
 110         printk(KERN_DEBUG "trying to map vcpu_info %d at %p, mfn %llx, offset %d\n",
 111                cpu, vcpup, info.mfn, info.offset);
 112
 113         /* Check to see if the hypervisor will put the vcpu_info
 114            structure where we want it, which allows direct access via
 115            a percpu-variable. */
 116         err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
 117
 118         if (err) {
 119                 printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err);
 120                 have_vcpu_info_placement = 0;
 121         } else {
 122                 /* This cpu is using the registered vcpu info, even if
 123                    later ones fail to. */
 124                 per_cpu(xen_vcpu, cpu) = vcpup;
 125
 126                 printk(KERN_DEBUG "cpu %d using vcpu_info at %p\n",
 127                        cpu, vcpup);
 128         }
 129 }
 130
 131 /*
 132  * On restore, set the vcpu placement up again.
 133  * If it fails, then we're in a bad state, since
 134  * we can't back out from using it...
 135  */
 136 void xen_vcpu_restore(void)
 137 {
 138         if (have_vcpu_info_placement) {
 139                 int cpu;
 140
 141                 for_each_online_cpu(cpu) {
 142                         bool other_cpu = (cpu != smp_processor_id());
 143
 144                         if (other_cpu &&
 145                             HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL))
 146                                 BUG();
 147
 148                         xen_vcpu_setup(cpu);
 149
 150                         if (other_cpu &&
 151                             HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL))
 152                                 BUG();
 153                 }
 154
 155                 BUG_ON(!have_vcpu_info_placement);
 156         }
 157 }
 158
 159 static void __init xen_banner(void)
 160 {
 161         unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL);
 162         struct xen_extraversion extra;
 163         HYPERVISOR_xen_version(XENVER_extraversion, &extra);
 164
 165         printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
 166                pv_info.name);
 167         printk(KERN_INFO "Xen version: %d.%d%s%s\n",
 168                version >> 16, version & 0xffff, extra.extraversion,
 169                xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
 170 }
 171
 172 static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0;
 173 static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0;
 174
 175 static void xen_cpuid(unsigned int *ax, unsigned int *bx,
 176                       unsigned int *cx, unsigned int *dx)
 177 {
 178         unsigned maskecx = ~0;
 179         unsigned maskedx = ~0;
 180
 181         /*
 182          * Mask out inconvenient features, to try and disable as many
 183          * unsupported kernel subsystems as possible.
 184          */
 185         if (*ax == 1) {
 186                 maskecx = cpuid_leaf1_ecx_mask;
 187                 maskedx = cpuid_leaf1_edx_mask;
 188         }
 189
 190         asm(XEN_EMULATE_PREFIX "cpuid"
 191                 : "=a" (*ax),
 192                   "=b" (*bx),
 193                   "=c" (*cx),
 194                   "=d" (*dx)
 195                 : "0" (*ax), "2" (*cx));
 196
 197         *cx &= maskecx;
 198         *dx &= maskedx;
 199 }
 200
 201 static __init void xen_init_cpuid_mask(void)
 202 {
 203         unsigned int ax, bx, cx, dx;
 204
 205         cpuid_leaf1_edx_mask =
 206                 ~((1 << X86_FEATURE_MCE)  |  /* disable MCE */
 207                   (1 << X86_FEATURE_MCA)  |  /* disable MCA */
 208                   (1 << X86_FEATURE_ACC));   /* thermal monitoring */
 209
 210         if (!xen_initial_domain())
 211                 cpuid_leaf1_edx_mask &=
 212                         ~((1 << X86_FEATURE_APIC) |  /* disable local APIC */
 213                           (1 << X86_FEATURE_ACPI));  /* disable ACPI */
 214
 215         ax = 1;
 216         xen_cpuid(&ax, &bx, &cx, &dx);
 217
 218         /* cpuid claims we support xsave; try enabling it to see what happens */
 219         if (cx & (1 << (X86_FEATURE_XSAVE % 32))) {
 220                 unsigned long cr4;
 221
 222                 set_in_cr4(X86_CR4_OSXSAVE);
 223
 224                 cr4 = read_cr4();
 225
 226                 if ((cr4 & X86_CR4_OSXSAVE) == 0)
 227                         cpuid_leaf1_ecx_mask &= ~(1 << (X86_FEATURE_XSAVE % 32));
 228
 229                 clear_in_cr4(X86_CR4_OSXSAVE);
 230         }
 231 }
 232
 233 static void xen_set_debugreg(int reg, unsigned long val)
 234 {
 235         HYPERVISOR_set_debugreg(reg, val);
 236 }
 237
 238 static unsigned long xen_get_debugreg(int reg)
 239 {
 240         return HYPERVISOR_get_debugreg(reg);
 241 }
 242
 243 void xen_leave_lazy(void)
 244 {
 245         paravirt_leave_lazy(paravirt_get_lazy_mode());
 246         xen_mc_flush();
 247 }
 248
 249 static unsigned long xen_store_tr(void)
 250 {
 251         return 0;
 252 }
 253
 254 /*
 255  * Set the page permissions for a particular virtual address.  If the
 256  * address is a vmalloc mapping (or other non-linear mapping), then
 257  * find the linear mapping of the page and also set its protections to
 258  * match.
 259  */
 260 static void set_aliased_prot(void *v, pgprot_t prot)
 261 {
 262         int level;
 263         pte_t *ptep;
 264         pte_t pte;
 265         unsigned long pfn;
 266         struct page *page;
 267
 268         ptep = lookup_address((unsigned long)v, &level);
 269         BUG_ON(ptep == NULL);
 270
 271         pfn = pte_pfn(*ptep);
 272         page = pfn_to_page(pfn);
 273
 274         pte = pfn_pte(pfn, prot);
 275
 276         if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0))
 277                 BUG();
 278
 279         if (!PageHighMem(page)) {
 280                 void *av = __va(PFN_PHYS(pfn));
 281
 282                 if (av != v)
 283                         if (HYPERVISOR_update_va_mapping((unsigned long)av, pte, 0))
 284                                 BUG();
 285         } else
 286                 kmap_flush_unused();
 287 }
 288
 289 static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries)
 290 {
 291         const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
 292         int i;
 293
 294         for(i = 0; i < entries; i += entries_per_page)
 295                 set_aliased_prot(ldt + i, PAGE_KERNEL_RO);
 296 }
 297
 298 static void xen_free_ldt(struct desc_struct *ldt, unsigned entries)
 299 {
 300         const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
 301         int i;
 302
 303         for(i = 0; i < entries; i += entries_per_page)
 304                 set_aliased_prot(ldt + i, PAGE_KERNEL);
 305 }
 306
 307 static void xen_set_ldt(const void *addr, unsigned entries)
 308 {
 309         struct mmuext_op *op;
 310         struct multicall_space mcs = xen_mc_entry(sizeof(*op));
 311
 312         op = mcs.args;
 313         op->cmd = MMUEXT_SET_LDT;
 314         op->arg1.linear_addr = (unsigned long)addr;
 315         op->arg2.nr_ents = entries;
 316
 317         MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
 318
 319         xen_mc_issue(PARAVIRT_LAZY_CPU);
 320 }
 321
 322 static void xen_load_gdt(const struct desc_ptr *dtr)
 323 {
 324         unsigned long va = dtr->address;
 325         unsigned int size = dtr->size + 1;
 326         unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
 327         unsigned long frames[pages];
 328         int f;
 329
 330         /* A GDT can be up to 64k in size, which corresponds to 8192
 331            8-byte entries, or 16 4k pages.. */
 332
 333         BUG_ON(size > 65536);
 334         BUG_ON(va & ~PAGE_MASK);
 335
 336         for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
 337                 int level;
 338                 pte_t *ptep = lookup_address(va, &level);
 339                 unsigned long pfn, mfn;
 340                 void *virt;
 341
 342                 BUG_ON(ptep == NULL);
 343
 344                 pfn = pte_pfn(*ptep);
 345                 mfn = pfn_to_mfn(pfn);
 346                 virt = __va(PFN_PHYS(pfn));
 347
 348                 frames[f] = mfn;
 349
 350                 make_lowmem_page_readonly((void *)va);
 351                 make_lowmem_page_readonly(virt);
 352         }
 353
 354         if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
 355                 BUG();
 356 }
 357
 358 static void load_TLS_descriptor(struct thread_struct *t,
 359                                 unsigned int cpu, unsigned int i)
 360 {
 361         struct desc_struct *gdt = get_cpu_gdt_table(cpu);
 362         xmaddr_t maddr = arbitrary_virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]);
 363         struct multicall_space mc = __xen_mc_entry(0);
 364
 365         MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]);
 366 }
 367
 368 static void xen_load_tls(struct thread_struct *t, unsigned int cpu)
 369 {
 370         /*
 371          * XXX sleazy hack: If we're being called in a lazy-cpu zone
 372          * and lazy gs handling is enabled, it means we're in a
 373          * context switch, and %gs has just been saved.  This means we
 374          * can zero it out to prevent faults on exit from the
 375          * hypervisor if the next process has no %gs.  Either way, it
 376          * has been saved, and the new value will get loaded properly.
 377          * This will go away as soon as Xen has been modified to not
 378          * save/restore %gs for normal hypercalls.
 379          *
 380          * On x86_64, this hack is not used for %gs, because gs points
 381          * to KERNEL_GS_BASE (and uses it for PDA references), so we
 382          * must not zero %gs on x86_64
 383          *
 384          * For x86_64, we need to zero %fs, otherwise we may get an
 385          * exception between the new %fs descriptor being loaded and
 386          * %fs being effectively cleared at __switch_to().
 387          */
 388         if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) {
 389 #ifdef CONFIG_X86_32
 390                 lazy_load_gs(0);
 391 #else
 392                 loadsegment(fs, 0);
 393 #endif
 394         }
 395
 396         xen_mc_batch();
 397
 398         load_TLS_descriptor(t, cpu, 0);
 399         load_TLS_descriptor(t, cpu, 1);
 400         load_TLS_descriptor(t, cpu, 2);
 401
 402         xen_mc_issue(PARAVIRT_LAZY_CPU);
 403 }
 404
 405 #ifdef CONFIG_X86_64
 406 static void xen_load_gs_index(unsigned int idx)
 407 {
 408         if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL, idx))
 409                 BUG();
 410 }
 411 #endif
 412
 413 static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
 414                                 const void *ptr)
 415 {
 416         xmaddr_t mach_lp = arbitrary_virt_to_machine(&dt[entrynum]);
 417         u64 entry = *(u64 *)ptr;
 418
 419         preempt_disable();
 420
 421         xen_mc_flush();
 422         if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry))
 423                 BUG();
 424
 425         preempt_enable();
 426 }
 427
 428 static int cvt_gate_to_trap(int vector, const gate_desc *val,
 429                             struct trap_info *info)
 430 {
 431         if (val->type != GATE_TRAP && val->type != GATE_INTERRUPT)
 432                 return 0;
 433
 434         info->vector = vector;
 435         info->address = gate_offset(*val);
 436         info->cs = gate_segment(*val);
 437         info->flags = val->dpl;
 438         /* interrupt gates clear IF */
 439         if (val->type == GATE_INTERRUPT)
 440                 info->flags |= 1 << 2;
 441
 442         return 1;
 443 }
 444
 445 /* Locations of each CPU's IDT */
 446 static DEFINE_PER_CPU(struct desc_ptr, idt_desc);
 447
 448 /* Set an IDT entry.  If the entry is part of the current IDT, then
 449    also update Xen. */
 450 static void xen_write_idt_entry(gate_desc *dt, int entrynum, const gate_desc *g)
 451 {
 452         unsigned long p = (unsigned long)&dt[entrynum];
 453         unsigned long start, end;
 454
 455         preempt_disable();
 456
 457         start = __get_cpu_var(idt_desc).address;
 458         end = start + __get_cpu_var(idt_desc).size + 1;
 459
 460         xen_mc_flush();
 461
 462         native_write_idt_entry(dt, entrynum, g);
 463
 464         if (p >= start && (p + 8) <= end) {
 465                 struct trap_info info[2];
 466
 467                 info[1].address = 0;
 468
 469                 if (cvt_gate_to_trap(entrynum, g, &info[0]))
 470                         if (HYPERVISOR_set_trap_table(info))
 471                                 BUG();
 472         }
 473
 474         preempt_enable();
 475 }
 476
 477 static void xen_convert_trap_info(const struct desc_ptr *desc,
 478                                   struct trap_info *traps)
 479 {
 480         unsigned in, out, count;
 481
 482         count = (desc->size+1) / sizeof(gate_desc);
 483         BUG_ON(count > 256);
 484
 485         for (in = out = 0; in < count; in++) {
 486                 gate_desc *entry = (gate_desc*)(desc->address) + in;
 487
 488                 if (cvt_gate_to_trap(in, entry, &traps[out]))
 489                         out++;
 490         }
 491         traps[out].address = 0;
 492 }
 493
 494 void xen_copy_trap_info(struct trap_info *traps)
 495 {
 496         const struct desc_ptr *desc = &__get_cpu_var(idt_desc);
 497
 498         xen_convert_trap_info(desc, traps);
 499 }
 500
 501 /* Load a new IDT into Xen.  In principle this can be per-CPU, so we
 502    hold a spinlock to protect the static traps[] array (static because
 503    it avoids allocation, and saves stack space). */
 504 static void xen_load_idt(const struct desc_ptr *desc)
 505 {
 506         static DEFINE_SPINLOCK(lock);
 507         static struct trap_info traps[257];
 508
 509         spin_lock(&lock);
 510
 511         __get_cpu_var(idt_desc) = *desc;
 512
 513         xen_convert_trap_info(desc, traps);
 514
 515         xen_mc_flush();
 516         if (HYPERVISOR_set_trap_table(traps))
 517                 BUG();
 518
 519         spin_unlock(&lock);
 520 }
 521
 522 /* Write a GDT descriptor entry.  Ignore LDT descriptors, since
 523    they're handled differently. */
 524 static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
 525                                 const void *desc, int type)
 526 {
 527         preempt_disable();
 528
 529         switch (type) {
 530         case DESC_LDT:
 531         case DESC_TSS:
 532                 /* ignore */
 533                 break;
 534
 535         default: {
 536                 xmaddr_t maddr = arbitrary_virt_to_machine(&dt[entry]);
 537
 538                 xen_mc_flush();
 539                 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
 540                         BUG();
 541         }
 542
 543         }
 544
 545         preempt_enable();
 546 }
 547
 548 static void xen_load_sp0(struct tss_struct *tss,
 549                          struct thread_struct *thread)
 550 {
 551         struct multicall_space mcs = xen_mc_entry(0);
 552         MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->sp0);
 553         xen_mc_issue(PARAVIRT_LAZY_CPU);
 554 }
 555
 556 static void xen_set_iopl_mask(unsigned mask)
 557 {
 558         struct physdev_set_iopl set_iopl;
 559
 560         /* Force the change at ring 0. */
 561         set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3;
 562         HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
 563 }
 564
 565 static void xen_io_delay(void)
 566 {
 567 }
 568
 569 #ifdef CONFIG_X86_LOCAL_APIC
 570 static u32 xen_apic_read(u32 reg)
 571 {
 572         return 0;
 573 }
 574
 575 static void xen_apic_write(u32 reg, u32 val)
 576 {
 577         /* Warn to see if there's any stray references */
 578         WARN_ON(1);
 579 }
 580
 581 static u64 xen_apic_icr_read(void)
 582 {
 583         return 0;
 584 }
 585
 586 static void xen_apic_icr_write(u32 low, u32 id)
 587 {
 588         /* Warn to see if there's any stray references */
 589         WARN_ON(1);
 590 }
 591
 592 static void xen_apic_wait_icr_idle(void)
 593 {
 594         return;
 595 }
 596
 597 static u32 xen_safe_apic_wait_icr_idle(void)
 598 {
 599         return 0;
 600 }
 601
 602 static void set_xen_basic_apic_ops(void)
 603 {
 604         apic->read = xen_apic_read;
 605         apic->write = xen_apic_write;
 606         apic->icr_read = xen_apic_icr_read;
 607         apic->icr_write = xen_apic_icr_write;
 608         apic->wait_icr_idle = xen_apic_wait_icr_idle;
 609         apic->safe_wait_icr_idle = xen_safe_apic_wait_icr_idle;
 610 }
 611
 612 #endif
 613
 614
 615 static void xen_clts(void)
 616 {
 617         struct multicall_space mcs;
 618
 619         mcs = xen_mc_entry(0);
 620
 621         MULTI_fpu_taskswitch(mcs.mc, 0);
 622
 623         xen_mc_issue(PARAVIRT_LAZY_CPU);
 624 }
 625
 626 static void xen_write_cr0(unsigned long cr0)
 627 {
 628         struct multicall_space mcs;
 629
 630         /* Only pay attention to cr0.TS; everything else is
 631            ignored. */
 632         mcs = xen_mc_entry(0);
 633
 634         MULTI_fpu_taskswitch(mcs.mc, (cr0 & X86_CR0_TS) != 0);
 635
 636         xen_mc_issue(PARAVIRT_LAZY_CPU);
 637 }
 638
 639 static void xen_write_cr4(unsigned long cr4)
 640 {
 641         cr4 &= ~X86_CR4_PGE;
 642         cr4 &= ~X86_CR4_PSE;
 643
 644         native_write_cr4(cr4);
 645 }
 646
 647 static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
 648 {
 649         int ret;
 650
 651         ret = 0;
 652
 653         switch (msr) {
 654 #ifdef CONFIG_X86_64
 655                 unsigned which;
 656                 u64 base;
 657
 658         case MSR_FS_BASE:               which = SEGBASE_FS; goto set;
 659         case MSR_KERNEL_GS_BASE:        which = SEGBASE_GS_USER; goto set;
 660         case MSR_GS_BASE:               which = SEGBASE_GS_KERNEL; goto set;
 661
 662         set:
 663                 base = ((u64)high << 32) | low;
 664                 if (HYPERVISOR_set_segment_base(which, base) != 0)
 665                         ret = -EFAULT;
 666                 break;
 667 #endif
 668
 669         case MSR_STAR:
 670         case MSR_CSTAR:
 671         case MSR_LSTAR:
 672         case MSR_SYSCALL_MASK:
 673         case MSR_IA32_SYSENTER_CS:
 674         case MSR_IA32_SYSENTER_ESP:
 675         case MSR_IA32_SYSENTER_EIP:
 676                 /* Fast syscall setup is all done in hypercalls, so
 677                    these are all ignored.  Stub them out here to stop
 678                    Xen console noise. */
 679                 break;
 680
 681         default:
 682                 ret = native_write_msr_safe(msr, low, high);
 683         }
 684
 685         return ret;
 686 }
 687
 688 void xen_setup_shared_info(void)
 689 {
 690         if (!xen_feature(XENFEAT_auto_translated_physmap)) {
 691                 set_fixmap(FIX_PARAVIRT_BOOTMAP,
 692                            xen_start_info->shared_info);
 693
 694                 HYPERVISOR_shared_info =
 695                         (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
 696         } else
 697                 HYPERVISOR_shared_info =
 698                         (struct shared_info *)__va(xen_start_info->shared_info);
 699
 700 #ifndef CONFIG_SMP
 701         /* In UP this is as good a place as any to set up shared info */
 702         xen_setup_vcpu_info_placement();
 703 #endif
 704
 705         xen_setup_mfn_list_list();
 706 }
 707
 708 /* This is called once we have the cpu_possible_map */
 709 void xen_setup_vcpu_info_placement(void)
 710 {
 711         int cpu;
 712
 713         for_each_possible_cpu(cpu)
 714                 xen_vcpu_setup(cpu);
 715
 716         /* xen_vcpu_setup managed to place the vcpu_info within the
 717            percpu area for all cpus, so make use of it */
 718         if (have_vcpu_info_placement) {
 719                 printk(KERN_INFO "Xen: using vcpu_info placement\n");
 720
 721                 pv_irq_ops.save_fl = __PV_IS_CALLEE_SAVE(xen_save_fl_direct);
 722                 pv_irq_ops.restore_fl = __PV_IS_CALLEE_SAVE(xen_restore_fl_direct);
 723                 pv_irq_ops.irq_disable = __PV_IS_CALLEE_SAVE(xen_irq_disable_direct);
 724                 pv_irq_ops.irq_enable = __PV_IS_CALLEE_SAVE(xen_irq_enable_direct);
 725                 pv_mmu_ops.read_cr2 = xen_read_cr2_direct;
 726         }
 727 }
 728
 729 static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
 730                           unsigned long addr, unsigned len)
 731 {
 732         char *start, *end, *reloc;
 733         unsigned ret;
 734
 735         start = end = reloc = NULL;
 736
 737 #define SITE(op, x)                                                     \
 738         case PARAVIRT_PATCH(op.x):                                      \
 739         if (have_vcpu_info_placement) {                                 \
 740                 start = (char *)xen_##x##_direct;                       \
 741                 end = xen_##x##_direct_end;                             \
 742                 reloc = xen_##x##_direct_reloc;                         \
 743         }                                                               \
 744         goto patch_site
 745
 746         switch (type) {
 747                 SITE(pv_irq_ops, irq_enable);
 748                 SITE(pv_irq_ops, irq_disable);
 749                 SITE(pv_irq_ops, save_fl);
 750                 SITE(pv_irq_ops, restore_fl);
 751 #undef SITE
 752
 753         patch_site:
 754                 if (start == NULL || (end-start) > len)
 755                         goto default_patch;
 756
 757                 ret = paravirt_patch_insns(insnbuf, len, start, end);
 758
 759                 /* Note: because reloc is assigned from something that
 760                    appears to be an array, gcc assumes it's non-null,
 761                    but doesn't know its relationship with start and
 762                    end. */
 763                 if (reloc > start && reloc < end) {
 764                         int reloc_off = reloc - start;
 765                         long *relocp = (long *)(insnbuf + reloc_off);
 766                         long delta = start - (char *)addr;
 767
 768                         *relocp += delta;
 769                 }
 770                 break;
 771
 772         default_patch:
 773         default:
 774                 ret = paravirt_patch_default(type, clobbers, insnbuf,
 775                                              addr, len);
 776                 break;
 777         }
 778
 779         return ret;
 780 }
 781
 782 static const struct pv_info xen_info __initdata = {
 783         .paravirt_enabled = 1,
 784         .shared_kernel_pmd = 0,
 785
 786         .name = "Xen",
 787 };
 788
 789 static const struct pv_init_ops xen_init_ops __initdata = {
 790         .patch = xen_patch,
 791
 792         .banner = xen_banner,
 793         .memory_setup = xen_memory_setup,
 794         .arch_setup = xen_arch_setup,
 795         .post_allocator_init = xen_post_allocator_init,
 796 };
 797
 798 static const struct pv_time_ops xen_time_ops __initdata = {
 799         .time_init = xen_time_init,
 800
 801         .set_wallclock = xen_set_wallclock,
 802         .get_wallclock = xen_get_wallclock,
 803         .get_tsc_khz = xen_tsc_khz,
 804         .sched_clock = xen_sched_clock,
 805 };
 806
 807 static const struct pv_cpu_ops xen_cpu_ops __initdata = {
 808         .cpuid = xen_cpuid,
 809
 810         .set_debugreg = xen_set_debugreg,
 811         .get_debugreg = xen_get_debugreg,
 812
 813         .clts = xen_clts,
 814
 815         .read_cr0 = native_read_cr0,
 816         .write_cr0 = xen_write_cr0,
 817
 818         .read_cr4 = native_read_cr4,
 819         .read_cr4_safe = native_read_cr4_safe,
 820         .write_cr4 = xen_write_cr4,
 821
 822         .wbinvd = native_wbinvd,
 823
 824         .read_msr = native_read_msr_safe,
 825         .write_msr = xen_write_msr_safe,
 826         .read_tsc = native_read_tsc,
 827         .read_pmc = native_read_pmc,
 828
 829         .iret = xen_iret,
 830         .irq_enable_sysexit = xen_sysexit,
 831 #ifdef CONFIG_X86_64
 832         .usergs_sysret32 = xen_sysret32,
 833         .usergs_sysret64 = xen_sysret64,
 834 #endif
 835
 836         .load_tr_desc = paravirt_nop,
 837         .set_ldt = xen_set_ldt,
 838         .load_gdt = xen_load_gdt,
 839         .load_idt = xen_load_idt,
 840         .load_tls = xen_load_tls,
 841 #ifdef CONFIG_X86_64
 842         .load_gs_index = xen_load_gs_index,
 843 #endif
 844
 845         .alloc_ldt = xen_alloc_ldt,
 846         .free_ldt = xen_free_ldt,
 847
 848         .store_gdt = native_store_gdt,
 849         .store_idt = native_store_idt,
 850         .store_tr = xen_store_tr,
 851
 852         .write_ldt_entry = xen_write_ldt_entry,
 853         .write_gdt_entry = xen_write_gdt_entry,
 854         .write_idt_entry = xen_write_idt_entry,
 855         .load_sp0 = xen_load_sp0,
 856
 857         .set_iopl_mask = xen_set_iopl_mask,
 858         .io_delay = xen_io_delay,
 859
 860         /* Xen takes care of %gs when switching to usermode for us */
 861         .swapgs = paravirt_nop,
 862
 863         .lazy_mode = {
 864                 .enter = paravirt_enter_lazy_cpu,
 865                 .leave = xen_leave_lazy,
 866         },
 867 };
 868
 869 static const struct pv_apic_ops xen_apic_ops __initdata = {
 870 #ifdef CONFIG_X86_LOCAL_APIC
 871         .setup_boot_clock = paravirt_nop,
 872         .setup_secondary_clock = paravirt_nop,
 873         .startup_ipi_hook = paravirt_nop,
 874 #endif
 875 };
 876
 877 static void xen_reboot(int reason)
 878 {
 879         struct sched_shutdown r = { .reason = reason };
 880
 881 #ifdef CONFIG_SMP
 882         smp_send_stop();
 883 #endif
 884
 885         if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r))
 886                 BUG();
 887 }
 888
 889 static void xen_restart(char *msg)
 890 {
 891         xen_reboot(SHUTDOWN_reboot);
 892 }
 893
 894 static void xen_emergency_restart(void)
 895 {
 896         xen_reboot(SHUTDOWN_reboot);
 897 }
 898
 899 static void xen_machine_halt(void)
 900 {
 901         xen_reboot(SHUTDOWN_poweroff);
 902 }
 903
 904 static void xen_crash_shutdown(struct pt_regs *regs)
 905 {
 906         xen_reboot(SHUTDOWN_crash);
 907 }
 908
 909 static const struct machine_ops __initdata xen_machine_ops = {
 910         .restart = xen_restart,
 911         .halt = xen_machine_halt,
 912         .power_off = xen_machine_halt,
 913         .shutdown = xen_machine_halt,
 914         .crash_shutdown = xen_crash_shutdown,
 915         .emergency_restart = xen_emergency_restart,
 916 };
 917
 918 /* First C function to be called on Xen boot */
 919 asmlinkage void __init xen_start_kernel(void)
 920 {
 921         pgd_t *pgd;
 922
 923         if (!xen_start_info)
 924                 return;
 925
 926         xen_domain_type = XEN_PV_DOMAIN;
 927
 928         BUG_ON(memcmp(xen_start_info->magic, "xen-3", 5) != 0);
 929
 930         xen_setup_features();
 931
 932         /* Install Xen paravirt ops */
 933         pv_info = xen_info;
 934         pv_init_ops = xen_init_ops;
 935         pv_time_ops = xen_time_ops;
 936         pv_cpu_ops = xen_cpu_ops;
 937         pv_apic_ops = xen_apic_ops;
 938         pv_mmu_ops = xen_mmu_ops;
 939
 940         xen_init_irq_ops();
 941
 942         xen_init_cpuid_mask();
 943
 944 #ifdef CONFIG_X86_LOCAL_APIC
 945         /*
 946          * set up the basic apic ops.
 947          */
 948         set_xen_basic_apic_ops();
 949 #endif
 950
 951         if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
 952                 pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start;
 953                 pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit;
 954         }
 955
 956         machine_ops = xen_machine_ops;
 957
 958 #ifdef CONFIG_X86_64
 959         /*
 960          * Setup percpu state.  We only need to do this for 64-bit
 961          * because 32-bit already has %fs set properly.
 962          */
 963         load_percpu_segment(0);
 964 #endif
 965         /*
 966          * The only reliable way to retain the initial address of the
 967          * percpu gdt_page is to remember it here, so we can go and
 968          * mark it RW later, when the initial percpu area is freed.
 969          */
 970         xen_initial_gdt = &per_cpu(gdt_page, 0);
 971
 972         xen_smp_init();
 973
 974         /* Get mfn list */
 975         if (!xen_feature(XENFEAT_auto_translated_physmap))
 976                 xen_build_dynamic_phys_to_machine();
 977
 978         pgd = (pgd_t *)xen_start_info->pt_base;
 979
 980         /* Prevent unwanted bits from being set in PTEs. */
 981         __supported_pte_mask &= ~_PAGE_GLOBAL;
 982         if (!xen_initial_domain())
 983                 __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
 984
 985 #ifdef CONFIG_X86_64
 986         /* Work out if we support NX */
 987         check_efer();
 988 #endif
 989
 990         /* Don't do the full vcpu_info placement stuff until we have a
 991            possible map and a non-dummy shared_info. */
 992         per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
 993
 994         local_irq_disable();
 995         early_boot_irqs_off();
 996
 997         xen_raw_console_write("mapping kernel into physical memory\n");
 998         pgd = xen_setup_kernel_pagetable(pgd, xen_start_info->nr_pages);
 999
1000         init_mm.pgd = pgd;
1001
1002         /* keep using Xen gdt for now; no urgent need to change it */
1003
1004         pv_info.kernel_rpl = 1;
1005         if (xen_feature(XENFEAT_supervisor_mode_kernel))
1006                 pv_info.kernel_rpl = 0;
1007
1008         /* set the limit of our address space */
1009         xen_reserve_top();
1010
1011 #ifdef CONFIG_X86_32
1012         /* set up basic CPUID stuff */
1013         cpu_detect(&new_cpu_data);
1014         new_cpu_data.hard_math = 1;
1015         new_cpu_data.x86_capability[0] = cpuid_edx(1);
1016 #endif
1017
1018         /* Poke various useful things into boot_params */
1019         boot_params.hdr.type_of_loader = (9 << 4) | 0;
1020         boot_params.hdr.ramdisk_image = xen_start_info->mod_start
1021                 ? __pa(xen_start_info->mod_start) : 0;
1022         boot_params.hdr.ramdisk_size = xen_start_info->mod_len;
1023         boot_params.hdr.cmd_line_ptr = __pa(xen_start_info->cmd_line);
1024
1025         if (!xen_initial_domain()) {
1026                 add_preferred_console("xenboot", 0, NULL);
1027                 add_preferred_console("tty", 0, NULL);
1028                 add_preferred_console("hvc", 0, NULL);
1029         }
1030
1031         xen_raw_console_write("about to get started...\n");
1032
1033         /* Start the world */
1034 #ifdef CONFIG_X86_32
1035         i386_start_kernel();
1036 #else
1037         x86_64_start_reservations((char *)__pa_symbol(&boot_params));
1038 #endif
1039 }