arch/x86/xen/smp.c

   1 /*
   2  * Xen SMP support
   3  *
   4  * This file implements the Xen versions of smp_ops.  SMP under Xen is
   5  * very straightforward.  Bringing a CPU up is simply a matter of
   6  * loading its initial context and setting it running.
   7  *
   8  * IPIs are handled through the Xen event mechanism.
   9  *
  10  * Because virtual CPUs can be scheduled onto any real CPU, there's no
  11  * useful topology information for the kernel to make use of.  As a
  12  * result, all CPUs are treated as if they're single-core and
  13  * single-threaded.
  14  */
  15 #include <linux/sched.h>
  16 #include <linux/err.h>
  17 #include <linux/slab.h>
  18 #include <linux/smp.h>
  19 #include <linux/irq_work.h>
  20
  21 #include <asm/paravirt.h>
  22 #include <asm/desc.h>
  23 #include <asm/pgtable.h>
  24 #include <asm/cpu.h>
  25
  26 #include <xen/interface/xen.h>
  27 #include <xen/interface/vcpu.h>
  28
  29 #include <asm/xen/interface.h>
  30 #include <asm/xen/hypercall.h>
  31
  32 #include <xen/xen.h>
  33 #include <xen/page.h>
  34 #include <xen/events.h>
  35
  36 #include <xen/hvc-console.h>
  37 #include "xen-ops.h"
  38 #include "mmu.h"
  39
  40 cpumask_var_t xen_cpu_initialized_map;
  41
  42 static DEFINE_PER_CPU(int, xen_resched_irq);
  43 static DEFINE_PER_CPU(int, xen_callfunc_irq);
  44 static DEFINE_PER_CPU(int, xen_callfuncsingle_irq);
  45 static DEFINE_PER_CPU(int, xen_irq_work);
  46 static DEFINE_PER_CPU(int, xen_debug_irq) = -1;
  47
  48 static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id);
  49 static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id);
  50 static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id);
  51
  52 /*
  53  * Reschedule call back.
  54  */
  55 static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id)
  56 {
  57         inc_irq_stat(irq_resched_count);
  58         scheduler_ipi();
  59
  60         return IRQ_HANDLED;
  61 }
  62
  63 static void __cpuinit cpu_bringup(void)
  64 {
  65         int cpu;
  66
  67         cpu_init();
  68         touch_softlockup_watchdog();
  69         preempt_disable();
  70
  71         xen_enable_sysenter();
  72         xen_enable_syscall();
  73
  74         cpu = smp_processor_id();
  75         smp_store_cpu_info(cpu);
  76         cpu_data(cpu).x86_max_cores = 1;
  77         set_cpu_sibling_map(cpu);
  78
  79         xen_setup_cpu_clockevents();
  80
  81         notify_cpu_starting(cpu);
  82
  83         set_cpu_online(cpu, true);
  84
  85         this_cpu_write(cpu_state, CPU_ONLINE);
  86
  87         wmb();
  88
  89         /* We can take interrupts now: we're officially "up". */
  90         local_irq_enable();
  91
  92         wmb();                  /* make sure everything is out */
  93 }
  94
  95 static void __cpuinit cpu_bringup_and_idle(void)
  96 {
  97         cpu_bringup();
  98         cpu_idle();
  99 }
 100
 101 static int xen_smp_intr_init(unsigned int cpu)
 102 {
 103         int rc;
 104         const char *resched_name, *callfunc_name, *debug_name;
 105
 106         resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu);
 107         rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
 108                                     cpu,
 109                                     xen_reschedule_interrupt,
 110                                     IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
 111                                     resched_name,
 112                                     NULL);
 113         if (rc < 0)
 114                 goto fail;
 115         per_cpu(xen_resched_irq, cpu) = rc;
 116
 117         callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu);
 118         rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR,
 119                                     cpu,
 120                                     xen_call_function_interrupt,
 121                                     IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
 122                                     callfunc_name,
 123                                     NULL);
 124         if (rc < 0)
 125                 goto fail;
 126         per_cpu(xen_callfunc_irq, cpu) = rc;
 127
 128         debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu);
 129         rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu, xen_debug_interrupt,
 130                                      IRQF_DISABLED | IRQF_PERCPU | IRQF_NOBALANCING,
 131                                      debug_name, NULL);
 132         if (rc < 0)
 133                 goto fail;
 134         per_cpu(xen_debug_irq, cpu) = rc;
 135
 136         callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu);
 137         rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR,
 138                                     cpu,
 139                                     xen_call_function_single_interrupt,
 140                                     IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
 141                                     callfunc_name,
 142                                     NULL);
 143         if (rc < 0)
 144                 goto fail;
 145         per_cpu(xen_callfuncsingle_irq, cpu) = rc;
 146
 147         callfunc_name = kasprintf(GFP_KERNEL, "irqwork%d", cpu);
 148         rc = bind_ipi_to_irqhandler(XEN_IRQ_WORK_VECTOR,
 149                                     cpu,
 150                                     xen_irq_work_interrupt,
 151                                     IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
 152                                     callfunc_name,
 153                                     NULL);
 154         if (rc < 0)
 155                 goto fail;
 156         per_cpu(xen_irq_work, cpu) = rc;
 157
 158         return 0;
 159
 160  fail:
 161         if (per_cpu(xen_resched_irq, cpu) >= 0)
 162                 unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu), NULL);
 163         if (per_cpu(xen_callfunc_irq, cpu) >= 0)
 164                 unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu), NULL);
 165         if (per_cpu(xen_debug_irq, cpu) >= 0)
 166                 unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu), NULL);
 167         if (per_cpu(xen_callfuncsingle_irq, cpu) >= 0)
 168                 unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu),
 169                                        NULL);
 170         if (per_cpu(xen_irq_work, cpu) >= 0)
 171                 unbind_from_irqhandler(per_cpu(xen_irq_work, cpu), NULL);
 172
 173         return rc;
 174 }
 175
 176 static void __init xen_fill_possible_map(void)
 177 {
 178         int i, rc;
 179
 180         if (xen_initial_domain())
 181                 return;
 182
 183         for (i = 0; i < nr_cpu_ids; i++) {
 184                 rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL);
 185                 if (rc >= 0) {
 186                         num_processors++;
 187                         set_cpu_possible(i, true);
 188                 }
 189         }
 190 }
 191
 192 static void __init xen_filter_cpu_maps(void)
 193 {
 194         int i, rc;
 195         unsigned int subtract = 0;
 196
 197         if (!xen_initial_domain())
 198                 return;
 199
 200         num_processors = 0;
 201         disabled_cpus = 0;
 202         for (i = 0; i < nr_cpu_ids; i++) {
 203                 rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL);
 204                 if (rc >= 0) {
 205                         num_processors++;
 206                         set_cpu_possible(i, true);
 207                 } else {
 208                         set_cpu_possible(i, false);
 209                         set_cpu_present(i, false);
 210                         subtract++;
 211                 }
 212         }
 213 #ifdef CONFIG_HOTPLUG_CPU
 214         /* This is akin to using 'nr_cpus' on the Linux command line.
 215          * Which is OK as when we use 'dom0_max_vcpus=X' we can only
 216          * have up to X, while nr_cpu_ids is greater than X. This
 217          * normally is not a problem, except when CPU hotplugging
 218          * is involved and then there might be more than X CPUs
 219          * in the guest - which will not work as there is no
 220          * hypercall to expand the max number of VCPUs an already
 221          * running guest has. So cap it up to X. */
 222         if (subtract)
 223                 nr_cpu_ids = nr_cpu_ids - subtract;
 224 #endif
 225
 226 }
 227
 228 static void __init xen_smp_prepare_boot_cpu(void)
 229 {
 230         BUG_ON(smp_processor_id() != 0);
 231         native_smp_prepare_boot_cpu();
 232
 233         /* We've switched to the "real" per-cpu gdt, so make sure the
 234            old memory can be recycled */
 235         make_lowmem_page_readwrite(xen_initial_gdt);
 236
 237         xen_filter_cpu_maps();
 238         xen_setup_vcpu_info_placement();
 239 }
 240
 241 static void __init xen_smp_prepare_cpus(unsigned int max_cpus)
 242 {
 243         unsigned cpu;
 244         unsigned int i;
 245
 246         if (skip_ioapic_setup) {
 247                 char *m = (max_cpus == 0) ?
 248                         "The nosmp parameter is incompatible with Xen; " \
 249                         "use Xen dom0_max_vcpus=1 parameter" :
 250                         "The noapic parameter is incompatible with Xen";
 251
 252                 xen_raw_printk(m);
 253                 panic(m);
 254         }
 255         xen_init_lock_cpu(0);
 256
 257         smp_store_boot_cpu_info();
 258         cpu_data(0).x86_max_cores = 1;
 259
 260         for_each_possible_cpu(i) {
 261                 zalloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL);
 262                 zalloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL);
 263                 zalloc_cpumask_var(&per_cpu(cpu_llc_shared_map, i), GFP_KERNEL);
 264         }
 265         set_cpu_sibling_map(0);
 266
 267         if (xen_smp_intr_init(0))
 268                 BUG();
 269
 270         if (!alloc_cpumask_var(&xen_cpu_initialized_map, GFP_KERNEL))
 271                 panic("could not allocate xen_cpu_initialized_map\n");
 272
 273         cpumask_copy(xen_cpu_initialized_map, cpumask_of(0));
 274
 275         /* Restrict the possible_map according to max_cpus. */
 276         while ((num_possible_cpus() > 1) && (num_possible_cpus() > max_cpus)) {
 277                 for (cpu = nr_cpu_ids - 1; !cpu_possible(cpu); cpu--)
 278                         continue;
 279                 set_cpu_possible(cpu, false);
 280         }
 281
 282         for_each_possible_cpu(cpu)
 283                 set_cpu_present(cpu, true);
 284 }
 285
 286 static int __cpuinit
 287 cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
 288 {
 289         struct vcpu_guest_context *ctxt;
 290         struct desc_struct *gdt;
 291         unsigned long gdt_mfn;
 292
 293         if (cpumask_test_and_set_cpu(cpu, xen_cpu_initialized_map))
 294                 return 0;
 295
 296         ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
 297         if (ctxt == NULL)
 298                 return -ENOMEM;
 299
 300         gdt = get_cpu_gdt_table(cpu);
 301
 302         ctxt->flags = VGCF_IN_KERNEL;
 303         ctxt->user_regs.ss = __KERNEL_DS;
 304 #ifdef CONFIG_X86_32
 305         ctxt->user_regs.fs = __KERNEL_PERCPU;
 306         ctxt->user_regs.gs = __KERNEL_STACK_CANARY;
 307 #else
 308         ctxt->gs_base_kernel = per_cpu_offset(cpu);
 309 #endif
 310         ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle;
 311
 312         memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt));
 313
 314         {
 315                 ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */
 316                 ctxt->user_regs.ds = __USER_DS;
 317                 ctxt->user_regs.es = __USER_DS;
 318
 319                 xen_copy_trap_info(ctxt->trap_ctxt);
 320
 321                 ctxt->ldt_ents = 0;
 322
 323                 BUG_ON((unsigned long)gdt & ~PAGE_MASK);
 324
 325                 gdt_mfn = arbitrary_virt_to_mfn(gdt);
 326                 make_lowmem_page_readonly(gdt);
 327                 make_lowmem_page_readonly(mfn_to_virt(gdt_mfn));
 328
 329                 ctxt->gdt_frames[0] = gdt_mfn;
 330                 ctxt->gdt_ents      = GDT_ENTRIES;
 331
 332                 ctxt->kernel_ss = __KERNEL_DS;
 333                 ctxt->kernel_sp = idle->thread.sp0;
 334
 335 #ifdef CONFIG_X86_32
 336                 ctxt->event_callback_cs     = __KERNEL_CS;
 337                 ctxt->failsafe_callback_cs  = __KERNEL_CS;
 338 #endif
 339                 ctxt->event_callback_eip    =
 340                                         (unsigned long)xen_hypervisor_callback;
 341                 ctxt->failsafe_callback_eip =
 342                                         (unsigned long)xen_failsafe_callback;
 343         }
 344         ctxt->user_regs.cs = __KERNEL_CS;
 345         ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);
 346
 347         per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir);
 348         ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir));
 349
 350         if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt))
 351                 BUG();
 352
 353         kfree(ctxt);
 354         return 0;
 355 }
 356
 357 static int __cpuinit xen_cpu_up(unsigned int cpu, struct task_struct *idle)
 358 {
 359         int rc;
 360
 361         per_cpu(current_task, cpu) = idle;
 362 #ifdef CONFIG_X86_32
 363         irq_ctx_init(cpu);
 364 #else
 365         clear_tsk_thread_flag(idle, TIF_FORK);
 366         per_cpu(kernel_stack, cpu) =
 367                 (unsigned long)task_stack_page(idle) -
 368                 KERNEL_STACK_OFFSET + THREAD_SIZE;
 369 #endif
 370         xen_setup_runstate_info(cpu);
 371         xen_setup_timer(cpu);
 372         xen_init_lock_cpu(cpu);
 373
 374         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 375
 376         /* make sure interrupts start blocked */
 377         per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1;
 378
 379         rc = cpu_initialize_context(cpu, idle);
 380         if (rc)
 381                 return rc;
 382
 383         if (num_online_cpus() == 1)
 384                 /* Just in case we booted with a single CPU. */
 385                 alternatives_enable_smp();
 386
 387         rc = xen_smp_intr_init(cpu);
 388         if (rc)
 389                 return rc;
 390
 391         rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL);
 392         BUG_ON(rc);
 393
 394         while(per_cpu(cpu_state, cpu) != CPU_ONLINE) {
 395                 HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
 396                 barrier();
 397         }
 398
 399         return 0;
 400 }
 401
 402 static void xen_smp_cpus_done(unsigned int max_cpus)
 403 {
 404 }
 405
 406 #ifdef CONFIG_HOTPLUG_CPU
 407 static int xen_cpu_disable(void)
 408 {
 409         unsigned int cpu = smp_processor_id();
 410         if (cpu == 0)
 411                 return -EBUSY;
 412
 413         cpu_disable_common();
 414
 415         load_cr3(swapper_pg_dir);
 416         return 0;
 417 }
 418
 419 static void xen_cpu_die(unsigned int cpu)
 420 {
 421         while (HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL)) {
 422                 current->state = TASK_UNINTERRUPTIBLE;
 423                 schedule_timeout(HZ/10);
 424         }
 425         unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu), NULL);
 426         unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu), NULL);
 427         unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu), NULL);
 428         unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu), NULL);
 429         unbind_from_irqhandler(per_cpu(xen_irq_work, cpu), NULL);
 430         xen_uninit_lock_cpu(cpu);
 431         xen_teardown_timer(cpu);
 432 }
 433
 434 static void __cpuinit xen_play_dead(void) /* used only with HOTPLUG_CPU */
 435 {
 436         play_dead_common();
 437         HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
 438         cpu_bringup();
 439 }
 440
 441 #else /* !CONFIG_HOTPLUG_CPU */
 442 static int xen_cpu_disable(void)
 443 {
 444         return -ENOSYS;
 445 }
 446
 447 static void xen_cpu_die(unsigned int cpu)
 448 {
 449         BUG();
 450 }
 451
 452 static void xen_play_dead(void)
 453 {
 454         BUG();
 455 }
 456
 457 #endif
 458 static void stop_self(void *v)
 459 {
 460         int cpu = smp_processor_id();
 461
 462         /* make sure we're not pinning something down */
 463         load_cr3(swapper_pg_dir);
 464         /* should set up a minimal gdt */
 465
 466         set_cpu_online(cpu, false);
 467
 468         HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL);
 469         BUG();
 470 }
 471
 472 static void xen_stop_other_cpus(int wait)
 473 {
 474         smp_call_function(stop_self, NULL, wait);
 475 }
 476
 477 static void xen_smp_send_reschedule(int cpu)
 478 {
 479         xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);
 480 }
 481
 482 static void __xen_send_IPI_mask(const struct cpumask *mask,
 483                               int vector)
 484 {
 485         unsigned cpu;
 486
 487         for_each_cpu_and(cpu, mask, cpu_online_mask)
 488                 xen_send_IPI_one(cpu, vector);
 489 }
 490
 491 static void xen_smp_send_call_function_ipi(const struct cpumask *mask)
 492 {
 493         int cpu;
 494
 495         __xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR);
 496
 497         /* Make sure other vcpus get a chance to run if they need to. */
 498         for_each_cpu(cpu, mask) {
 499                 if (xen_vcpu_stolen(cpu)) {
 500                         HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
 501                         break;
 502                 }
 503         }
 504 }
 505
 506 static void xen_smp_send_call_function_single_ipi(int cpu)
 507 {
 508         __xen_send_IPI_mask(cpumask_of(cpu),
 509                           XEN_CALL_FUNCTION_SINGLE_VECTOR);
 510 }
 511
 512 static inline int xen_map_vector(int vector)
 513 {
 514         int xen_vector;
 515
 516         switch (vector) {
 517         case RESCHEDULE_VECTOR:
 518                 xen_vector = XEN_RESCHEDULE_VECTOR;
 519                 break;
 520         case CALL_FUNCTION_VECTOR:
 521                 xen_vector = XEN_CALL_FUNCTION_VECTOR;
 522                 break;
 523         case CALL_FUNCTION_SINGLE_VECTOR:
 524                 xen_vector = XEN_CALL_FUNCTION_SINGLE_VECTOR;
 525                 break;
 526         case IRQ_WORK_VECTOR:
 527                 xen_vector = XEN_IRQ_WORK_VECTOR;
 528                 break;
 529         default:
 530                 xen_vector = -1;
 531                 printk(KERN_ERR "xen: vector 0x%x is not implemented\n",
 532                         vector);
 533         }
 534
 535         return xen_vector;
 536 }
 537
 538 void xen_send_IPI_mask(const struct cpumask *mask,
 539                               int vector)
 540 {
 541         int xen_vector = xen_map_vector(vector);
 542
 543         if (xen_vector >= 0)
 544                 __xen_send_IPI_mask(mask, xen_vector);
 545 }
 546
 547 void xen_send_IPI_all(int vector)
 548 {
 549         int xen_vector = xen_map_vector(vector);
 550
 551         if (xen_vector >= 0)
 552                 __xen_send_IPI_mask(cpu_online_mask, xen_vector);
 553 }
 554
 555 void xen_send_IPI_self(int vector)
 556 {
 557         int xen_vector = xen_map_vector(vector);
 558
 559         if (xen_vector >= 0)
 560                 xen_send_IPI_one(smp_processor_id(), xen_vector);
 561 }
 562
 563 void xen_send_IPI_mask_allbutself(const struct cpumask *mask,
 564                                 int vector)
 565 {
 566         unsigned cpu;
 567         unsigned int this_cpu = smp_processor_id();
 568
 569         if (!(num_online_cpus() > 1))
 570                 return;
 571
 572         for_each_cpu_and(cpu, mask, cpu_online_mask) {
 573                 if (this_cpu == cpu)
 574                         continue;
 575
 576                 xen_smp_send_call_function_single_ipi(cpu);
 577         }
 578 }
 579
 580 void xen_send_IPI_allbutself(int vector)
 581 {
 582         int xen_vector = xen_map_vector(vector);
 583
 584         if (xen_vector >= 0)
 585                 xen_send_IPI_mask_allbutself(cpu_online_mask, xen_vector);
 586 }
 587
 588 static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)
 589 {
 590         irq_enter();
 591         generic_smp_call_function_interrupt();
 592         inc_irq_stat(irq_call_count);
 593         irq_exit();
 594
 595         return IRQ_HANDLED;
 596 }
 597
 598 static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
 599 {
 600         irq_enter();
 601         generic_smp_call_function_single_interrupt();
 602         inc_irq_stat(irq_call_count);
 603         irq_exit();
 604
 605         return IRQ_HANDLED;
 606 }
 607
 608 static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id)
 609 {
 610         irq_enter();
 611         irq_work_run();
 612         inc_irq_stat(apic_irq_work_irqs);
 613         irq_exit();
 614
 615         return IRQ_HANDLED;
 616 }
 617
 618 static const struct smp_ops xen_smp_ops __initconst = {
 619         .smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu,
 620         .smp_prepare_cpus = xen_smp_prepare_cpus,
 621         .smp_cpus_done = xen_smp_cpus_done,
 622
 623         .cpu_up = xen_cpu_up,
 624         .cpu_die = xen_cpu_die,
 625         .cpu_disable = xen_cpu_disable,
 626         .play_dead = xen_play_dead,
 627
 628         .stop_other_cpus = xen_stop_other_cpus,
 629         .smp_send_reschedule = xen_smp_send_reschedule,
 630
 631         .send_call_func_ipi = xen_smp_send_call_function_ipi,
 632         .send_call_func_single_ipi = xen_smp_send_call_function_single_ipi,
 633 };
 634
 635 void __init xen_smp_init(void)
 636 {
 637         smp_ops = xen_smp_ops;
 638         xen_fill_possible_map();
 639         xen_init_spinlocks();
 640 }
 641
 642 static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
 643 {
 644         native_smp_prepare_cpus(max_cpus);
 645         WARN_ON(xen_smp_intr_init(0));
 646
 647         xen_init_lock_cpu(0);
 648 }
 649
 650 static int __cpuinit xen_hvm_cpu_up(unsigned int cpu, struct task_struct *tidle)
 651 {
 652         int rc;
 653         rc = native_cpu_up(cpu, tidle);
 654         WARN_ON (xen_smp_intr_init(cpu));
 655         return rc;
 656 }
 657
 658 static void xen_hvm_cpu_die(unsigned int cpu)
 659 {
 660         unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu), NULL);
 661         unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu), NULL);
 662         unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu), NULL);
 663         unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu), NULL);
 664         unbind_from_irqhandler(per_cpu(xen_irq_work, cpu), NULL);
 665         native_cpu_die(cpu);
 666 }
 667
 668 void __init xen_hvm_smp_init(void)
 669 {
 670         if (!xen_have_vector_callback)
 671                 return;
 672         smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus;
 673         smp_ops.smp_send_reschedule = xen_smp_send_reschedule;
 674         smp_ops.cpu_up = xen_hvm_cpu_up;
 675         smp_ops.cpu_die = xen_hvm_cpu_die;
 676         smp_ops.send_call_func_ipi = xen_smp_send_call_function_ipi;
 677         smp_ops.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi;
 678 }