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 ipi_call_lock(); 84 set_cpu_online(cpu, true); 85 ipi_call_unlock(); 86 87 this_cpu_write(cpu_state, CPU_ONLINE); 88 89 wmb(); 90 91 /* We can take interrupts now: we're officially "up". */ 92 local_irq_enable(); 93 94 wmb(); /* make sure everything is out */ 95 } 96 97 static void __cpuinit cpu_bringup_and_idle(void) 98 { 99 cpu_bringup(); 100 cpu_idle(); 101 } 102 103 static int xen_smp_intr_init(unsigned int cpu) 104 { 105 int rc; 106 const char *resched_name, *callfunc_name, *debug_name; 107 108 resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu); 109 rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR, 110 cpu, 111 xen_reschedule_interrupt, 112 IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING, 113 resched_name, 114 NULL); 115 if (rc < 0) 116 goto fail; 117 per_cpu(xen_resched_irq, cpu) = rc; 118 119 callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu); 120 rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR, 121 cpu, 122 xen_call_function_interrupt, 123 IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING, 124 callfunc_name, 125 NULL); 126 if (rc < 0) 127 goto fail; 128 per_cpu(xen_callfunc_irq, cpu) = rc; 129 130 debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu); 131 rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu, xen_debug_interrupt, 132 IRQF_DISABLED | IRQF_PERCPU | IRQF_NOBALANCING, 133 debug_name, NULL); 134 if (rc < 0) 135 goto fail; 136 per_cpu(xen_debug_irq, cpu) = rc; 137 138 callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu); 139 rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR, 140 cpu, 141 xen_call_function_single_interrupt, 142 IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING, 143 callfunc_name, 144 NULL); 145 if (rc < 0) 146 goto fail; 147 per_cpu(xen_callfuncsingle_irq, cpu) = rc; 148 149 callfunc_name = kasprintf(GFP_KERNEL, "irqwork%d", cpu); 150 rc = bind_ipi_to_irqhandler(XEN_IRQ_WORK_VECTOR, 151 cpu, 152 xen_irq_work_interrupt, 153 IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING, 154 callfunc_name, 155 NULL); 156 if (rc < 0) 157 goto fail; 158 per_cpu(xen_irq_work, cpu) = rc; 159 160 return 0; 161 162 fail: 163 if (per_cpu(xen_resched_irq, cpu) >= 0) 164 unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu), NULL); 165 if (per_cpu(xen_callfunc_irq, cpu) >= 0) 166 unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu), NULL); 167 if (per_cpu(xen_debug_irq, cpu) >= 0) 168 unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu), NULL); 169 if (per_cpu(xen_callfuncsingle_irq, cpu) >= 0) 170 unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu), 171 NULL); 172 if (per_cpu(xen_irq_work, cpu) >= 0) 173 unbind_from_irqhandler(per_cpu(xen_irq_work, cpu), NULL); 174 175 return rc; 176 } 177 178 static void __init xen_fill_possible_map(void) 179 { 180 int i, rc; 181 182 if (xen_initial_domain()) 183 return; 184 185 for (i = 0; i < nr_cpu_ids; i++) { 186 rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL); 187 if (rc >= 0) { 188 num_processors++; 189 set_cpu_possible(i, true); 190 } 191 } 192 } 193 194 static void __init xen_filter_cpu_maps(void) 195 { 196 int i, rc; 197 unsigned int subtract = 0; 198 199 if (!xen_initial_domain()) 200 return; 201 202 num_processors = 0; 203 disabled_cpus = 0; 204 for (i = 0; i < nr_cpu_ids; i++) { 205 rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL); 206 if (rc >= 0) { 207 num_processors++; 208 set_cpu_possible(i, true); 209 } else { 210 set_cpu_possible(i, false); 211 set_cpu_present(i, false); 212 subtract++; 213 } 214 } 215 #ifdef CONFIG_HOTPLUG_CPU 216 /* This is akin to using 'nr_cpus' on the Linux command line. 217 * Which is OK as when we use 'dom0_max_vcpus=X' we can only 218 * have up to X, while nr_cpu_ids is greater than X. This 219 * normally is not a problem, except when CPU hotplugging 220 * is involved and then there might be more than X CPUs 221 * in the guest - which will not work as there is no 222 * hypercall to expand the max number of VCPUs an already 223 * running guest has. So cap it up to X. */ 224 if (subtract) 225 nr_cpu_ids = nr_cpu_ids - subtract; 226 #endif 227 228 } 229 230 static void __init xen_smp_prepare_boot_cpu(void) 231 { 232 BUG_ON(smp_processor_id() != 0); 233 native_smp_prepare_boot_cpu(); 234 235 /* We've switched to the "real" per-cpu gdt, so make sure the 236 old memory can be recycled */ 237 make_lowmem_page_readwrite(xen_initial_gdt); 238 239 xen_filter_cpu_maps(); 240 xen_setup_vcpu_info_placement(); 241 } 242 243 static void __init xen_smp_prepare_cpus(unsigned int max_cpus) 244 { 245 unsigned cpu; 246 unsigned int i; 247 248 if (skip_ioapic_setup) { 249 char *m = (max_cpus == 0) ? 250 "The nosmp parameter is incompatible with Xen; " \ 251 "use Xen dom0_max_vcpus=1 parameter" : 252 "The noapic parameter is incompatible with Xen"; 253 254 xen_raw_printk(m); 255 panic(m); 256 } 257 xen_init_lock_cpu(0); 258 259 smp_store_cpu_info(0); 260 cpu_data(0).x86_max_cores = 1; 261 262 for_each_possible_cpu(i) { 263 zalloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL); 264 zalloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL); 265 zalloc_cpumask_var(&per_cpu(cpu_llc_shared_map, i), GFP_KERNEL); 266 } 267 set_cpu_sibling_map(0); 268 269 if (xen_smp_intr_init(0)) 270 BUG(); 271 272 if (!alloc_cpumask_var(&xen_cpu_initialized_map, GFP_KERNEL)) 273 panic("could not allocate xen_cpu_initialized_map\n"); 274 275 cpumask_copy(xen_cpu_initialized_map, cpumask_of(0)); 276 277 /* Restrict the possible_map according to max_cpus. */ 278 while ((num_possible_cpus() > 1) && (num_possible_cpus() > max_cpus)) { 279 for (cpu = nr_cpu_ids - 1; !cpu_possible(cpu); cpu--) 280 continue; 281 set_cpu_possible(cpu, false); 282 } 283 284 for_each_possible_cpu(cpu) 285 set_cpu_present(cpu, true); 286 } 287 288 static int __cpuinit 289 cpu_initialize_context(unsigned int cpu, struct task_struct *idle) 290 { 291 struct vcpu_guest_context *ctxt; 292 struct desc_struct *gdt; 293 unsigned long gdt_mfn; 294 295 if (cpumask_test_and_set_cpu(cpu, xen_cpu_initialized_map)) 296 return 0; 297 298 ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL); 299 if (ctxt == NULL) 300 return -ENOMEM; 301 302 gdt = get_cpu_gdt_table(cpu); 303 304 ctxt->flags = VGCF_IN_KERNEL; 305 ctxt->user_regs.ds = __USER_DS; 306 ctxt->user_regs.es = __USER_DS; 307 ctxt->user_regs.ss = __KERNEL_DS; 308 #ifdef CONFIG_X86_32 309 ctxt->user_regs.fs = __KERNEL_PERCPU; 310 ctxt->user_regs.gs = __KERNEL_STACK_CANARY; 311 #else 312 ctxt->gs_base_kernel = per_cpu_offset(cpu); 313 #endif 314 ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle; 315 ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */ 316 317 memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt)); 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->user_regs.cs = __KERNEL_CS; 333 ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs); 334 335 ctxt->kernel_ss = __KERNEL_DS; 336 ctxt->kernel_sp = idle->thread.sp0; 337 338 #ifdef CONFIG_X86_32 339 ctxt->event_callback_cs = __KERNEL_CS; 340 ctxt->failsafe_callback_cs = __KERNEL_CS; 341 #endif 342 ctxt->event_callback_eip = (unsigned long)xen_hypervisor_callback; 343 ctxt->failsafe_callback_eip = (unsigned long)xen_failsafe_callback; 344 345 per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir); 346 ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir)); 347 348 if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt)) 349 BUG(); 350 351 kfree(ctxt); 352 return 0; 353 } 354 355 static int __cpuinit xen_cpu_up(unsigned int cpu, struct task_struct *idle) 356 { 357 int rc; 358 359 per_cpu(current_task, cpu) = idle; 360 #ifdef CONFIG_X86_32 361 irq_ctx_init(cpu); 362 #else 363 clear_tsk_thread_flag(idle, TIF_FORK); 364 per_cpu(kernel_stack, cpu) = 365 (unsigned long)task_stack_page(idle) - 366 KERNEL_STACK_OFFSET + THREAD_SIZE; 367 #endif 368 xen_setup_runstate_info(cpu); 369 xen_setup_timer(cpu); 370 xen_init_lock_cpu(cpu); 371 372 per_cpu(cpu_state, cpu) = CPU_UP_PREPARE; 373 374 /* make sure interrupts start blocked */ 375 per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1; 376 377 rc = cpu_initialize_context(cpu, idle); 378 if (rc) 379 return rc; 380 381 if (num_online_cpus() == 1) 382 alternatives_smp_switch(1); 383 384 rc = xen_smp_intr_init(cpu); 385 if (rc) 386 return rc; 387 388 rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL); 389 BUG_ON(rc); 390 391 while(per_cpu(cpu_state, cpu) != CPU_ONLINE) { 392 HYPERVISOR_sched_op(SCHEDOP_yield, NULL); 393 barrier(); 394 } 395 396 return 0; 397 } 398 399 static void xen_smp_cpus_done(unsigned int max_cpus) 400 { 401 } 402 403 #ifdef CONFIG_HOTPLUG_CPU 404 static int xen_cpu_disable(void) 405 { 406 unsigned int cpu = smp_processor_id(); 407 if (cpu == 0) 408 return -EBUSY; 409 410 cpu_disable_common(); 411 412 load_cr3(swapper_pg_dir); 413 return 0; 414 } 415 416 static void xen_cpu_die(unsigned int cpu) 417 { 418 while (HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL)) { 419 current->state = TASK_UNINTERRUPTIBLE; 420 schedule_timeout(HZ/10); 421 } 422 unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu), NULL); 423 unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu), NULL); 424 unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu), NULL); 425 unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu), NULL); 426 unbind_from_irqhandler(per_cpu(xen_irq_work, cpu), NULL); 427 xen_uninit_lock_cpu(cpu); 428 xen_teardown_timer(cpu); 429 430 if (num_online_cpus() == 1) 431 alternatives_smp_switch(0); 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 * Balance out the preempt calls - as we are running in cpu_idle 441 * loop which has been called at bootup from cpu_bringup_and_idle. 442 * The cpucpu_bringup_and_idle called cpu_bringup which made a 443 * preempt_disable() So this preempt_enable will balance it out. 444 */ 445 preempt_enable(); 446 } 447 448 #else /* !CONFIG_HOTPLUG_CPU */ 449 static int xen_cpu_disable(void) 450 { 451 return -ENOSYS; 452 } 453 454 static void xen_cpu_die(unsigned int cpu) 455 { 456 BUG(); 457 } 458 459 static void xen_play_dead(void) 460 { 461 BUG(); 462 } 463 464 #endif 465 static void stop_self(void *v) 466 { 467 int cpu = smp_processor_id(); 468 469 /* make sure we're not pinning something down */ 470 load_cr3(swapper_pg_dir); 471 /* should set up a minimal gdt */ 472 473 set_cpu_online(cpu, false); 474 475 HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL); 476 BUG(); 477 } 478 479 static void xen_stop_other_cpus(int wait) 480 { 481 smp_call_function(stop_self, NULL, wait); 482 } 483 484 static void xen_smp_send_reschedule(int cpu) 485 { 486 xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR); 487 } 488 489 static void __xen_send_IPI_mask(const struct cpumask *mask, 490 int vector) 491 { 492 unsigned cpu; 493 494 for_each_cpu_and(cpu, mask, cpu_online_mask) 495 xen_send_IPI_one(cpu, vector); 496 } 497 498 static void xen_smp_send_call_function_ipi(const struct cpumask *mask) 499 { 500 int cpu; 501 502 __xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR); 503 504 /* Make sure other vcpus get a chance to run if they need to. */ 505 for_each_cpu(cpu, mask) { 506 if (xen_vcpu_stolen(cpu)) { 507 HYPERVISOR_sched_op(SCHEDOP_yield, NULL); 508 break; 509 } 510 } 511 } 512 513 static void xen_smp_send_call_function_single_ipi(int cpu) 514 { 515 __xen_send_IPI_mask(cpumask_of(cpu), 516 XEN_CALL_FUNCTION_SINGLE_VECTOR); 517 } 518 519 static inline int xen_map_vector(int vector) 520 { 521 int xen_vector; 522 523 switch (vector) { 524 case RESCHEDULE_VECTOR: 525 xen_vector = XEN_RESCHEDULE_VECTOR; 526 break; 527 case CALL_FUNCTION_VECTOR: 528 xen_vector = XEN_CALL_FUNCTION_VECTOR; 529 break; 530 case CALL_FUNCTION_SINGLE_VECTOR: 531 xen_vector = XEN_CALL_FUNCTION_SINGLE_VECTOR; 532 break; 533 case IRQ_WORK_VECTOR: 534 xen_vector = XEN_IRQ_WORK_VECTOR; 535 break; 536 default: 537 xen_vector = -1; 538 printk(KERN_ERR "xen: vector 0x%x is not implemented\n", 539 vector); 540 } 541 542 return xen_vector; 543 } 544 545 void xen_send_IPI_mask(const struct cpumask *mask, 546 int vector) 547 { 548 int xen_vector = xen_map_vector(vector); 549 550 if (xen_vector >= 0) 551 __xen_send_IPI_mask(mask, xen_vector); 552 } 553 554 void xen_send_IPI_all(int vector) 555 { 556 int xen_vector = xen_map_vector(vector); 557 558 if (xen_vector >= 0) 559 __xen_send_IPI_mask(cpu_online_mask, xen_vector); 560 } 561 562 void xen_send_IPI_self(int vector) 563 { 564 int xen_vector = xen_map_vector(vector); 565 566 if (xen_vector >= 0) 567 xen_send_IPI_one(smp_processor_id(), xen_vector); 568 } 569 570 void xen_send_IPI_mask_allbutself(const struct cpumask *mask, 571 int vector) 572 { 573 unsigned cpu; 574 unsigned int this_cpu = smp_processor_id(); 575 576 if (!(num_online_cpus() > 1)) 577 return; 578 579 for_each_cpu_and(cpu, mask, cpu_online_mask) { 580 if (this_cpu == cpu) 581 continue; 582 583 xen_smp_send_call_function_single_ipi(cpu); 584 } 585 } 586 587 void xen_send_IPI_allbutself(int vector) 588 { 589 int xen_vector = xen_map_vector(vector); 590 591 if (xen_vector >= 0) 592 xen_send_IPI_mask_allbutself(cpu_online_mask, xen_vector); 593 } 594 595 static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id) 596 { 597 irq_enter(); 598 generic_smp_call_function_interrupt(); 599 inc_irq_stat(irq_call_count); 600 irq_exit(); 601 602 return IRQ_HANDLED; 603 } 604 605 static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id) 606 { 607 irq_enter(); 608 generic_smp_call_function_single_interrupt(); 609 inc_irq_stat(irq_call_count); 610 irq_exit(); 611 612 return IRQ_HANDLED; 613 } 614 615 static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id) 616 { 617 irq_enter(); 618 irq_work_run(); 619 inc_irq_stat(apic_irq_work_irqs); 620 irq_exit(); 621 622 return IRQ_HANDLED; 623 } 624 625 static const struct smp_ops xen_smp_ops __initconst = { 626 .smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu, 627 .smp_prepare_cpus = xen_smp_prepare_cpus, 628 .smp_cpus_done = xen_smp_cpus_done, 629 630 .cpu_up = xen_cpu_up, 631 .cpu_die = xen_cpu_die, 632 .cpu_disable = xen_cpu_disable, 633 .play_dead = xen_play_dead, 634 635 .stop_other_cpus = xen_stop_other_cpus, 636 .smp_send_reschedule = xen_smp_send_reschedule, 637 638 .send_call_func_ipi = xen_smp_send_call_function_ipi, 639 .send_call_func_single_ipi = xen_smp_send_call_function_single_ipi, 640 }; 641 642 void __init xen_smp_init(void) 643 { 644 smp_ops = xen_smp_ops; 645 xen_fill_possible_map(); 646 xen_init_spinlocks(); 647 } 648 649 static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus) 650 { 651 native_smp_prepare_cpus(max_cpus); 652 WARN_ON(xen_smp_intr_init(0)); 653 654 xen_init_lock_cpu(0); 655 } 656 657 static int __cpuinit xen_hvm_cpu_up(unsigned int cpu, struct task_struct *tidle) 658 { 659 int rc; 660 rc = native_cpu_up(cpu, tidle); 661 WARN_ON (xen_smp_intr_init(cpu)); 662 return rc; 663 } 664 665 static void xen_hvm_cpu_die(unsigned int cpu) 666 { 667 unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu), NULL); 668 unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu), NULL); 669 unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu), NULL); 670 unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu), NULL); 671 unbind_from_irqhandler(per_cpu(xen_irq_work, cpu), NULL); 672 native_cpu_die(cpu); 673 } 674 675 void __init xen_hvm_smp_init(void) 676 { 677 if (!xen_have_vector_callback) 678 return; 679 smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus; 680 smp_ops.smp_send_reschedule = xen_smp_send_reschedule; 681 smp_ops.cpu_up = xen_hvm_cpu_up; 682 smp_ops.cpu_die = xen_hvm_cpu_die; 683 smp_ops.send_call_func_ipi = xen_smp_send_call_function_ipi; 684 smp_ops.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi; 685 } 686