arch/arm/xen/enlighten.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 #include <xen/xen.h>
   3 #include <xen/events.h>
   4 #include <xen/grant_table.h>
   5 #include <xen/hvm.h>
   6 #include <xen/interface/vcpu.h>
   7 #include <xen/interface/xen.h>
   8 #include <xen/interface/memory.h>
   9 #include <xen/interface/hvm/params.h>
  10 #include <xen/features.h>
  11 #include <xen/platform_pci.h>
  12 #include <xen/xenbus.h>
  13 #include <xen/page.h>
  14 #include <xen/interface/sched.h>
  15 #include <xen/xen-ops.h>
  16 #include <asm/xen/hypervisor.h>
  17 #include <asm/xen/hypercall.h>
  18 #include <asm/system_misc.h>
  19 #include <asm/efi.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/irqreturn.h>
  22 #include <linux/module.h>
  23 #include <linux/of.h>
  24 #include <linux/of_fdt.h>
  25 #include <linux/of_irq.h>
  26 #include <linux/of_address.h>
  27 #include <linux/cpuidle.h>
  28 #include <linux/cpufreq.h>
  29 #include <linux/cpu.h>
  30 #include <linux/console.h>
  31 #include <linux/pvclock_gtod.h>
  32 #include <linux/reboot.h>
  33 #include <linux/time64.h>
  34 #include <linux/timekeeping.h>
  35 #include <linux/timekeeper_internal.h>
  36 #include <linux/acpi.h>
  37 #include <linux/virtio_anchor.h>
  38
  39 #include <linux/mm.h>
  40
  41 static struct start_info _xen_start_info;
  42 struct start_info *xen_start_info = &_xen_start_info;
  43 EXPORT_SYMBOL(xen_start_info);
  44
  45 enum xen_domain_type xen_domain_type = XEN_NATIVE;
  46 EXPORT_SYMBOL(xen_domain_type);
  47
  48 struct shared_info xen_dummy_shared_info;
  49 struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
  50
  51 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
  52 static struct vcpu_info __percpu *xen_vcpu_info;
  53
  54 /* Linux <-> Xen vCPU id mapping */
  55 DEFINE_PER_CPU(uint32_t, xen_vcpu_id);
  56 EXPORT_PER_CPU_SYMBOL(xen_vcpu_id);
  57
  58 /* These are unused until we support booting "pre-ballooned" */
  59 unsigned long xen_released_pages;
  60 struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
  61
  62 static __read_mostly unsigned int xen_events_irq;
  63 static __read_mostly phys_addr_t xen_grant_frames;
  64
  65 #define GRANT_TABLE_INDEX   0
  66 #define EXT_REGION_INDEX    1
  67
  68 uint32_t xen_start_flags;
  69 EXPORT_SYMBOL(xen_start_flags);
  70
  71 int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
  72                                int nr, struct page **pages)
  73 {
  74         return xen_xlate_unmap_gfn_range(vma, nr, pages);
  75 }
  76 EXPORT_SYMBOL_GPL(xen_unmap_domain_gfn_range);
  77
  78 static void xen_read_wallclock(struct timespec64 *ts)
  79 {
  80         u32 version;
  81         struct timespec64 now, ts_monotonic;
  82         struct shared_info *s = HYPERVISOR_shared_info;
  83         struct pvclock_wall_clock *wall_clock = &(s->wc);
  84
  85         /* get wallclock at system boot */
  86         do {
  87                 version = wall_clock->version;
  88                 rmb();          /* fetch version before time */
  89                 now.tv_sec  = ((uint64_t)wall_clock->sec_hi << 32) | wall_clock->sec;
  90                 now.tv_nsec = wall_clock->nsec;
  91                 rmb();          /* fetch time before checking version */
  92         } while ((wall_clock->version & 1) || (version != wall_clock->version));
  93
  94         /* time since system boot */
  95         ktime_get_ts64(&ts_monotonic);
  96         *ts = timespec64_add(now, ts_monotonic);
  97 }
  98
  99 static int xen_pvclock_gtod_notify(struct notifier_block *nb,
 100                                    unsigned long was_set, void *priv)
 101 {
 102         /* Protected by the calling core code serialization */
 103         static struct timespec64 next_sync;
 104
 105         struct xen_platform_op op;
 106         struct timespec64 now, system_time;
 107         struct timekeeper *tk = priv;
 108
 109         now.tv_sec = tk->xtime_sec;
 110         now.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
 111         system_time = timespec64_add(now, tk->wall_to_monotonic);
 112
 113         /*
 114          * We only take the expensive HV call when the clock was set
 115          * or when the 11 minutes RTC synchronization time elapsed.
 116          */
 117         if (!was_set && timespec64_compare(&now, &next_sync) < 0)
 118                 return NOTIFY_OK;
 119
 120         op.cmd = XENPF_settime64;
 121         op.u.settime64.mbz = 0;
 122         op.u.settime64.secs = now.tv_sec;
 123         op.u.settime64.nsecs = now.tv_nsec;
 124         op.u.settime64.system_time = timespec64_to_ns(&system_time);
 125         (void)HYPERVISOR_platform_op(&op);
 126
 127         /*
 128          * Move the next drift compensation time 11 minutes
 129          * ahead. That's emulating the sync_cmos_clock() update for
 130          * the hardware RTC.
 131          */
 132         next_sync = now;
 133         next_sync.tv_sec += 11 * 60;
 134
 135         return NOTIFY_OK;
 136 }
 137
 138 static struct notifier_block xen_pvclock_gtod_notifier = {
 139         .notifier_call = xen_pvclock_gtod_notify,
 140 };
 141
 142 static int xen_starting_cpu(unsigned int cpu)
 143 {
 144         struct vcpu_register_vcpu_info info;
 145         struct vcpu_info *vcpup;
 146         int err;
 147
 148         /*
 149          * VCPUOP_register_vcpu_info cannot be called twice for the same
 150          * vcpu, so if vcpu_info is already registered, just get out. This
 151          * can happen with cpu-hotplug.
 152          */
 153         if (per_cpu(xen_vcpu, cpu) != NULL)
 154                 goto after_register_vcpu_info;
 155
 156         pr_info("Xen: initializing cpu%d\n", cpu);
 157         vcpup = per_cpu_ptr(xen_vcpu_info, cpu);
 158
 159         info.mfn = percpu_to_gfn(vcpup);
 160         info.offset = xen_offset_in_page(vcpup);
 161
 162         err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, xen_vcpu_nr(cpu),
 163                                  &info);
 164         BUG_ON(err);
 165         per_cpu(xen_vcpu, cpu) = vcpup;
 166
 167 after_register_vcpu_info:
 168         enable_percpu_irq(xen_events_irq, 0);
 169         return 0;
 170 }
 171
 172 static int xen_dying_cpu(unsigned int cpu)
 173 {
 174         disable_percpu_irq(xen_events_irq);
 175         return 0;
 176 }
 177
 178 void xen_reboot(int reason)
 179 {
 180         struct sched_shutdown r = { .reason = reason };
 181         int rc;
 182
 183         rc = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
 184         BUG_ON(rc);
 185 }
 186
 187 static int xen_restart(struct notifier_block *nb, unsigned long action,
 188                        void *data)
 189 {
 190         xen_reboot(SHUTDOWN_reboot);
 191
 192         return NOTIFY_DONE;
 193 }
 194
 195 static struct notifier_block xen_restart_nb = {
 196         .notifier_call = xen_restart,
 197         .priority = 192,
 198 };
 199
 200 static void xen_power_off(void)
 201 {
 202         xen_reboot(SHUTDOWN_poweroff);
 203 }
 204
 205 static irqreturn_t xen_arm_callback(int irq, void *arg)
 206 {
 207         xen_evtchn_do_upcall();
 208         return IRQ_HANDLED;
 209 }
 210
 211 static __initdata struct {
 212         const char *compat;
 213         const char *prefix;
 214         const char *version;
 215         bool found;
 216 } hyper_node = {"xen,xen", "xen,xen-", NULL, false};
 217
 218 static int __init fdt_find_hyper_node(unsigned long node, const char *uname,
 219                                       int depth, void *data)
 220 {
 221         const void *s = NULL;
 222         int len;
 223
 224         if (depth != 1 || strcmp(uname, "hypervisor") != 0)
 225                 return 0;
 226
 227         if (of_flat_dt_is_compatible(node, hyper_node.compat))
 228                 hyper_node.found = true;
 229
 230         s = of_get_flat_dt_prop(node, "compatible", &len);
 231         if (strlen(hyper_node.prefix) + 3  < len &&
 232             !strncmp(hyper_node.prefix, s, strlen(hyper_node.prefix)))
 233                 hyper_node.version = s + strlen(hyper_node.prefix);
 234
 235         /*
 236          * Check if Xen supports EFI by checking whether there is the
 237          * "/hypervisor/uefi" node in DT. If so, runtime services are available
 238          * through proxy functions (e.g. in case of Xen dom0 EFI implementation
 239          * they call special hypercall which executes relevant EFI functions)
 240          * and that is why they are always enabled.
 241          */
 242         if (IS_ENABLED(CONFIG_XEN_EFI)) {
 243                 if ((of_get_flat_dt_subnode_by_name(node, "uefi") > 0) &&
 244                     !efi_runtime_disabled())
 245                         set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
 246         }
 247
 248         return 0;
 249 }
 250
 251 /*
 252  * see Documentation/devicetree/bindings/arm/xen.txt for the
 253  * documentation of the Xen Device Tree format.
 254  */
 255 void __init xen_early_init(void)
 256 {
 257         of_scan_flat_dt(fdt_find_hyper_node, NULL);
 258         if (!hyper_node.found) {
 259                 pr_debug("No Xen support\n");
 260                 return;
 261         }
 262
 263         if (hyper_node.version == NULL) {
 264                 pr_debug("Xen version not found\n");
 265                 return;
 266         }
 267
 268         pr_info("Xen %s support found\n", hyper_node.version);
 269
 270         xen_domain_type = XEN_HVM_DOMAIN;
 271
 272         xen_setup_features();
 273
 274         if (xen_feature(XENFEAT_dom0))
 275                 xen_start_flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
 276
 277         if (!console_set_on_cmdline && !xen_initial_domain())
 278                 add_preferred_console("hvc", 0, NULL);
 279 }
 280
 281 static void __init xen_acpi_guest_init(void)
 282 {
 283 #ifdef CONFIG_ACPI
 284         struct xen_hvm_param a;
 285         int interrupt, trigger, polarity;
 286
 287         a.domid = DOMID_SELF;
 288         a.index = HVM_PARAM_CALLBACK_IRQ;
 289
 290         if (HYPERVISOR_hvm_op(HVMOP_get_param, &a)
 291             || (a.value >> 56) != HVM_PARAM_CALLBACK_TYPE_PPI) {
 292                 xen_events_irq = 0;
 293                 return;
 294         }
 295
 296         interrupt = a.value & 0xff;
 297         trigger = ((a.value >> 8) & 0x1) ? ACPI_EDGE_SENSITIVE
 298                                          : ACPI_LEVEL_SENSITIVE;
 299         polarity = ((a.value >> 8) & 0x2) ? ACPI_ACTIVE_LOW
 300                                           : ACPI_ACTIVE_HIGH;
 301         xen_events_irq = acpi_register_gsi(NULL, interrupt, trigger, polarity);
 302 #endif
 303 }
 304
 305 #ifdef CONFIG_XEN_UNPOPULATED_ALLOC
 306 /*
 307  * A type-less specific Xen resource which contains extended regions
 308  * (unused regions of guest physical address space provided by the hypervisor).
 309  */
 310 static struct resource xen_resource = {
 311         .name = "Xen unused space",
 312 };
 313
 314 int __init arch_xen_unpopulated_init(struct resource **res)
 315 {
 316         struct device_node *np;
 317         struct resource *regs, *tmp_res;
 318         uint64_t min_gpaddr = -1, max_gpaddr = 0;
 319         unsigned int i, nr_reg = 0;
 320         int rc;
 321
 322         if (!xen_domain())
 323                 return -ENODEV;
 324
 325         if (!acpi_disabled)
 326                 return -ENODEV;
 327
 328         np = of_find_compatible_node(NULL, NULL, "xen,xen");
 329         if (WARN_ON(!np))
 330                 return -ENODEV;
 331
 332         /* Skip region 0 which is reserved for grant table space */
 333         while (of_get_address(np, nr_reg + EXT_REGION_INDEX, NULL, NULL))
 334                 nr_reg++;
 335
 336         if (!nr_reg) {
 337                 pr_err("No extended regions are found\n");
 338                 of_node_put(np);
 339                 return -EINVAL;
 340         }
 341
 342         regs = kcalloc(nr_reg, sizeof(*regs), GFP_KERNEL);
 343         if (!regs) {
 344                 of_node_put(np);
 345                 return -ENOMEM;
 346         }
 347
 348         /*
 349          * Create resource from extended regions provided by the hypervisor to be
 350          * used as unused address space for Xen scratch pages.
 351          */
 352         for (i = 0; i < nr_reg; i++) {
 353                 rc = of_address_to_resource(np, i + EXT_REGION_INDEX, &regs[i]);
 354                 if (rc)
 355                         goto err;
 356
 357                 if (max_gpaddr < regs[i].end)
 358                         max_gpaddr = regs[i].end;
 359                 if (min_gpaddr > regs[i].start)
 360                         min_gpaddr = regs[i].start;
 361         }
 362
 363         xen_resource.start = min_gpaddr;
 364         xen_resource.end = max_gpaddr;
 365
 366         /*
 367          * Mark holes between extended regions as unavailable. The rest of that
 368          * address space will be available for the allocation.
 369          */
 370         for (i = 1; i < nr_reg; i++) {
 371                 resource_size_t start, end;
 372
 373                 /* There is an overlap between regions */
 374                 if (regs[i - 1].end + 1 > regs[i].start) {
 375                         rc = -EINVAL;
 376                         goto err;
 377                 }
 378
 379                 /* There is no hole between regions */
 380                 if (regs[i - 1].end + 1 == regs[i].start)
 381                         continue;
 382
 383                 start = regs[i - 1].end + 1;
 384                 end = regs[i].start - 1;
 385
 386                 tmp_res = kzalloc(sizeof(*tmp_res), GFP_KERNEL);
 387                 if (!tmp_res) {
 388                         rc = -ENOMEM;
 389                         goto err;
 390                 }
 391
 392                 tmp_res->name = "Unavailable space";
 393                 tmp_res->start = start;
 394                 tmp_res->end = end;
 395
 396                 rc = insert_resource(&xen_resource, tmp_res);
 397                 if (rc) {
 398                         pr_err("Cannot insert resource %pR (%d)\n", tmp_res, rc);
 399                         kfree(tmp_res);
 400                         goto err;
 401                 }
 402         }
 403
 404         *res = &xen_resource;
 405
 406 err:
 407         of_node_put(np);
 408         kfree(regs);
 409         return rc;
 410 }
 411 #endif
 412
 413 static void __init xen_dt_guest_init(void)
 414 {
 415         struct device_node *xen_node;
 416         struct resource res;
 417
 418         xen_node = of_find_compatible_node(NULL, NULL, "xen,xen");
 419         if (!xen_node) {
 420                 pr_err("Xen support was detected before, but it has disappeared\n");
 421                 return;
 422         }
 423
 424         xen_events_irq = irq_of_parse_and_map(xen_node, 0);
 425
 426         if (of_address_to_resource(xen_node, GRANT_TABLE_INDEX, &res)) {
 427                 pr_err("Xen grant table region is not found\n");
 428                 of_node_put(xen_node);
 429                 return;
 430         }
 431         of_node_put(xen_node);
 432         xen_grant_frames = res.start;
 433 }
 434
 435 static int __init xen_guest_init(void)
 436 {
 437         struct xen_add_to_physmap xatp;
 438         struct shared_info *shared_info_page = NULL;
 439         int rc, cpu;
 440
 441         if (!xen_domain())
 442                 return 0;
 443
 444         if (IS_ENABLED(CONFIG_XEN_VIRTIO))
 445                 virtio_set_mem_acc_cb(xen_virtio_restricted_mem_acc);
 446
 447         if (!acpi_disabled)
 448                 xen_acpi_guest_init();
 449         else
 450                 xen_dt_guest_init();
 451
 452         if (!xen_events_irq) {
 453                 pr_err("Xen event channel interrupt not found\n");
 454                 return -ENODEV;
 455         }
 456
 457         /*
 458          * The fdt parsing codes have set EFI_RUNTIME_SERVICES if Xen EFI
 459          * parameters are found. Force enable runtime services.
 460          */
 461         if (efi_enabled(EFI_RUNTIME_SERVICES))
 462                 xen_efi_runtime_setup();
 463
 464         shared_info_page = (struct shared_info *)get_zeroed_page(GFP_KERNEL);
 465
 466         if (!shared_info_page) {
 467                 pr_err("not enough memory\n");
 468                 return -ENOMEM;
 469         }
 470         xatp.domid = DOMID_SELF;
 471         xatp.idx = 0;
 472         xatp.space = XENMAPSPACE_shared_info;
 473         xatp.gpfn = virt_to_gfn(shared_info_page);
 474         if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
 475                 BUG();
 476
 477         HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
 478
 479         /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
 480          * page, we use it in the event channel upcall and in some pvclock
 481          * related functions.
 482          * The shared info contains exactly 1 CPU (the boot CPU). The guest
 483          * is required to use VCPUOP_register_vcpu_info to place vcpu info
 484          * for secondary CPUs as they are brought up.
 485          * For uniformity we use VCPUOP_register_vcpu_info even on cpu0.
 486          */
 487         xen_vcpu_info = alloc_percpu(struct vcpu_info);
 488         if (xen_vcpu_info == NULL)
 489                 return -ENOMEM;
 490
 491         /* Direct vCPU id mapping for ARM guests. */
 492         for_each_possible_cpu(cpu)
 493                 per_cpu(xen_vcpu_id, cpu) = cpu;
 494
 495         if (!xen_grant_frames) {
 496                 xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();
 497                 rc = xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
 498                                                                                    &xen_auto_xlat_grant_frames.vaddr,
 499                                                                                    xen_auto_xlat_grant_frames.count);
 500         } else
 501                 rc = gnttab_setup_auto_xlat_frames(xen_grant_frames);
 502         if (rc) {
 503                 free_percpu(xen_vcpu_info);
 504                 return rc;
 505         }
 506         gnttab_init();
 507
 508         /*
 509          * Making sure board specific code will not set up ops for
 510          * cpu idle and cpu freq.
 511          */
 512         disable_cpuidle();
 513         disable_cpufreq();
 514
 515         xen_init_IRQ();
 516
 517         if (request_percpu_irq(xen_events_irq, xen_arm_callback,
 518                                "events", &xen_vcpu)) {
 519                 pr_err("Error request IRQ %d\n", xen_events_irq);
 520                 return -EINVAL;
 521         }
 522
 523         if (xen_initial_domain())
 524                 pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
 525
 526         return cpuhp_setup_state(CPUHP_AP_ARM_XEN_STARTING,
 527                                  "arm/xen:starting", xen_starting_cpu,
 528                                  xen_dying_cpu);
 529 }
 530 early_initcall(xen_guest_init);
 531
 532 static int xen_starting_runstate_cpu(unsigned int cpu)
 533 {
 534         xen_setup_runstate_info(cpu);
 535         return 0;
 536 }
 537
 538 static int __init xen_late_init(void)
 539 {
 540         if (!xen_domain())
 541                 return -ENODEV;
 542
 543         pm_power_off = xen_power_off;
 544         register_restart_handler(&xen_restart_nb);
 545         if (!xen_initial_domain()) {
 546                 struct timespec64 ts;
 547                 xen_read_wallclock(&ts);
 548                 do_settimeofday64(&ts);
 549         }
 550
 551         if (xen_kernel_unmapped_at_usr())
 552                 return 0;
 553
 554         xen_time_setup_guest();
 555
 556         return cpuhp_setup_state(CPUHP_AP_ARM_XEN_RUNSTATE_STARTING,
 557                                  "arm/xen_runstate:starting",
 558                                  xen_starting_runstate_cpu, NULL);
 559 }
 560 late_initcall(xen_late_init);
 561
 562
 563 /* empty stubs */
 564 void xen_arch_pre_suspend(void) { }
 565 void xen_arch_post_suspend(int suspend_cancelled) { }
 566 void xen_timer_resume(void) { }
 567 void xen_arch_resume(void) { }
 568 void xen_arch_suspend(void) { }
 569
 570
 571 /* In the hypercall.S file. */
 572 EXPORT_SYMBOL_GPL(HYPERVISOR_event_channel_op);
 573 EXPORT_SYMBOL_GPL(HYPERVISOR_grant_table_op);
 574 EXPORT_SYMBOL_GPL(HYPERVISOR_xen_version);
 575 EXPORT_SYMBOL_GPL(HYPERVISOR_console_io);
 576 EXPORT_SYMBOL_GPL(HYPERVISOR_sched_op);
 577 EXPORT_SYMBOL_GPL(HYPERVISOR_hvm_op);
 578 EXPORT_SYMBOL_GPL(HYPERVISOR_memory_op);
 579 EXPORT_SYMBOL_GPL(HYPERVISOR_physdev_op);
 580 EXPORT_SYMBOL_GPL(HYPERVISOR_vcpu_op);
 581 EXPORT_SYMBOL_GPL(HYPERVISOR_platform_op_raw);
 582 EXPORT_SYMBOL_GPL(HYPERVISOR_multicall);
 583 EXPORT_SYMBOL_GPL(HYPERVISOR_vm_assist);
 584 EXPORT_SYMBOL_GPL(HYPERVISOR_dm_op);
 585 EXPORT_SYMBOL_GPL(privcmd_call);