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         if (!xen_kernel_unmapped_at_usr())
 168                 xen_setup_runstate_info(cpu);
 169
 170 after_register_vcpu_info:
 171         enable_percpu_irq(xen_events_irq, 0);
 172         return 0;
 173 }
 174
 175 static int xen_dying_cpu(unsigned int cpu)
 176 {
 177         disable_percpu_irq(xen_events_irq);
 178         return 0;
 179 }
 180
 181 void xen_reboot(int reason)
 182 {
 183         struct sched_shutdown r = { .reason = reason };
 184         int rc;
 185
 186         rc = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
 187         BUG_ON(rc);
 188 }
 189
 190 static int xen_restart(struct notifier_block *nb, unsigned long action,
 191                        void *data)
 192 {
 193         xen_reboot(SHUTDOWN_reboot);
 194
 195         return NOTIFY_DONE;
 196 }
 197
 198 static struct notifier_block xen_restart_nb = {
 199         .notifier_call = xen_restart,
 200         .priority = 192,
 201 };
 202
 203 static void xen_power_off(void)
 204 {
 205         xen_reboot(SHUTDOWN_poweroff);
 206 }
 207
 208 static irqreturn_t xen_arm_callback(int irq, void *arg)
 209 {
 210         xen_evtchn_do_upcall();
 211         return IRQ_HANDLED;
 212 }
 213
 214 static __initdata struct {
 215         const char *compat;
 216         const char *prefix;
 217         const char *version;
 218         bool found;
 219 } hyper_node = {"xen,xen", "xen,xen-", NULL, false};
 220
 221 static int __init fdt_find_hyper_node(unsigned long node, const char *uname,
 222                                       int depth, void *data)
 223 {
 224         const void *s = NULL;
 225         int len;
 226
 227         if (depth != 1 || strcmp(uname, "hypervisor") != 0)
 228                 return 0;
 229
 230         if (of_flat_dt_is_compatible(node, hyper_node.compat))
 231                 hyper_node.found = true;
 232
 233         s = of_get_flat_dt_prop(node, "compatible", &len);
 234         if (strlen(hyper_node.prefix) + 3  < len &&
 235             !strncmp(hyper_node.prefix, s, strlen(hyper_node.prefix)))
 236                 hyper_node.version = s + strlen(hyper_node.prefix);
 237
 238         /*
 239          * Check if Xen supports EFI by checking whether there is the
 240          * "/hypervisor/uefi" node in DT. If so, runtime services are available
 241          * through proxy functions (e.g. in case of Xen dom0 EFI implementation
 242          * they call special hypercall which executes relevant EFI functions)
 243          * and that is why they are always enabled.
 244          */
 245         if (IS_ENABLED(CONFIG_XEN_EFI)) {
 246                 if ((of_get_flat_dt_subnode_by_name(node, "uefi") > 0) &&
 247                     !efi_runtime_disabled())
 248                         set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
 249         }
 250
 251         return 0;
 252 }
 253
 254 /*
 255  * see Documentation/devicetree/bindings/arm/xen.txt for the
 256  * documentation of the Xen Device Tree format.
 257  */
 258 void __init xen_early_init(void)
 259 {
 260         of_scan_flat_dt(fdt_find_hyper_node, NULL);
 261         if (!hyper_node.found) {
 262                 pr_debug("No Xen support\n");
 263                 return;
 264         }
 265
 266         if (hyper_node.version == NULL) {
 267                 pr_debug("Xen version not found\n");
 268                 return;
 269         }
 270
 271         pr_info("Xen %s support found\n", hyper_node.version);
 272
 273         xen_domain_type = XEN_HVM_DOMAIN;
 274
 275         xen_setup_features();
 276
 277         if (xen_feature(XENFEAT_dom0))
 278                 xen_start_flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
 279
 280         if (!console_set_on_cmdline && !xen_initial_domain())
 281                 add_preferred_console("hvc", 0, NULL);
 282 }
 283
 284 static void __init xen_acpi_guest_init(void)
 285 {
 286 #ifdef CONFIG_ACPI
 287         struct xen_hvm_param a;
 288         int interrupt, trigger, polarity;
 289
 290         a.domid = DOMID_SELF;
 291         a.index = HVM_PARAM_CALLBACK_IRQ;
 292
 293         if (HYPERVISOR_hvm_op(HVMOP_get_param, &a)
 294             || (a.value >> 56) != HVM_PARAM_CALLBACK_TYPE_PPI) {
 295                 xen_events_irq = 0;
 296                 return;
 297         }
 298
 299         interrupt = a.value & 0xff;
 300         trigger = ((a.value >> 8) & 0x1) ? ACPI_EDGE_SENSITIVE
 301                                          : ACPI_LEVEL_SENSITIVE;
 302         polarity = ((a.value >> 8) & 0x2) ? ACPI_ACTIVE_LOW
 303                                           : ACPI_ACTIVE_HIGH;
 304         xen_events_irq = acpi_register_gsi(NULL, interrupt, trigger, polarity);
 305 #endif
 306 }
 307
 308 #ifdef CONFIG_XEN_UNPOPULATED_ALLOC
 309 /*
 310  * A type-less specific Xen resource which contains extended regions
 311  * (unused regions of guest physical address space provided by the hypervisor).
 312  */
 313 static struct resource xen_resource = {
 314         .name = "Xen unused space",
 315 };
 316
 317 int __init arch_xen_unpopulated_init(struct resource **res)
 318 {
 319         struct device_node *np;
 320         struct resource *regs, *tmp_res;
 321         uint64_t min_gpaddr = -1, max_gpaddr = 0;
 322         unsigned int i, nr_reg = 0;
 323         int rc;
 324
 325         if (!xen_domain())
 326                 return -ENODEV;
 327
 328         if (!acpi_disabled)
 329                 return -ENODEV;
 330
 331         np = of_find_compatible_node(NULL, NULL, "xen,xen");
 332         if (WARN_ON(!np))
 333                 return -ENODEV;
 334
 335         /* Skip region 0 which is reserved for grant table space */
 336         while (of_get_address(np, nr_reg + EXT_REGION_INDEX, NULL, NULL))
 337                 nr_reg++;
 338
 339         if (!nr_reg) {
 340                 pr_err("No extended regions are found\n");
 341                 of_node_put(np);
 342                 return -EINVAL;
 343         }
 344
 345         regs = kcalloc(nr_reg, sizeof(*regs), GFP_KERNEL);
 346         if (!regs) {
 347                 of_node_put(np);
 348                 return -ENOMEM;
 349         }
 350
 351         /*
 352          * Create resource from extended regions provided by the hypervisor to be
 353          * used as unused address space for Xen scratch pages.
 354          */
 355         for (i = 0; i < nr_reg; i++) {
 356                 rc = of_address_to_resource(np, i + EXT_REGION_INDEX, &regs[i]);
 357                 if (rc)
 358                         goto err;
 359
 360                 if (max_gpaddr < regs[i].end)
 361                         max_gpaddr = regs[i].end;
 362                 if (min_gpaddr > regs[i].start)
 363                         min_gpaddr = regs[i].start;
 364         }
 365
 366         xen_resource.start = min_gpaddr;
 367         xen_resource.end = max_gpaddr;
 368
 369         /*
 370          * Mark holes between extended regions as unavailable. The rest of that
 371          * address space will be available for the allocation.
 372          */
 373         for (i = 1; i < nr_reg; i++) {
 374                 resource_size_t start, end;
 375
 376                 /* There is an overlap between regions */
 377                 if (regs[i - 1].end + 1 > regs[i].start) {
 378                         rc = -EINVAL;
 379                         goto err;
 380                 }
 381
 382                 /* There is no hole between regions */
 383                 if (regs[i - 1].end + 1 == regs[i].start)
 384                         continue;
 385
 386                 start = regs[i - 1].end + 1;
 387                 end = regs[i].start - 1;
 388
 389                 tmp_res = kzalloc(sizeof(*tmp_res), GFP_KERNEL);
 390                 if (!tmp_res) {
 391                         rc = -ENOMEM;
 392                         goto err;
 393                 }
 394
 395                 tmp_res->name = "Unavailable space";
 396                 tmp_res->start = start;
 397                 tmp_res->end = end;
 398
 399                 rc = insert_resource(&xen_resource, tmp_res);
 400                 if (rc) {
 401                         pr_err("Cannot insert resource %pR (%d)\n", tmp_res, rc);
 402                         kfree(tmp_res);
 403                         goto err;
 404                 }
 405         }
 406
 407         *res = &xen_resource;
 408
 409 err:
 410         of_node_put(np);
 411         kfree(regs);
 412         return rc;
 413 }
 414 #endif
 415
 416 static void __init xen_dt_guest_init(void)
 417 {
 418         struct device_node *xen_node;
 419         struct resource res;
 420
 421         xen_node = of_find_compatible_node(NULL, NULL, "xen,xen");
 422         if (!xen_node) {
 423                 pr_err("Xen support was detected before, but it has disappeared\n");
 424                 return;
 425         }
 426
 427         xen_events_irq = irq_of_parse_and_map(xen_node, 0);
 428
 429         if (of_address_to_resource(xen_node, GRANT_TABLE_INDEX, &res)) {
 430                 pr_err("Xen grant table region is not found\n");
 431                 of_node_put(xen_node);
 432                 return;
 433         }
 434         of_node_put(xen_node);
 435         xen_grant_frames = res.start;
 436 }
 437
 438 static int __init xen_guest_init(void)
 439 {
 440         struct xen_add_to_physmap xatp;
 441         struct shared_info *shared_info_page = NULL;
 442         int rc, cpu;
 443
 444         if (!xen_domain())
 445                 return 0;
 446
 447         if (IS_ENABLED(CONFIG_XEN_VIRTIO))
 448                 virtio_set_mem_acc_cb(xen_virtio_restricted_mem_acc);
 449
 450         if (!acpi_disabled)
 451                 xen_acpi_guest_init();
 452         else
 453                 xen_dt_guest_init();
 454
 455         if (!xen_events_irq) {
 456                 pr_err("Xen event channel interrupt not found\n");
 457                 return -ENODEV;
 458         }
 459
 460         /*
 461          * The fdt parsing codes have set EFI_RUNTIME_SERVICES if Xen EFI
 462          * parameters are found. Force enable runtime services.
 463          */
 464         if (efi_enabled(EFI_RUNTIME_SERVICES))
 465                 xen_efi_runtime_setup();
 466
 467         shared_info_page = (struct shared_info *)get_zeroed_page(GFP_KERNEL);
 468
 469         if (!shared_info_page) {
 470                 pr_err("not enough memory\n");
 471                 return -ENOMEM;
 472         }
 473         xatp.domid = DOMID_SELF;
 474         xatp.idx = 0;
 475         xatp.space = XENMAPSPACE_shared_info;
 476         xatp.gpfn = virt_to_gfn(shared_info_page);
 477         if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
 478                 BUG();
 479
 480         HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
 481
 482         /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
 483          * page, we use it in the event channel upcall and in some pvclock
 484          * related functions.
 485          * The shared info contains exactly 1 CPU (the boot CPU). The guest
 486          * is required to use VCPUOP_register_vcpu_info to place vcpu info
 487          * for secondary CPUs as they are brought up.
 488          * For uniformity we use VCPUOP_register_vcpu_info even on cpu0.
 489          */
 490         xen_vcpu_info = alloc_percpu(struct vcpu_info);
 491         if (xen_vcpu_info == NULL)
 492                 return -ENOMEM;
 493
 494         /* Direct vCPU id mapping for ARM guests. */
 495         for_each_possible_cpu(cpu)
 496                 per_cpu(xen_vcpu_id, cpu) = cpu;
 497
 498         if (!xen_grant_frames) {
 499                 xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();
 500                 rc = xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
 501                                                                                    &xen_auto_xlat_grant_frames.vaddr,
 502                                                                                    xen_auto_xlat_grant_frames.count);
 503         } else
 504                 rc = gnttab_setup_auto_xlat_frames(xen_grant_frames);
 505         if (rc) {
 506                 free_percpu(xen_vcpu_info);
 507                 return rc;
 508         }
 509         gnttab_init();
 510
 511         /*
 512          * Making sure board specific code will not set up ops for
 513          * cpu idle and cpu freq.
 514          */
 515         disable_cpuidle();
 516         disable_cpufreq();
 517
 518         xen_init_IRQ();
 519
 520         if (request_percpu_irq(xen_events_irq, xen_arm_callback,
 521                                "events", &xen_vcpu)) {
 522                 pr_err("Error request IRQ %d\n", xen_events_irq);
 523                 return -EINVAL;
 524         }
 525
 526         if (!xen_kernel_unmapped_at_usr())
 527                 xen_time_setup_guest();
 528
 529         if (xen_initial_domain())
 530                 pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
 531
 532         return cpuhp_setup_state(CPUHP_AP_ARM_XEN_STARTING,
 533                                  "arm/xen:starting", xen_starting_cpu,
 534                                  xen_dying_cpu);
 535 }
 536 early_initcall(xen_guest_init);
 537
 538 static int __init xen_pm_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         return 0;
 552 }
 553 late_initcall(xen_pm_init);
 554
 555
 556 /* empty stubs */
 557 void xen_arch_pre_suspend(void) { }
 558 void xen_arch_post_suspend(int suspend_cancelled) { }
 559 void xen_timer_resume(void) { }
 560 void xen_arch_resume(void) { }
 561 void xen_arch_suspend(void) { }
 562
 563
 564 /* In the hypercall.S file. */
 565 EXPORT_SYMBOL_GPL(HYPERVISOR_event_channel_op);
 566 EXPORT_SYMBOL_GPL(HYPERVISOR_grant_table_op);
 567 EXPORT_SYMBOL_GPL(HYPERVISOR_xen_version);
 568 EXPORT_SYMBOL_GPL(HYPERVISOR_console_io);
 569 EXPORT_SYMBOL_GPL(HYPERVISOR_sched_op);
 570 EXPORT_SYMBOL_GPL(HYPERVISOR_hvm_op);
 571 EXPORT_SYMBOL_GPL(HYPERVISOR_memory_op);
 572 EXPORT_SYMBOL_GPL(HYPERVISOR_physdev_op);
 573 EXPORT_SYMBOL_GPL(HYPERVISOR_vcpu_op);
 574 EXPORT_SYMBOL_GPL(HYPERVISOR_platform_op_raw);
 575 EXPORT_SYMBOL_GPL(HYPERVISOR_multicall);
 576 EXPORT_SYMBOL_GPL(HYPERVISOR_vm_assist);
 577 EXPORT_SYMBOL_GPL(HYPERVISOR_dm_op);
 578 EXPORT_SYMBOL_GPL(privcmd_call);