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