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/xen/xen-ops.h>
  19 #include <asm/system_misc.h>
  20 #include <asm/efi.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/irqreturn.h>
  23 #include <linux/module.h>
  24 #include <linux/of.h>
  25 #include <linux/of_fdt.h>
  26 #include <linux/of_irq.h>
  27 #include <linux/of_address.h>
  28 #include <linux/cpuidle.h>
  29 #include <linux/cpufreq.h>
  30 #include <linux/cpu.h>
  31 #include <linux/console.h>
  32 #include <linux/pvclock_gtod.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 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
  63 uint32_t xen_start_flags;
  64 EXPORT_SYMBOL(xen_start_flags);
  65
  66 int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
  67                                int nr, struct page **pages)
  68 {
  69         return xen_xlate_unmap_gfn_range(vma, nr, pages);
  70 }
  71 EXPORT_SYMBOL_GPL(xen_unmap_domain_gfn_range);
  72
  73 static void xen_read_wallclock(struct timespec64 *ts)
  74 {
  75         u32 version;
  76         struct timespec64 now, ts_monotonic;
  77         struct shared_info *s = HYPERVISOR_shared_info;
  78         struct pvclock_wall_clock *wall_clock = &(s->wc);
  79
  80         /* get wallclock at system boot */
  81         do {
  82                 version = wall_clock->version;
  83                 rmb();          /* fetch version before time */
  84                 now.tv_sec  = ((uint64_t)wall_clock->sec_hi << 32) | wall_clock->sec;
  85                 now.tv_nsec = wall_clock->nsec;
  86                 rmb();          /* fetch time before checking version */
  87         } while ((wall_clock->version & 1) || (version != wall_clock->version));
  88
  89         /* time since system boot */
  90         ktime_get_ts64(&ts_monotonic);
  91         *ts = timespec64_add(now, ts_monotonic);
  92 }
  93
  94 static int xen_pvclock_gtod_notify(struct notifier_block *nb,
  95                                    unsigned long was_set, void *priv)
  96 {
  97         /* Protected by the calling core code serialization */
  98         static struct timespec64 next_sync;
  99
 100         struct xen_platform_op op;
 101         struct timespec64 now, system_time;
 102         struct timekeeper *tk = priv;
 103
 104         now.tv_sec = tk->xtime_sec;
 105         now.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
 106         system_time = timespec64_add(now, tk->wall_to_monotonic);
 107
 108         /*
 109          * We only take the expensive HV call when the clock was set
 110          * or when the 11 minutes RTC synchronization time elapsed.
 111          */
 112         if (!was_set && timespec64_compare(&now, &next_sync) < 0)
 113                 return NOTIFY_OK;
 114
 115         op.cmd = XENPF_settime64;
 116         op.u.settime64.mbz = 0;
 117         op.u.settime64.secs = now.tv_sec;
 118         op.u.settime64.nsecs = now.tv_nsec;
 119         op.u.settime64.system_time = timespec64_to_ns(&system_time);
 120         (void)HYPERVISOR_platform_op(&op);
 121
 122         /*
 123          * Move the next drift compensation time 11 minutes
 124          * ahead. That's emulating the sync_cmos_clock() update for
 125          * the hardware RTC.
 126          */
 127         next_sync = now;
 128         next_sync.tv_sec += 11 * 60;
 129
 130         return NOTIFY_OK;
 131 }
 132
 133 static struct notifier_block xen_pvclock_gtod_notifier = {
 134         .notifier_call = xen_pvclock_gtod_notify,
 135 };
 136
 137 static int xen_starting_cpu(unsigned int cpu)
 138 {
 139         struct vcpu_register_vcpu_info info;
 140         struct vcpu_info *vcpup;
 141         int err;
 142
 143         /*
 144          * VCPUOP_register_vcpu_info cannot be called twice for the same
 145          * vcpu, so if vcpu_info is already registered, just get out. This
 146          * can happen with cpu-hotplug.
 147          */
 148         if (per_cpu(xen_vcpu, cpu) != NULL)
 149                 goto after_register_vcpu_info;
 150
 151         pr_info("Xen: initializing cpu%d\n", cpu);
 152         vcpup = per_cpu_ptr(xen_vcpu_info, cpu);
 153
 154         info.mfn = virt_to_gfn(vcpup);
 155         info.offset = xen_offset_in_page(vcpup);
 156
 157         err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, xen_vcpu_nr(cpu),
 158                                  &info);
 159         BUG_ON(err);
 160         per_cpu(xen_vcpu, cpu) = vcpup;
 161
 162         xen_setup_runstate_info(cpu);
 163
 164 after_register_vcpu_info:
 165         enable_percpu_irq(xen_events_irq, 0);
 166         return 0;
 167 }
 168
 169 static int xen_dying_cpu(unsigned int cpu)
 170 {
 171         disable_percpu_irq(xen_events_irq);
 172         return 0;
 173 }
 174
 175 void xen_reboot(int reason)
 176 {
 177         struct sched_shutdown r = { .reason = reason };
 178         int rc;
 179
 180         rc = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
 181         BUG_ON(rc);
 182 }
 183
 184 static void xen_restart(enum reboot_mode reboot_mode, const char *cmd)
 185 {
 186         xen_reboot(SHUTDOWN_reboot);
 187 }
 188
 189
 190 static void xen_power_off(void)
 191 {
 192         xen_reboot(SHUTDOWN_poweroff);
 193 }
 194
 195 static irqreturn_t xen_arm_callback(int irq, void *arg)
 196 {
 197         xen_hvm_evtchn_do_upcall();
 198         return IRQ_HANDLED;
 199 }
 200
 201 static __initdata struct {
 202         const char *compat;
 203         const char *prefix;
 204         const char *version;
 205         bool found;
 206 } hyper_node = {"xen,xen", "xen,xen-", NULL, false};
 207
 208 static int __init fdt_find_hyper_node(unsigned long node, const char *uname,
 209                                       int depth, void *data)
 210 {
 211         const void *s = NULL;
 212         int len;
 213
 214         if (depth != 1 || strcmp(uname, "hypervisor") != 0)
 215                 return 0;
 216
 217         if (of_flat_dt_is_compatible(node, hyper_node.compat))
 218                 hyper_node.found = true;
 219
 220         s = of_get_flat_dt_prop(node, "compatible", &len);
 221         if (strlen(hyper_node.prefix) + 3  < len &&
 222             !strncmp(hyper_node.prefix, s, strlen(hyper_node.prefix)))
 223                 hyper_node.version = s + strlen(hyper_node.prefix);
 224
 225         /*
 226          * Check if Xen supports EFI by checking whether there is the
 227          * "/hypervisor/uefi" node in DT. If so, runtime services are available
 228          * through proxy functions (e.g. in case of Xen dom0 EFI implementation
 229          * they call special hypercall which executes relevant EFI functions)
 230          * and that is why they are always enabled.
 231          */
 232         if (IS_ENABLED(CONFIG_XEN_EFI)) {
 233                 if ((of_get_flat_dt_subnode_by_name(node, "uefi") > 0) &&
 234                     !efi_runtime_disabled())
 235                         set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
 236         }
 237
 238         return 0;
 239 }
 240
 241 /*
 242  * see Documentation/devicetree/bindings/arm/xen.txt for the
 243  * documentation of the Xen Device Tree format.
 244  */
 245 #define GRANT_TABLE_PHYSADDR 0
 246 void __init xen_early_init(void)
 247 {
 248         of_scan_flat_dt(fdt_find_hyper_node, NULL);
 249         if (!hyper_node.found) {
 250                 pr_debug("No Xen support\n");
 251                 return;
 252         }
 253
 254         if (hyper_node.version == NULL) {
 255                 pr_debug("Xen version not found\n");
 256                 return;
 257         }
 258
 259         pr_info("Xen %s support found\n", hyper_node.version);
 260
 261         xen_domain_type = XEN_HVM_DOMAIN;
 262
 263         xen_setup_features();
 264
 265         if (xen_feature(XENFEAT_dom0))
 266                 xen_start_flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
 267
 268         if (!console_set_on_cmdline && !xen_initial_domain())
 269                 add_preferred_console("hvc", 0, NULL);
 270 }
 271
 272 static void __init xen_acpi_guest_init(void)
 273 {
 274 #ifdef CONFIG_ACPI
 275         struct xen_hvm_param a;
 276         int interrupt, trigger, polarity;
 277
 278         a.domid = DOMID_SELF;
 279         a.index = HVM_PARAM_CALLBACK_IRQ;
 280
 281         if (HYPERVISOR_hvm_op(HVMOP_get_param, &a)
 282             || (a.value >> 56) != HVM_PARAM_CALLBACK_TYPE_PPI) {
 283                 xen_events_irq = 0;
 284                 return;
 285         }
 286
 287         interrupt = a.value & 0xff;
 288         trigger = ((a.value >> 8) & 0x1) ? ACPI_EDGE_SENSITIVE
 289                                          : ACPI_LEVEL_SENSITIVE;
 290         polarity = ((a.value >> 8) & 0x2) ? ACPI_ACTIVE_LOW
 291                                           : ACPI_ACTIVE_HIGH;
 292         xen_events_irq = acpi_register_gsi(NULL, interrupt, trigger, polarity);
 293 #endif
 294 }
 295
 296 static void __init xen_dt_guest_init(void)
 297 {
 298         struct device_node *xen_node;
 299
 300         xen_node = of_find_compatible_node(NULL, NULL, "xen,xen");
 301         if (!xen_node) {
 302                 pr_err("Xen support was detected before, but it has disappeared\n");
 303                 return;
 304         }
 305
 306         xen_events_irq = irq_of_parse_and_map(xen_node, 0);
 307 }
 308
 309 static int __init xen_guest_init(void)
 310 {
 311         struct xen_add_to_physmap xatp;
 312         struct shared_info *shared_info_page = NULL;
 313         int cpu;
 314
 315         if (!xen_domain())
 316                 return 0;
 317
 318         if (!acpi_disabled)
 319                 xen_acpi_guest_init();
 320         else
 321                 xen_dt_guest_init();
 322
 323         if (!xen_events_irq) {
 324                 pr_err("Xen event channel interrupt not found\n");
 325                 return -ENODEV;
 326         }
 327
 328         /*
 329          * The fdt parsing codes have set EFI_RUNTIME_SERVICES if Xen EFI
 330          * parameters are found. Force enable runtime services.
 331          */
 332         if (efi_enabled(EFI_RUNTIME_SERVICES))
 333                 xen_efi_runtime_setup();
 334
 335         shared_info_page = (struct shared_info *)get_zeroed_page(GFP_KERNEL);
 336
 337         if (!shared_info_page) {
 338                 pr_err("not enough memory\n");
 339                 return -ENOMEM;
 340         }
 341         xatp.domid = DOMID_SELF;
 342         xatp.idx = 0;
 343         xatp.space = XENMAPSPACE_shared_info;
 344         xatp.gpfn = virt_to_gfn(shared_info_page);
 345         if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
 346                 BUG();
 347
 348         HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
 349
 350         /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
 351          * page, we use it in the event channel upcall and in some pvclock
 352          * related functions.
 353          * The shared info contains exactly 1 CPU (the boot CPU). The guest
 354          * is required to use VCPUOP_register_vcpu_info to place vcpu info
 355          * for secondary CPUs as they are brought up.
 356          * For uniformity we use VCPUOP_register_vcpu_info even on cpu0.
 357          */
 358         xen_vcpu_info = alloc_percpu(struct vcpu_info);
 359         if (xen_vcpu_info == NULL)
 360                 return -ENOMEM;
 361
 362         /* Direct vCPU id mapping for ARM guests. */
 363         for_each_possible_cpu(cpu)
 364                 per_cpu(xen_vcpu_id, cpu) = cpu;
 365
 366         xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();
 367         if (xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
 368                                           &xen_auto_xlat_grant_frames.vaddr,
 369                                           xen_auto_xlat_grant_frames.count)) {
 370                 free_percpu(xen_vcpu_info);
 371                 return -ENOMEM;
 372         }
 373         gnttab_init();
 374         if (!xen_initial_domain())
 375                 xenbus_probe(NULL);
 376
 377         /*
 378          * Making sure board specific code will not set up ops for
 379          * cpu idle and cpu freq.
 380          */
 381         disable_cpuidle();
 382         disable_cpufreq();
 383
 384         xen_init_IRQ();
 385
 386         if (request_percpu_irq(xen_events_irq, xen_arm_callback,
 387                                "events", &xen_vcpu)) {
 388                 pr_err("Error request IRQ %d\n", xen_events_irq);
 389                 return -EINVAL;
 390         }
 391
 392         xen_time_setup_guest();
 393
 394         if (xen_initial_domain())
 395                 pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
 396
 397         return cpuhp_setup_state(CPUHP_AP_ARM_XEN_STARTING,
 398                                  "arm/xen:starting", xen_starting_cpu,
 399                                  xen_dying_cpu);
 400 }
 401 early_initcall(xen_guest_init);
 402
 403 static int __init xen_pm_init(void)
 404 {
 405         if (!xen_domain())
 406                 return -ENODEV;
 407
 408         pm_power_off = xen_power_off;
 409         arm_pm_restart = xen_restart;
 410         if (!xen_initial_domain()) {
 411                 struct timespec64 ts;
 412                 xen_read_wallclock(&ts);
 413                 do_settimeofday64(&ts);
 414         }
 415
 416         return 0;
 417 }
 418 late_initcall(xen_pm_init);
 419
 420
 421 /* empty stubs */
 422 void xen_arch_pre_suspend(void) { }
 423 void xen_arch_post_suspend(int suspend_cancelled) { }
 424 void xen_timer_resume(void) { }
 425 void xen_arch_resume(void) { }
 426 void xen_arch_suspend(void) { }
 427
 428
 429 /* In the hypercall.S file. */
 430 EXPORT_SYMBOL_GPL(HYPERVISOR_event_channel_op);
 431 EXPORT_SYMBOL_GPL(HYPERVISOR_grant_table_op);
 432 EXPORT_SYMBOL_GPL(HYPERVISOR_xen_version);
 433 EXPORT_SYMBOL_GPL(HYPERVISOR_console_io);
 434 EXPORT_SYMBOL_GPL(HYPERVISOR_sched_op);
 435 EXPORT_SYMBOL_GPL(HYPERVISOR_hvm_op);
 436 EXPORT_SYMBOL_GPL(HYPERVISOR_memory_op);
 437 EXPORT_SYMBOL_GPL(HYPERVISOR_physdev_op);
 438 EXPORT_SYMBOL_GPL(HYPERVISOR_vcpu_op);
 439 EXPORT_SYMBOL_GPL(HYPERVISOR_tmem_op);
 440 EXPORT_SYMBOL_GPL(HYPERVISOR_platform_op);
 441 EXPORT_SYMBOL_GPL(HYPERVISOR_multicall);
 442 EXPORT_SYMBOL_GPL(HYPERVISOR_vm_assist);
 443 EXPORT_SYMBOL_GPL(HYPERVISOR_dm_op);
 444 EXPORT_SYMBOL_GPL(privcmd_call);