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/time64.h>
  33 #include <linux/timekeeping.h>
  34 #include <linux/timekeeper_internal.h>
  35 #include <linux/acpi.h>
  36
  37 #include <linux/mm.h>
  38
  39 static struct start_info _xen_start_info;
  40 struct start_info *xen_start_info = &_xen_start_info;
  41 EXPORT_SYMBOL(xen_start_info);
  42
  43 enum xen_domain_type xen_domain_type = XEN_NATIVE;
  44 EXPORT_SYMBOL(xen_domain_type);
  45
  46 struct shared_info xen_dummy_shared_info;
  47 struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
  48
  49 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
  50 static struct vcpu_info __percpu *xen_vcpu_info;
  51
  52 /* Linux <-> Xen vCPU id mapping */
  53 DEFINE_PER_CPU(uint32_t, xen_vcpu_id);
  54 EXPORT_PER_CPU_SYMBOL(xen_vcpu_id);
  55
  56 /* These are unused until we support booting "pre-ballooned" */
  57 unsigned long xen_released_pages;
  58 struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
  59
  60 static __read_mostly unsigned int xen_events_irq;
  61
  62 uint32_t xen_start_flags;
  63 EXPORT_SYMBOL(xen_start_flags);
  64
  65 int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
  66                                int nr, struct page **pages)
  67 {
  68         return xen_xlate_unmap_gfn_range(vma, nr, pages);
  69 }
  70 EXPORT_SYMBOL_GPL(xen_unmap_domain_gfn_range);
  71
  72 static void xen_read_wallclock(struct timespec64 *ts)
  73 {
  74         u32 version;
  75         struct timespec64 now, ts_monotonic;
  76         struct shared_info *s = HYPERVISOR_shared_info;
  77         struct pvclock_wall_clock *wall_clock = &(s->wc);
  78
  79         /* get wallclock at system boot */
  80         do {
  81                 version = wall_clock->version;
  82                 rmb();          /* fetch version before time */
  83                 now.tv_sec  = ((uint64_t)wall_clock->sec_hi << 32) | wall_clock->sec;
  84                 now.tv_nsec = wall_clock->nsec;
  85                 rmb();          /* fetch time before checking version */
  86         } while ((wall_clock->version & 1) || (version != wall_clock->version));
  87
  88         /* time since system boot */
  89         ktime_get_ts64(&ts_monotonic);
  90         *ts = timespec64_add(now, ts_monotonic);
  91 }
  92
  93 static int xen_pvclock_gtod_notify(struct notifier_block *nb,
  94                                    unsigned long was_set, void *priv)
  95 {
  96         /* Protected by the calling core code serialization */
  97         static struct timespec64 next_sync;
  98
  99         struct xen_platform_op op;
 100         struct timespec64 now, system_time;
 101         struct timekeeper *tk = priv;
 102
 103         now.tv_sec = tk->xtime_sec;
 104         now.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
 105         system_time = timespec64_add(now, tk->wall_to_monotonic);
 106
 107         /*
 108          * We only take the expensive HV call when the clock was set
 109          * or when the 11 minutes RTC synchronization time elapsed.
 110          */
 111         if (!was_set && timespec64_compare(&now, &next_sync) < 0)
 112                 return NOTIFY_OK;
 113
 114         op.cmd = XENPF_settime64;
 115         op.u.settime64.mbz = 0;
 116         op.u.settime64.secs = now.tv_sec;
 117         op.u.settime64.nsecs = now.tv_nsec;
 118         op.u.settime64.system_time = timespec64_to_ns(&system_time);
 119         (void)HYPERVISOR_platform_op(&op);
 120
 121         /*
 122          * Move the next drift compensation time 11 minutes
 123          * ahead. That's emulating the sync_cmos_clock() update for
 124          * the hardware RTC.
 125          */
 126         next_sync = now;
 127         next_sync.tv_sec += 11 * 60;
 128
 129         return NOTIFY_OK;
 130 }
 131
 132 static struct notifier_block xen_pvclock_gtod_notifier = {
 133         .notifier_call = xen_pvclock_gtod_notify,
 134 };
 135
 136 static int xen_starting_cpu(unsigned int cpu)
 137 {
 138         struct vcpu_register_vcpu_info info;
 139         struct vcpu_info *vcpup;
 140         int err;
 141
 142         /*
 143          * VCPUOP_register_vcpu_info cannot be called twice for the same
 144          * vcpu, so if vcpu_info is already registered, just get out. This
 145          * can happen with cpu-hotplug.
 146          */
 147         if (per_cpu(xen_vcpu, cpu) != NULL)
 148                 goto after_register_vcpu_info;
 149
 150         pr_info("Xen: initializing cpu%d\n", cpu);
 151         vcpup = per_cpu_ptr(xen_vcpu_info, cpu);
 152
 153         info.mfn = percpu_to_gfn(vcpup);
 154         info.offset = xen_offset_in_page(vcpup);
 155
 156         err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, xen_vcpu_nr(cpu),
 157                                  &info);
 158         BUG_ON(err);
 159         per_cpu(xen_vcpu, cpu) = vcpup;
 160
 161 after_register_vcpu_info:
 162         enable_percpu_irq(xen_events_irq, 0);
 163         return 0;
 164 }
 165
 166 static int xen_dying_cpu(unsigned int cpu)
 167 {
 168         disable_percpu_irq(xen_events_irq);
 169         return 0;
 170 }
 171
 172 void xen_reboot(int reason)
 173 {
 174         struct sched_shutdown r = { .reason = reason };
 175         int rc;
 176
 177         rc = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
 178         BUG_ON(rc);
 179 }
 180
 181 static void xen_restart(enum reboot_mode reboot_mode, const char *cmd)
 182 {
 183         xen_reboot(SHUTDOWN_reboot);
 184 }
 185
 186
 187 static void xen_power_off(void)
 188 {
 189         xen_reboot(SHUTDOWN_poweroff);
 190 }
 191
 192 static irqreturn_t xen_arm_callback(int irq, void *arg)
 193 {
 194         xen_hvm_evtchn_do_upcall();
 195         return IRQ_HANDLED;
 196 }
 197
 198 static __initdata struct {
 199         const char *compat;
 200         const char *prefix;
 201         const char *version;
 202         bool found;
 203 } hyper_node = {"xen,xen", "xen,xen-", NULL, false};
 204
 205 static int __init fdt_find_hyper_node(unsigned long node, const char *uname,
 206                                       int depth, void *data)
 207 {
 208         const void *s = NULL;
 209         int len;
 210
 211         if (depth != 1 || strcmp(uname, "hypervisor") != 0)
 212                 return 0;
 213
 214         if (of_flat_dt_is_compatible(node, hyper_node.compat))
 215                 hyper_node.found = true;
 216
 217         s = of_get_flat_dt_prop(node, "compatible", &len);
 218         if (strlen(hyper_node.prefix) + 3  < len &&
 219             !strncmp(hyper_node.prefix, s, strlen(hyper_node.prefix)))
 220                 hyper_node.version = s + strlen(hyper_node.prefix);
 221
 222         /*
 223          * Check if Xen supports EFI by checking whether there is the
 224          * "/hypervisor/uefi" node in DT. If so, runtime services are available
 225          * through proxy functions (e.g. in case of Xen dom0 EFI implementation
 226          * they call special hypercall which executes relevant EFI functions)
 227          * and that is why they are always enabled.
 228          */
 229         if (IS_ENABLED(CONFIG_XEN_EFI)) {
 230                 if ((of_get_flat_dt_subnode_by_name(node, "uefi") > 0) &&
 231                     !efi_runtime_disabled())
 232                         set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
 233         }
 234
 235         return 0;
 236 }
 237
 238 /*
 239  * see Documentation/devicetree/bindings/arm/xen.txt for the
 240  * documentation of the Xen Device Tree format.
 241  */
 242 void __init xen_early_init(void)
 243 {
 244         of_scan_flat_dt(fdt_find_hyper_node, NULL);
 245         if (!hyper_node.found) {
 246                 pr_debug("No Xen support\n");
 247                 return;
 248         }
 249
 250         if (hyper_node.version == NULL) {
 251                 pr_debug("Xen version not found\n");
 252                 return;
 253         }
 254
 255         pr_info("Xen %s support found\n", hyper_node.version);
 256
 257         xen_domain_type = XEN_HVM_DOMAIN;
 258
 259         xen_setup_features();
 260
 261         if (xen_feature(XENFEAT_dom0))
 262                 xen_start_flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
 263
 264         if (!console_set_on_cmdline && !xen_initial_domain())
 265                 add_preferred_console("hvc", 0, NULL);
 266 }
 267
 268 static void __init xen_acpi_guest_init(void)
 269 {
 270 #ifdef CONFIG_ACPI
 271         struct xen_hvm_param a;
 272         int interrupt, trigger, polarity;
 273
 274         a.domid = DOMID_SELF;
 275         a.index = HVM_PARAM_CALLBACK_IRQ;
 276
 277         if (HYPERVISOR_hvm_op(HVMOP_get_param, &a)
 278             || (a.value >> 56) != HVM_PARAM_CALLBACK_TYPE_PPI) {
 279                 xen_events_irq = 0;
 280                 return;
 281         }
 282
 283         interrupt = a.value & 0xff;
 284         trigger = ((a.value >> 8) & 0x1) ? ACPI_EDGE_SENSITIVE
 285                                          : ACPI_LEVEL_SENSITIVE;
 286         polarity = ((a.value >> 8) & 0x2) ? ACPI_ACTIVE_LOW
 287                                           : ACPI_ACTIVE_HIGH;
 288         xen_events_irq = acpi_register_gsi(NULL, interrupt, trigger, polarity);
 289 #endif
 290 }
 291
 292 static void __init xen_dt_guest_init(void)
 293 {
 294         struct device_node *xen_node;
 295
 296         xen_node = of_find_compatible_node(NULL, NULL, "xen,xen");
 297         if (!xen_node) {
 298                 pr_err("Xen support was detected before, but it has disappeared\n");
 299                 return;
 300         }
 301
 302         xen_events_irq = irq_of_parse_and_map(xen_node, 0);
 303 }
 304
 305 static int __init xen_guest_init(void)
 306 {
 307         struct xen_add_to_physmap xatp;
 308         struct shared_info *shared_info_page = NULL;
 309         int cpu;
 310
 311         if (!xen_domain())
 312                 return 0;
 313
 314         if (!acpi_disabled)
 315                 xen_acpi_guest_init();
 316         else
 317                 xen_dt_guest_init();
 318
 319         if (!xen_events_irq) {
 320                 pr_err("Xen event channel interrupt not found\n");
 321                 return -ENODEV;
 322         }
 323
 324         /*
 325          * The fdt parsing codes have set EFI_RUNTIME_SERVICES if Xen EFI
 326          * parameters are found. Force enable runtime services.
 327          */
 328         if (efi_enabled(EFI_RUNTIME_SERVICES))
 329                 xen_efi_runtime_setup();
 330
 331         shared_info_page = (struct shared_info *)get_zeroed_page(GFP_KERNEL);
 332
 333         if (!shared_info_page) {
 334                 pr_err("not enough memory\n");
 335                 return -ENOMEM;
 336         }
 337         xatp.domid = DOMID_SELF;
 338         xatp.idx = 0;
 339         xatp.space = XENMAPSPACE_shared_info;
 340         xatp.gpfn = virt_to_gfn(shared_info_page);
 341         if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
 342                 BUG();
 343
 344         HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
 345
 346         /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
 347          * page, we use it in the event channel upcall and in some pvclock
 348          * related functions.
 349          * The shared info contains exactly 1 CPU (the boot CPU). The guest
 350          * is required to use VCPUOP_register_vcpu_info to place vcpu info
 351          * for secondary CPUs as they are brought up.
 352          * For uniformity we use VCPUOP_register_vcpu_info even on cpu0.
 353          */
 354         xen_vcpu_info = __alloc_percpu(sizeof(struct vcpu_info),
 355                                        1 << fls(sizeof(struct vcpu_info) - 1));
 356         if (xen_vcpu_info == NULL)
 357                 return -ENOMEM;
 358
 359         /* Direct vCPU id mapping for ARM guests. */
 360         for_each_possible_cpu(cpu)
 361                 per_cpu(xen_vcpu_id, cpu) = cpu;
 362
 363         xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();
 364         if (xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
 365                                           &xen_auto_xlat_grant_frames.vaddr,
 366                                           xen_auto_xlat_grant_frames.count)) {
 367                 free_percpu(xen_vcpu_info);
 368                 return -ENOMEM;
 369         }
 370         gnttab_init();
 371
 372         /*
 373          * Making sure board specific code will not set up ops for
 374          * cpu idle and cpu freq.
 375          */
 376         disable_cpuidle();
 377         disable_cpufreq();
 378
 379         xen_init_IRQ();
 380
 381         if (request_percpu_irq(xen_events_irq, xen_arm_callback,
 382                                "events", &xen_vcpu)) {
 383                 pr_err("Error request IRQ %d\n", xen_events_irq);
 384                 return -EINVAL;
 385         }
 386
 387         if (xen_initial_domain())
 388                 pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
 389
 390         return cpuhp_setup_state(CPUHP_AP_ARM_XEN_STARTING,
 391                                  "arm/xen:starting", xen_starting_cpu,
 392                                  xen_dying_cpu);
 393 }
 394 early_initcall(xen_guest_init);
 395
 396 static int xen_starting_runstate_cpu(unsigned int cpu)
 397 {
 398         xen_setup_runstate_info(cpu);
 399         return 0;
 400 }
 401
 402 static int __init xen_late_init(void)
 403 {
 404         if (!xen_domain())
 405                 return -ENODEV;
 406
 407         pm_power_off = xen_power_off;
 408         arm_pm_restart = xen_restart;
 409         if (!xen_initial_domain()) {
 410                 struct timespec64 ts;
 411                 xen_read_wallclock(&ts);
 412                 do_settimeofday64(&ts);
 413         }
 414
 415         if (xen_kernel_unmapped_at_usr())
 416                 return 0;
 417
 418         xen_time_setup_guest();
 419
 420         return cpuhp_setup_state(CPUHP_AP_ARM_XEN_RUNSTATE_STARTING,
 421                                  "arm/xen_runstate:starting",
 422                                  xen_starting_runstate_cpu, NULL);
 423 }
 424 late_initcall(xen_late_init);
 425
 426
 427 /* empty stubs */
 428 void xen_arch_pre_suspend(void) { }
 429 void xen_arch_post_suspend(int suspend_cancelled) { }
 430 void xen_timer_resume(void) { }
 431 void xen_arch_resume(void) { }
 432 void xen_arch_suspend(void) { }
 433
 434
 435 /* In the hypercall.S file. */
 436 EXPORT_SYMBOL_GPL(HYPERVISOR_event_channel_op);
 437 EXPORT_SYMBOL_GPL(HYPERVISOR_grant_table_op);
 438 EXPORT_SYMBOL_GPL(HYPERVISOR_xen_version);
 439 EXPORT_SYMBOL_GPL(HYPERVISOR_console_io);
 440 EXPORT_SYMBOL_GPL(HYPERVISOR_sched_op);
 441 EXPORT_SYMBOL_GPL(HYPERVISOR_hvm_op);
 442 EXPORT_SYMBOL_GPL(HYPERVISOR_memory_op);
 443 EXPORT_SYMBOL_GPL(HYPERVISOR_physdev_op);
 444 EXPORT_SYMBOL_GPL(HYPERVISOR_vcpu_op);
 445 EXPORT_SYMBOL_GPL(HYPERVISOR_tmem_op);
 446 EXPORT_SYMBOL_GPL(HYPERVISOR_platform_op_raw);
 447 EXPORT_SYMBOL_GPL(HYPERVISOR_multicall);
 448 EXPORT_SYMBOL_GPL(HYPERVISOR_vm_assist);
 449 EXPORT_SYMBOL_GPL(HYPERVISOR_dm_op);
 450 EXPORT_SYMBOL_GPL(privcmd_call);