xref: /openbmc/linux/arch/arm/xen/enlighten.c (revision 54d8c1d3) 
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(sizeof(struct vcpu_info),
488 				       1 << fls(sizeof(struct vcpu_info) - 1));
489 	if (xen_vcpu_info == NULL)
490 		return -ENOMEM;
491 
492 	/* Direct vCPU id mapping for ARM guests. */
493 	for_each_possible_cpu(cpu)
494 		per_cpu(xen_vcpu_id, cpu) = cpu;
495 
496 	if (!xen_grant_frames) {
497 		xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();
498 		rc = xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
499 										   &xen_auto_xlat_grant_frames.vaddr,
500 										   xen_auto_xlat_grant_frames.count);
501 	} else
502 		rc = gnttab_setup_auto_xlat_frames(xen_grant_frames);
503 	if (rc) {
504 		free_percpu(xen_vcpu_info);
505 		return rc;
506 	}
507 	gnttab_init();
508 
509 	/*
510 	 * Making sure board specific code will not set up ops for
511 	 * cpu idle and cpu freq.
512 	 */
513 	disable_cpuidle();
514 	disable_cpufreq();
515 
516 	xen_init_IRQ();
517 
518 	if (request_percpu_irq(xen_events_irq, xen_arm_callback,
519 			       "events", &xen_vcpu)) {
520 		pr_err("Error request IRQ %d\n", xen_events_irq);
521 		return -EINVAL;
522 	}
523 
524 	if (xen_initial_domain())
525 		pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
526 
527 	return cpuhp_setup_state(CPUHP_AP_ARM_XEN_STARTING,
528 				 "arm/xen:starting", xen_starting_cpu,
529 				 xen_dying_cpu);
530 }
531 early_initcall(xen_guest_init);
532 
533 static int xen_starting_runstate_cpu(unsigned int cpu)
534 {
535 	xen_setup_runstate_info(cpu);
536 	return 0;
537 }
538 
539 static int __init xen_late_init(void)
540 {
541 	if (!xen_domain())
542 		return -ENODEV;
543 
544 	pm_power_off = xen_power_off;
545 	register_restart_handler(&xen_restart_nb);
546 	if (!xen_initial_domain()) {
547 		struct timespec64 ts;
548 		xen_read_wallclock(&ts);
549 		do_settimeofday64(&ts);
550 	}
551 
552 	if (xen_kernel_unmapped_at_usr())
553 		return 0;
554 
555 	xen_time_setup_guest();
556 
557 	return cpuhp_setup_state(CPUHP_AP_ARM_XEN_RUNSTATE_STARTING,
558 				 "arm/xen_runstate:starting",
559 				 xen_starting_runstate_cpu, NULL);
560 }
561 late_initcall(xen_late_init);
562 
563 
564 /* empty stubs */
565 void xen_arch_pre_suspend(void) { }
566 void xen_arch_post_suspend(int suspend_cancelled) { }
567 void xen_timer_resume(void) { }
568 void xen_arch_resume(void) { }
569 void xen_arch_suspend(void) { }
570 
571 
572 /* In the hypercall.S file. */
573 EXPORT_SYMBOL_GPL(HYPERVISOR_event_channel_op);
574 EXPORT_SYMBOL_GPL(HYPERVISOR_grant_table_op);
575 EXPORT_SYMBOL_GPL(HYPERVISOR_xen_version);
576 EXPORT_SYMBOL_GPL(HYPERVISOR_console_io);
577 EXPORT_SYMBOL_GPL(HYPERVISOR_sched_op);
578 EXPORT_SYMBOL_GPL(HYPERVISOR_hvm_op);
579 EXPORT_SYMBOL_GPL(HYPERVISOR_memory_op);
580 EXPORT_SYMBOL_GPL(HYPERVISOR_physdev_op);
581 EXPORT_SYMBOL_GPL(HYPERVISOR_vcpu_op);
582 EXPORT_SYMBOL_GPL(HYPERVISOR_platform_op_raw);
583 EXPORT_SYMBOL_GPL(HYPERVISOR_multicall);
584 EXPORT_SYMBOL_GPL(HYPERVISOR_vm_assist);
585 EXPORT_SYMBOL_GPL(HYPERVISOR_dm_op);
586 EXPORT_SYMBOL_GPL(privcmd_call);
587