1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2015, 2016 ARM Ltd.
4  */
5 
6 #include <linux/uaccess.h>
7 #include <linux/interrupt.h>
8 #include <linux/cpu.h>
9 #include <linux/kvm_host.h>
10 #include <kvm/arm_vgic.h>
11 #include <asm/kvm_emulate.h>
12 #include <asm/kvm_mmu.h>
13 #include "vgic.h"
14 
15 /*
16  * Initialization rules: there are multiple stages to the vgic
17  * initialization, both for the distributor and the CPU interfaces.  The basic
18  * idea is that even though the VGIC is not functional or not requested from
19  * user space, the critical path of the run loop can still call VGIC functions
20  * that just won't do anything, without them having to check additional
21  * initialization flags to ensure they don't look at uninitialized data
22  * structures.
23  *
24  * Distributor:
25  *
26  * - kvm_vgic_early_init(): initialization of static data that doesn't
27  *   depend on any sizing information or emulation type. No allocation
28  *   is allowed there.
29  *
30  * - vgic_init(): allocation and initialization of the generic data
31  *   structures that depend on sizing information (number of CPUs,
32  *   number of interrupts). Also initializes the vcpu specific data
33  *   structures. Can be executed lazily for GICv2.
34  *
35  * CPU Interface:
36  *
37  * - kvm_vgic_vcpu_init(): initialization of static data that
38  *   doesn't depend on any sizing information or emulation type. No
39  *   allocation is allowed there.
40  */
41 
42 /* EARLY INIT */
43 
44 /**
45  * kvm_vgic_early_init() - Initialize static VGIC VCPU data structures
46  * @kvm: The VM whose VGIC districutor should be initialized
47  *
48  * Only do initialization of static structures that don't require any
49  * allocation or sizing information from userspace.  vgic_init() called
50  * kvm_vgic_dist_init() which takes care of the rest.
51  */
kvm_vgic_early_init(struct kvm * kvm)52 void kvm_vgic_early_init(struct kvm *kvm)
53 {
54 	struct vgic_dist *dist = &kvm->arch.vgic;
55 
56 	xa_init_flags(&dist->lpi_xa, XA_FLAGS_LOCK_IRQ);
57 }
58 
59 /* CREATION */
60 
61 /**
62  * kvm_vgic_create: triggered by the instantiation of the VGIC device by
63  * user space, either through the legacy KVM_CREATE_IRQCHIP ioctl (v2 only)
64  * or through the generic KVM_CREATE_DEVICE API ioctl.
65  * irqchip_in_kernel() tells you if this function succeeded or not.
66  * @kvm: kvm struct pointer
67  * @type: KVM_DEV_TYPE_ARM_VGIC_V[23]
68  */
kvm_vgic_create(struct kvm * kvm,u32 type)69 int kvm_vgic_create(struct kvm *kvm, u32 type)
70 {
71 	struct kvm_vcpu *vcpu;
72 	unsigned long i;
73 	int ret;
74 
75 	/*
76 	 * This function is also called by the KVM_CREATE_IRQCHIP handler,
77 	 * which had no chance yet to check the availability of the GICv2
78 	 * emulation. So check this here again. KVM_CREATE_DEVICE does
79 	 * the proper checks already.
80 	 */
81 	if (type == KVM_DEV_TYPE_ARM_VGIC_V2 &&
82 		!kvm_vgic_global_state.can_emulate_gicv2)
83 		return -ENODEV;
84 
85 	/* Must be held to avoid race with vCPU creation */
86 	lockdep_assert_held(&kvm->lock);
87 
88 	ret = -EBUSY;
89 	if (!lock_all_vcpus(kvm))
90 		return ret;
91 
92 	mutex_lock(&kvm->arch.config_lock);
93 
94 	if (irqchip_in_kernel(kvm)) {
95 		ret = -EEXIST;
96 		goto out_unlock;
97 	}
98 
99 	kvm_for_each_vcpu(i, vcpu, kvm) {
100 		if (vcpu_has_run_once(vcpu))
101 			goto out_unlock;
102 	}
103 	ret = 0;
104 
105 	if (type == KVM_DEV_TYPE_ARM_VGIC_V2)
106 		kvm->max_vcpus = VGIC_V2_MAX_CPUS;
107 	else
108 		kvm->max_vcpus = VGIC_V3_MAX_CPUS;
109 
110 	if (atomic_read(&kvm->online_vcpus) > kvm->max_vcpus) {
111 		ret = -E2BIG;
112 		goto out_unlock;
113 	}
114 
115 	kvm->arch.vgic.in_kernel = true;
116 	kvm->arch.vgic.vgic_model = type;
117 
118 	kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
119 
120 	if (type == KVM_DEV_TYPE_ARM_VGIC_V2)
121 		kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
122 	else
123 		INIT_LIST_HEAD(&kvm->arch.vgic.rd_regions);
124 
125 out_unlock:
126 	mutex_unlock(&kvm->arch.config_lock);
127 	unlock_all_vcpus(kvm);
128 	return ret;
129 }
130 
131 /* INIT/DESTROY */
132 
133 /**
134  * kvm_vgic_dist_init: initialize the dist data structures
135  * @kvm: kvm struct pointer
136  * @nr_spis: number of spis, frozen by caller
137  */
kvm_vgic_dist_init(struct kvm * kvm,unsigned int nr_spis)138 static int kvm_vgic_dist_init(struct kvm *kvm, unsigned int nr_spis)
139 {
140 	struct vgic_dist *dist = &kvm->arch.vgic;
141 	struct kvm_vcpu *vcpu0 = kvm_get_vcpu(kvm, 0);
142 	int i;
143 
144 	dist->spis = kcalloc(nr_spis, sizeof(struct vgic_irq), GFP_KERNEL_ACCOUNT);
145 	if (!dist->spis)
146 		return  -ENOMEM;
147 
148 	/*
149 	 * In the following code we do not take the irq struct lock since
150 	 * no other action on irq structs can happen while the VGIC is
151 	 * not initialized yet:
152 	 * If someone wants to inject an interrupt or does a MMIO access, we
153 	 * require prior initialization in case of a virtual GICv3 or trigger
154 	 * initialization when using a virtual GICv2.
155 	 */
156 	for (i = 0; i < nr_spis; i++) {
157 		struct vgic_irq *irq = &dist->spis[i];
158 
159 		irq->intid = i + VGIC_NR_PRIVATE_IRQS;
160 		INIT_LIST_HEAD(&irq->ap_list);
161 		raw_spin_lock_init(&irq->irq_lock);
162 		irq->vcpu = NULL;
163 		irq->target_vcpu = vcpu0;
164 		kref_init(&irq->refcount);
165 		switch (dist->vgic_model) {
166 		case KVM_DEV_TYPE_ARM_VGIC_V2:
167 			irq->targets = 0;
168 			irq->group = 0;
169 			break;
170 		case KVM_DEV_TYPE_ARM_VGIC_V3:
171 			irq->mpidr = 0;
172 			irq->group = 1;
173 			break;
174 		default:
175 			kfree(dist->spis);
176 			dist->spis = NULL;
177 			return -EINVAL;
178 		}
179 	}
180 	return 0;
181 }
182 
vgic_allocate_private_irqs_locked(struct kvm_vcpu * vcpu)183 static int vgic_allocate_private_irqs_locked(struct kvm_vcpu *vcpu)
184 {
185 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
186 	int i;
187 
188 	lockdep_assert_held(&vcpu->kvm->arch.config_lock);
189 
190 	if (vgic_cpu->private_irqs)
191 		return 0;
192 
193 	vgic_cpu->private_irqs = kcalloc(VGIC_NR_PRIVATE_IRQS,
194 					 sizeof(struct vgic_irq),
195 					 GFP_KERNEL_ACCOUNT);
196 
197 	if (!vgic_cpu->private_irqs)
198 		return -ENOMEM;
199 
200 	/*
201 	 * Enable and configure all SGIs to be edge-triggered and
202 	 * configure all PPIs as level-triggered.
203 	 */
204 	for (i = 0; i < VGIC_NR_PRIVATE_IRQS; i++) {
205 		struct vgic_irq *irq = &vgic_cpu->private_irqs[i];
206 
207 		INIT_LIST_HEAD(&irq->ap_list);
208 		raw_spin_lock_init(&irq->irq_lock);
209 		irq->intid = i;
210 		irq->vcpu = NULL;
211 		irq->target_vcpu = vcpu;
212 		kref_init(&irq->refcount);
213 		if (vgic_irq_is_sgi(i)) {
214 			/* SGIs */
215 			irq->enabled = 1;
216 			irq->config = VGIC_CONFIG_EDGE;
217 		} else {
218 			/* PPIs */
219 			irq->config = VGIC_CONFIG_LEVEL;
220 		}
221 	}
222 
223 	return 0;
224 }
225 
vgic_allocate_private_irqs(struct kvm_vcpu * vcpu)226 static int vgic_allocate_private_irqs(struct kvm_vcpu *vcpu)
227 {
228 	int ret;
229 
230 	mutex_lock(&vcpu->kvm->arch.config_lock);
231 	ret = vgic_allocate_private_irqs_locked(vcpu);
232 	mutex_unlock(&vcpu->kvm->arch.config_lock);
233 
234 	return ret;
235 }
236 
237 /**
238  * kvm_vgic_vcpu_init() - Initialize static VGIC VCPU data
239  * structures and register VCPU-specific KVM iodevs
240  *
241  * @vcpu: pointer to the VCPU being created and initialized
242  *
243  * Only do initialization, but do not actually enable the
244  * VGIC CPU interface
245  */
kvm_vgic_vcpu_init(struct kvm_vcpu * vcpu)246 int kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu)
247 {
248 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
249 	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
250 	int ret = 0;
251 
252 	vgic_cpu->rd_iodev.base_addr = VGIC_ADDR_UNDEF;
253 
254 	INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
255 	raw_spin_lock_init(&vgic_cpu->ap_list_lock);
256 	atomic_set(&vgic_cpu->vgic_v3.its_vpe.vlpi_count, 0);
257 
258 	if (!irqchip_in_kernel(vcpu->kvm))
259 		return 0;
260 
261 	ret = vgic_allocate_private_irqs(vcpu);
262 	if (ret)
263 		return ret;
264 
265 	/*
266 	 * If we are creating a VCPU with a GICv3 we must also register the
267 	 * KVM io device for the redistributor that belongs to this VCPU.
268 	 */
269 	if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) {
270 		mutex_lock(&vcpu->kvm->slots_lock);
271 		ret = vgic_register_redist_iodev(vcpu);
272 		mutex_unlock(&vcpu->kvm->slots_lock);
273 	}
274 	return ret;
275 }
276 
kvm_vgic_vcpu_enable(struct kvm_vcpu * vcpu)277 static void kvm_vgic_vcpu_enable(struct kvm_vcpu *vcpu)
278 {
279 	if (kvm_vgic_global_state.type == VGIC_V2)
280 		vgic_v2_enable(vcpu);
281 	else
282 		vgic_v3_enable(vcpu);
283 }
284 
285 /*
286  * vgic_init: allocates and initializes dist and vcpu data structures
287  * depending on two dimensioning parameters:
288  * - the number of spis
289  * - the number of vcpus
290  * The function is generally called when nr_spis has been explicitly set
291  * by the guest through the KVM DEVICE API. If not nr_spis is set to 256.
292  * vgic_initialized() returns true when this function has succeeded.
293  */
vgic_init(struct kvm * kvm)294 int vgic_init(struct kvm *kvm)
295 {
296 	struct vgic_dist *dist = &kvm->arch.vgic;
297 	struct kvm_vcpu *vcpu;
298 	int ret = 0, i;
299 	unsigned long idx;
300 
301 	lockdep_assert_held(&kvm->arch.config_lock);
302 
303 	if (vgic_initialized(kvm))
304 		return 0;
305 
306 	/* Are we also in the middle of creating a VCPU? */
307 	if (kvm->created_vcpus != atomic_read(&kvm->online_vcpus))
308 		return -EBUSY;
309 
310 	/* freeze the number of spis */
311 	if (!dist->nr_spis)
312 		dist->nr_spis = VGIC_NR_IRQS_LEGACY - VGIC_NR_PRIVATE_IRQS;
313 
314 	ret = kvm_vgic_dist_init(kvm, dist->nr_spis);
315 	if (ret)
316 		goto out;
317 
318 	/* Initialize groups on CPUs created before the VGIC type was known */
319 	kvm_for_each_vcpu(idx, vcpu, kvm) {
320 		ret = vgic_allocate_private_irqs_locked(vcpu);
321 		if (ret)
322 			goto out;
323 
324 		for (i = 0; i < VGIC_NR_PRIVATE_IRQS; i++) {
325 			struct vgic_irq *irq = vgic_get_irq(kvm, vcpu, i);
326 
327 			switch (dist->vgic_model) {
328 			case KVM_DEV_TYPE_ARM_VGIC_V3:
329 				irq->group = 1;
330 				irq->mpidr = kvm_vcpu_get_mpidr_aff(vcpu);
331 				break;
332 			case KVM_DEV_TYPE_ARM_VGIC_V2:
333 				irq->group = 0;
334 				irq->targets = 1U << idx;
335 				break;
336 			default:
337 				ret = -EINVAL;
338 			}
339 
340 			vgic_put_irq(kvm, irq);
341 
342 			if (ret)
343 				goto out;
344 		}
345 	}
346 
347 	/*
348 	 * If we have GICv4.1 enabled, unconditionally request enable the
349 	 * v4 support so that we get HW-accelerated vSGIs. Otherwise, only
350 	 * enable it if we present a virtual ITS to the guest.
351 	 */
352 	if (vgic_supports_direct_msis(kvm)) {
353 		ret = vgic_v4_init(kvm);
354 		if (ret)
355 			goto out;
356 	}
357 
358 	kvm_for_each_vcpu(idx, vcpu, kvm)
359 		kvm_vgic_vcpu_enable(vcpu);
360 
361 	ret = kvm_vgic_setup_default_irq_routing(kvm);
362 	if (ret)
363 		goto out;
364 
365 	vgic_debug_init(kvm);
366 
367 	/*
368 	 * If userspace didn't set the GIC implementation revision,
369 	 * default to the latest and greatest. You know want it.
370 	 */
371 	if (!dist->implementation_rev)
372 		dist->implementation_rev = KVM_VGIC_IMP_REV_LATEST;
373 	dist->initialized = true;
374 
375 out:
376 	return ret;
377 }
378 
kvm_vgic_dist_destroy(struct kvm * kvm)379 static void kvm_vgic_dist_destroy(struct kvm *kvm)
380 {
381 	struct vgic_dist *dist = &kvm->arch.vgic;
382 	struct vgic_redist_region *rdreg, *next;
383 
384 	dist->ready = false;
385 	dist->initialized = false;
386 
387 	kfree(dist->spis);
388 	dist->spis = NULL;
389 	dist->nr_spis = 0;
390 	dist->vgic_dist_base = VGIC_ADDR_UNDEF;
391 
392 	if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) {
393 		list_for_each_entry_safe(rdreg, next, &dist->rd_regions, list)
394 			vgic_v3_free_redist_region(kvm, rdreg);
395 		INIT_LIST_HEAD(&dist->rd_regions);
396 	} else {
397 		dist->vgic_cpu_base = VGIC_ADDR_UNDEF;
398 	}
399 
400 	if (vgic_supports_direct_msis(kvm))
401 		vgic_v4_teardown(kvm);
402 
403 	xa_destroy(&dist->lpi_xa);
404 }
405 
__kvm_vgic_vcpu_destroy(struct kvm_vcpu * vcpu)406 static void __kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
407 {
408 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
409 
410 	/*
411 	 * Retire all pending LPIs on this vcpu anyway as we're
412 	 * going to destroy it.
413 	 */
414 	vgic_flush_pending_lpis(vcpu);
415 
416 	INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
417 	kfree(vgic_cpu->private_irqs);
418 	vgic_cpu->private_irqs = NULL;
419 
420 	if (vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) {
421 		/*
422 		 * If this vCPU is being destroyed because of a failed creation
423 		 * then unregister the redistributor to avoid leaving behind a
424 		 * dangling pointer to the vCPU struct.
425 		 *
426 		 * vCPUs that have been successfully created (i.e. added to
427 		 * kvm->vcpu_array) get unregistered in kvm_vgic_destroy(), as
428 		 * this function gets called while holding kvm->arch.config_lock
429 		 * in the VM teardown path and would otherwise introduce a lock
430 		 * inversion w.r.t. kvm->srcu.
431 		 *
432 		 * vCPUs that failed creation are torn down outside of the
433 		 * kvm->arch.config_lock and do not get unregistered in
434 		 * kvm_vgic_destroy(), meaning it is both safe and necessary to
435 		 * do so here.
436 		 */
437 		if (kvm_get_vcpu_by_id(vcpu->kvm, vcpu->vcpu_id) != vcpu)
438 			vgic_unregister_redist_iodev(vcpu);
439 
440 		vgic_cpu->rd_iodev.base_addr = VGIC_ADDR_UNDEF;
441 	}
442 }
443 
kvm_vgic_vcpu_destroy(struct kvm_vcpu * vcpu)444 void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
445 {
446 	struct kvm *kvm = vcpu->kvm;
447 
448 	mutex_lock(&kvm->slots_lock);
449 	__kvm_vgic_vcpu_destroy(vcpu);
450 	mutex_unlock(&kvm->slots_lock);
451 }
452 
kvm_vgic_destroy(struct kvm * kvm)453 void kvm_vgic_destroy(struct kvm *kvm)
454 {
455 	struct kvm_vcpu *vcpu;
456 	unsigned long i;
457 
458 	mutex_lock(&kvm->slots_lock);
459 	mutex_lock(&kvm->arch.config_lock);
460 
461 	vgic_debug_destroy(kvm);
462 
463 	kvm_for_each_vcpu(i, vcpu, kvm)
464 		__kvm_vgic_vcpu_destroy(vcpu);
465 
466 	kvm_vgic_dist_destroy(kvm);
467 
468 	mutex_unlock(&kvm->arch.config_lock);
469 
470 	if (kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3)
471 		kvm_for_each_vcpu(i, vcpu, kvm)
472 			vgic_unregister_redist_iodev(vcpu);
473 
474 	mutex_unlock(&kvm->slots_lock);
475 }
476 
477 /**
478  * vgic_lazy_init: Lazy init is only allowed if the GIC exposed to the guest
479  * is a GICv2. A GICv3 must be explicitly initialized by userspace using the
480  * KVM_DEV_ARM_VGIC_GRP_CTRL KVM_DEVICE group.
481  * @kvm: kvm struct pointer
482  */
vgic_lazy_init(struct kvm * kvm)483 int vgic_lazy_init(struct kvm *kvm)
484 {
485 	int ret = 0;
486 
487 	if (unlikely(!vgic_initialized(kvm))) {
488 		/*
489 		 * We only provide the automatic initialization of the VGIC
490 		 * for the legacy case of a GICv2. Any other type must
491 		 * be explicitly initialized once setup with the respective
492 		 * KVM device call.
493 		 */
494 		if (kvm->arch.vgic.vgic_model != KVM_DEV_TYPE_ARM_VGIC_V2)
495 			return -EBUSY;
496 
497 		mutex_lock(&kvm->arch.config_lock);
498 		ret = vgic_init(kvm);
499 		mutex_unlock(&kvm->arch.config_lock);
500 	}
501 
502 	return ret;
503 }
504 
505 /* RESOURCE MAPPING */
506 
507 /**
508  * kvm_vgic_map_resources - map the MMIO regions
509  * @kvm: kvm struct pointer
510  *
511  * Map the MMIO regions depending on the VGIC model exposed to the guest
512  * called on the first VCPU run.
513  * Also map the virtual CPU interface into the VM.
514  * v2 calls vgic_init() if not already done.
515  * v3 and derivatives return an error if the VGIC is not initialized.
516  * vgic_ready() returns true if this function has succeeded.
517  */
kvm_vgic_map_resources(struct kvm * kvm)518 int kvm_vgic_map_resources(struct kvm *kvm)
519 {
520 	struct vgic_dist *dist = &kvm->arch.vgic;
521 	enum vgic_type type;
522 	gpa_t dist_base;
523 	int ret = 0;
524 
525 	if (likely(vgic_ready(kvm)))
526 		return 0;
527 
528 	mutex_lock(&kvm->slots_lock);
529 	mutex_lock(&kvm->arch.config_lock);
530 	if (vgic_ready(kvm))
531 		goto out;
532 
533 	if (!irqchip_in_kernel(kvm))
534 		goto out;
535 
536 	if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2) {
537 		ret = vgic_v2_map_resources(kvm);
538 		type = VGIC_V2;
539 	} else {
540 		ret = vgic_v3_map_resources(kvm);
541 		type = VGIC_V3;
542 	}
543 
544 	if (ret)
545 		goto out;
546 
547 	dist_base = dist->vgic_dist_base;
548 	mutex_unlock(&kvm->arch.config_lock);
549 
550 	ret = vgic_register_dist_iodev(kvm, dist_base, type);
551 	if (ret) {
552 		kvm_err("Unable to register VGIC dist MMIO regions\n");
553 		goto out_slots;
554 	}
555 
556 	/*
557 	 * kvm_io_bus_register_dev() guarantees all readers see the new MMIO
558 	 * registration before returning through synchronize_srcu(), which also
559 	 * implies a full memory barrier. As such, marking the distributor as
560 	 * 'ready' here is guaranteed to be ordered after all vCPUs having seen
561 	 * a completely configured distributor.
562 	 */
563 	dist->ready = true;
564 	goto out_slots;
565 out:
566 	mutex_unlock(&kvm->arch.config_lock);
567 out_slots:
568 	if (ret)
569 		kvm_vm_dead(kvm);
570 
571 	mutex_unlock(&kvm->slots_lock);
572 
573 	return ret;
574 }
575 
576 /* GENERIC PROBE */
577 
kvm_vgic_cpu_up(void)578 void kvm_vgic_cpu_up(void)
579 {
580 	enable_percpu_irq(kvm_vgic_global_state.maint_irq, 0);
581 }
582 
583 
kvm_vgic_cpu_down(void)584 void kvm_vgic_cpu_down(void)
585 {
586 	disable_percpu_irq(kvm_vgic_global_state.maint_irq);
587 }
588 
vgic_maintenance_handler(int irq,void * data)589 static irqreturn_t vgic_maintenance_handler(int irq, void *data)
590 {
591 	/*
592 	 * We cannot rely on the vgic maintenance interrupt to be
593 	 * delivered synchronously. This means we can only use it to
594 	 * exit the VM, and we perform the handling of EOIed
595 	 * interrupts on the exit path (see vgic_fold_lr_state).
596 	 */
597 	return IRQ_HANDLED;
598 }
599 
600 static struct gic_kvm_info *gic_kvm_info;
601 
vgic_set_kvm_info(const struct gic_kvm_info * info)602 void __init vgic_set_kvm_info(const struct gic_kvm_info *info)
603 {
604 	BUG_ON(gic_kvm_info != NULL);
605 	gic_kvm_info = kmalloc(sizeof(*info), GFP_KERNEL);
606 	if (gic_kvm_info)
607 		*gic_kvm_info = *info;
608 }
609 
610 /**
611  * kvm_vgic_init_cpu_hardware - initialize the GIC VE hardware
612  *
613  * For a specific CPU, initialize the GIC VE hardware.
614  */
kvm_vgic_init_cpu_hardware(void)615 void kvm_vgic_init_cpu_hardware(void)
616 {
617 	BUG_ON(preemptible());
618 
619 	/*
620 	 * We want to make sure the list registers start out clear so that we
621 	 * only have the program the used registers.
622 	 */
623 	if (kvm_vgic_global_state.type == VGIC_V2)
624 		vgic_v2_init_lrs();
625 	else
626 		kvm_call_hyp(__vgic_v3_init_lrs);
627 }
628 
629 /**
630  * kvm_vgic_hyp_init: populates the kvm_vgic_global_state variable
631  * according to the host GIC model. Accordingly calls either
632  * vgic_v2/v3_probe which registers the KVM_DEVICE that can be
633  * instantiated by a guest later on .
634  */
kvm_vgic_hyp_init(void)635 int kvm_vgic_hyp_init(void)
636 {
637 	bool has_mask;
638 	int ret;
639 
640 	if (!gic_kvm_info)
641 		return -ENODEV;
642 
643 	has_mask = !gic_kvm_info->no_maint_irq_mask;
644 
645 	if (has_mask && !gic_kvm_info->maint_irq) {
646 		kvm_err("No vgic maintenance irq\n");
647 		return -ENXIO;
648 	}
649 
650 	/*
651 	 * If we get one of these oddball non-GICs, taint the kernel,
652 	 * as we have no idea of how they *really* behave.
653 	 */
654 	if (gic_kvm_info->no_hw_deactivation) {
655 		kvm_info("Non-architectural vgic, tainting kernel\n");
656 		add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK);
657 		kvm_vgic_global_state.no_hw_deactivation = true;
658 	}
659 
660 	switch (gic_kvm_info->type) {
661 	case GIC_V2:
662 		ret = vgic_v2_probe(gic_kvm_info);
663 		break;
664 	case GIC_V3:
665 		ret = vgic_v3_probe(gic_kvm_info);
666 		if (!ret) {
667 			static_branch_enable(&kvm_vgic_global_state.gicv3_cpuif);
668 			kvm_info("GIC system register CPU interface enabled\n");
669 		}
670 		break;
671 	default:
672 		ret = -ENODEV;
673 	}
674 
675 	kvm_vgic_global_state.maint_irq = gic_kvm_info->maint_irq;
676 
677 	kfree(gic_kvm_info);
678 	gic_kvm_info = NULL;
679 
680 	if (ret)
681 		return ret;
682 
683 	if (!has_mask && !kvm_vgic_global_state.maint_irq)
684 		return 0;
685 
686 	ret = request_percpu_irq(kvm_vgic_global_state.maint_irq,
687 				 vgic_maintenance_handler,
688 				 "vgic", kvm_get_running_vcpus());
689 	if (ret) {
690 		kvm_err("Cannot register interrupt %d\n",
691 			kvm_vgic_global_state.maint_irq);
692 		return ret;
693 	}
694 
695 	kvm_info("vgic interrupt IRQ%d\n", kvm_vgic_global_state.maint_irq);
696 	return 0;
697 }
698