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