xref: /linux/arch/arm64/kvm/vgic/vgic-init.c (revision 4ea7c1717f3f2344f7a1cdab4f5875cfa89c87a9)
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 doesn't depend
38  *   on any sizing information. Private interrupts are allocated if not
39  *   already allocated at vgic-creation time.
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 static int vgic_allocate_private_irqs_locked(struct kvm_vcpu *vcpu, u32 type);
62 
63 /**
64  * kvm_vgic_create: triggered by the instantiation of the VGIC device by
65  * user space, either through the legacy KVM_CREATE_IRQCHIP ioctl (v2 only)
66  * or through the generic KVM_CREATE_DEVICE API ioctl.
67  * irqchip_in_kernel() tells you if this function succeeded or not.
68  * @kvm: kvm struct pointer
69  * @type: KVM_DEV_TYPE_ARM_VGIC_V[23]
70  */
kvm_vgic_create(struct kvm * kvm,u32 type)71 int kvm_vgic_create(struct kvm *kvm, u32 type)
72 {
73 	struct kvm_vcpu *vcpu;
74 	u64 aa64pfr0, pfr1;
75 	unsigned long i;
76 	int ret;
77 
78 	/*
79 	 * This function is also called by the KVM_CREATE_IRQCHIP handler,
80 	 * which had no chance yet to check the availability of the GICv2
81 	 * emulation. So check this here again. KVM_CREATE_DEVICE does
82 	 * the proper checks already.
83 	 */
84 	if (type == KVM_DEV_TYPE_ARM_VGIC_V2 &&
85 		!kvm_vgic_global_state.can_emulate_gicv2)
86 		return -ENODEV;
87 
88 	/*
89 	 * Ensure mutual exclusion with vCPU creation and any vCPU ioctls by:
90 	 *
91 	 *  - Holding kvm->lock to prevent KVM_CREATE_VCPU from reaching
92 	 *    kvm_arch_vcpu_precreate() and ensuring created_vcpus is stable.
93 	 *    This alone is insufficient, as kvm_vm_ioctl_create_vcpu() drops
94 	 *    the kvm->lock before completing the vCPU creation.
95 	 */
96 	lockdep_assert_held(&kvm->lock);
97 
98 	/*
99 	 *  - Acquiring the vCPU mutex for every *online* vCPU to prevent
100 	 *    concurrent vCPU ioctls for vCPUs already visible to userspace.
101 	 */
102 	ret = -EBUSY;
103 	if (kvm_trylock_all_vcpus(kvm))
104 		return ret;
105 
106 	/*
107 	 *  - Taking the config_lock which protects VGIC data structures such
108 	 *    as the per-vCPU arrays of private IRQs (SGIs, PPIs).
109 	 */
110 	mutex_lock(&kvm->arch.config_lock);
111 
112 	/*
113 	 * - Bailing on the entire thing if a vCPU is in the middle of creation,
114 	 *   dropped the kvm->lock, but hasn't reached kvm_arch_vcpu_create().
115 	 *
116 	 * The whole combination of this guarantees that no vCPU can get into
117 	 * KVM with a VGIC configuration inconsistent with the VM's VGIC.
118 	 */
119 	if (kvm->created_vcpus != atomic_read(&kvm->online_vcpus))
120 		goto out_unlock;
121 
122 	if (irqchip_in_kernel(kvm)) {
123 		ret = -EEXIST;
124 		goto out_unlock;
125 	}
126 
127 	kvm_for_each_vcpu(i, vcpu, kvm) {
128 		if (vcpu_has_run_once(vcpu))
129 			goto out_unlock;
130 	}
131 	ret = 0;
132 
133 	if (type == KVM_DEV_TYPE_ARM_VGIC_V2)
134 		kvm->max_vcpus = VGIC_V2_MAX_CPUS;
135 	else
136 		kvm->max_vcpus = VGIC_V3_MAX_CPUS;
137 
138 	if (atomic_read(&kvm->online_vcpus) > kvm->max_vcpus) {
139 		ret = -E2BIG;
140 		goto out_unlock;
141 	}
142 
143 	kvm_for_each_vcpu(i, vcpu, kvm) {
144 		ret = vgic_allocate_private_irqs_locked(vcpu, type);
145 		if (ret)
146 			break;
147 	}
148 
149 	if (ret) {
150 		kvm_for_each_vcpu(i, vcpu, kvm) {
151 			struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
152 			kfree(vgic_cpu->private_irqs);
153 			vgic_cpu->private_irqs = NULL;
154 		}
155 
156 		goto out_unlock;
157 	}
158 
159 	kvm->arch.vgic.in_kernel = true;
160 	kvm->arch.vgic.vgic_model = type;
161 	kvm->arch.vgic.implementation_rev = KVM_VGIC_IMP_REV_LATEST;
162 
163 	kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
164 
165 	aa64pfr0 = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1) & ~ID_AA64PFR0_EL1_GIC;
166 	pfr1 = kvm_read_vm_id_reg(kvm, SYS_ID_PFR1_EL1) & ~ID_PFR1_EL1_GIC;
167 
168 	if (type == KVM_DEV_TYPE_ARM_VGIC_V2) {
169 		kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
170 	} else {
171 		INIT_LIST_HEAD(&kvm->arch.vgic.rd_regions);
172 		aa64pfr0 |= SYS_FIELD_PREP_ENUM(ID_AA64PFR0_EL1, GIC, IMP);
173 		pfr1 |= SYS_FIELD_PREP_ENUM(ID_PFR1_EL1, GIC, GICv3);
174 	}
175 
176 	kvm_set_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1, aa64pfr0);
177 	kvm_set_vm_id_reg(kvm, SYS_ID_PFR1_EL1, pfr1);
178 
179 	if (type == KVM_DEV_TYPE_ARM_VGIC_V3)
180 		kvm->arch.vgic.nassgicap = system_supports_direct_sgis();
181 
182 out_unlock:
183 	mutex_unlock(&kvm->arch.config_lock);
184 	kvm_unlock_all_vcpus(kvm);
185 	return ret;
186 }
187 
188 /* INIT/DESTROY */
189 
190 /**
191  * kvm_vgic_dist_init: initialize the dist data structures
192  * @kvm: kvm struct pointer
193  * @nr_spis: number of spis, frozen by caller
194  */
kvm_vgic_dist_init(struct kvm * kvm,unsigned int nr_spis)195 static int kvm_vgic_dist_init(struct kvm *kvm, unsigned int nr_spis)
196 {
197 	struct vgic_dist *dist = &kvm->arch.vgic;
198 	struct kvm_vcpu *vcpu0 = kvm_get_vcpu(kvm, 0);
199 	int i;
200 
201 	dist->spis = kcalloc(nr_spis, sizeof(struct vgic_irq), GFP_KERNEL_ACCOUNT);
202 	if (!dist->spis)
203 		return  -ENOMEM;
204 
205 	/*
206 	 * In the following code we do not take the irq struct lock since
207 	 * no other action on irq structs can happen while the VGIC is
208 	 * not initialized yet:
209 	 * If someone wants to inject an interrupt or does a MMIO access, we
210 	 * require prior initialization in case of a virtual GICv3 or trigger
211 	 * initialization when using a virtual GICv2.
212 	 */
213 	for (i = 0; i < nr_spis; i++) {
214 		struct vgic_irq *irq = &dist->spis[i];
215 
216 		irq->intid = i + VGIC_NR_PRIVATE_IRQS;
217 		INIT_LIST_HEAD(&irq->ap_list);
218 		raw_spin_lock_init(&irq->irq_lock);
219 		irq->vcpu = NULL;
220 		irq->target_vcpu = vcpu0;
221 		refcount_set(&irq->refcount, 0);
222 		switch (dist->vgic_model) {
223 		case KVM_DEV_TYPE_ARM_VGIC_V2:
224 			irq->targets = 0;
225 			irq->group = 0;
226 			break;
227 		case KVM_DEV_TYPE_ARM_VGIC_V3:
228 			irq->mpidr = 0;
229 			irq->group = 1;
230 			break;
231 		default:
232 			kfree(dist->spis);
233 			dist->spis = NULL;
234 			return -EINVAL;
235 		}
236 	}
237 	return 0;
238 }
239 
240 /* Default GICv3 Maintenance Interrupt INTID, as per SBSA */
241 #define DEFAULT_MI_INTID	25
242 
kvm_vgic_vcpu_nv_init(struct kvm_vcpu * vcpu)243 int kvm_vgic_vcpu_nv_init(struct kvm_vcpu *vcpu)
244 {
245 	int ret;
246 
247 	guard(mutex)(&vcpu->kvm->arch.config_lock);
248 
249 	/*
250 	 * Matching the tradition established with the timers, provide
251 	 * a default PPI for the maintenance interrupt. It makes
252 	 * things easier to reason about.
253 	 */
254 	if (vcpu->kvm->arch.vgic.mi_intid == 0)
255 		vcpu->kvm->arch.vgic.mi_intid = DEFAULT_MI_INTID;
256 	ret = kvm_vgic_set_owner(vcpu, vcpu->kvm->arch.vgic.mi_intid, vcpu);
257 
258 	return ret;
259 }
260 
vgic_allocate_private_irqs_locked(struct kvm_vcpu * vcpu,u32 type)261 static int vgic_allocate_private_irqs_locked(struct kvm_vcpu *vcpu, u32 type)
262 {
263 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
264 	int i;
265 
266 	lockdep_assert_held(&vcpu->kvm->arch.config_lock);
267 
268 	if (vgic_cpu->private_irqs)
269 		return 0;
270 
271 	vgic_cpu->private_irqs = kcalloc(VGIC_NR_PRIVATE_IRQS,
272 					 sizeof(struct vgic_irq),
273 					 GFP_KERNEL_ACCOUNT);
274 
275 	if (!vgic_cpu->private_irqs)
276 		return -ENOMEM;
277 
278 	/*
279 	 * Enable and configure all SGIs to be edge-triggered and
280 	 * configure all PPIs as level-triggered.
281 	 */
282 	for (i = 0; i < VGIC_NR_PRIVATE_IRQS; i++) {
283 		struct vgic_irq *irq = &vgic_cpu->private_irqs[i];
284 
285 		INIT_LIST_HEAD(&irq->ap_list);
286 		raw_spin_lock_init(&irq->irq_lock);
287 		irq->intid = i;
288 		irq->vcpu = NULL;
289 		irq->target_vcpu = vcpu;
290 		refcount_set(&irq->refcount, 0);
291 		if (vgic_irq_is_sgi(i)) {
292 			/* SGIs */
293 			irq->enabled = 1;
294 			irq->config = VGIC_CONFIG_EDGE;
295 		} else {
296 			/* PPIs */
297 			irq->config = VGIC_CONFIG_LEVEL;
298 		}
299 
300 		switch (type) {
301 		case KVM_DEV_TYPE_ARM_VGIC_V3:
302 			irq->group = 1;
303 			irq->mpidr = kvm_vcpu_get_mpidr_aff(vcpu);
304 			break;
305 		case KVM_DEV_TYPE_ARM_VGIC_V2:
306 			irq->group = 0;
307 			irq->targets = BIT(vcpu->vcpu_id);
308 			break;
309 		}
310 	}
311 
312 	return 0;
313 }
314 
vgic_allocate_private_irqs(struct kvm_vcpu * vcpu,u32 type)315 static int vgic_allocate_private_irqs(struct kvm_vcpu *vcpu, u32 type)
316 {
317 	int ret;
318 
319 	mutex_lock(&vcpu->kvm->arch.config_lock);
320 	ret = vgic_allocate_private_irqs_locked(vcpu, type);
321 	mutex_unlock(&vcpu->kvm->arch.config_lock);
322 
323 	return ret;
324 }
325 
326 /**
327  * kvm_vgic_vcpu_init() - Initialize static VGIC VCPU data
328  * structures and register VCPU-specific KVM iodevs
329  *
330  * @vcpu: pointer to the VCPU being created and initialized
331  *
332  * Only do initialization, but do not actually enable the
333  * VGIC CPU interface
334  */
kvm_vgic_vcpu_init(struct kvm_vcpu * vcpu)335 int kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu)
336 {
337 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
338 	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
339 	int ret = 0;
340 
341 	vgic_cpu->rd_iodev.base_addr = VGIC_ADDR_UNDEF;
342 
343 	INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
344 	raw_spin_lock_init(&vgic_cpu->ap_list_lock);
345 	atomic_set(&vgic_cpu->vgic_v3.its_vpe.vlpi_count, 0);
346 
347 	if (!irqchip_in_kernel(vcpu->kvm))
348 		return 0;
349 
350 	ret = vgic_allocate_private_irqs(vcpu, dist->vgic_model);
351 	if (ret)
352 		return ret;
353 
354 	/*
355 	 * If we are creating a VCPU with a GICv3 we must also register the
356 	 * KVM io device for the redistributor that belongs to this VCPU.
357 	 */
358 	if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) {
359 		mutex_lock(&vcpu->kvm->slots_lock);
360 		ret = vgic_register_redist_iodev(vcpu);
361 		mutex_unlock(&vcpu->kvm->slots_lock);
362 	}
363 	return ret;
364 }
365 
kvm_vgic_vcpu_enable(struct kvm_vcpu * vcpu)366 static void kvm_vgic_vcpu_enable(struct kvm_vcpu *vcpu)
367 {
368 	if (kvm_vgic_global_state.type == VGIC_V2)
369 		vgic_v2_enable(vcpu);
370 	else
371 		vgic_v3_enable(vcpu);
372 }
373 
374 /*
375  * vgic_init: allocates and initializes dist and vcpu data structures
376  * depending on two dimensioning parameters:
377  * - the number of spis
378  * - the number of vcpus
379  * The function is generally called when nr_spis has been explicitly set
380  * by the guest through the KVM DEVICE API. If not nr_spis is set to 256.
381  * vgic_initialized() returns true when this function has succeeded.
382  */
vgic_init(struct kvm * kvm)383 int vgic_init(struct kvm *kvm)
384 {
385 	struct vgic_dist *dist = &kvm->arch.vgic;
386 	struct kvm_vcpu *vcpu;
387 	int ret = 0;
388 	unsigned long idx;
389 
390 	lockdep_assert_held(&kvm->arch.config_lock);
391 
392 	if (vgic_initialized(kvm))
393 		return 0;
394 
395 	/* Are we also in the middle of creating a VCPU? */
396 	if (kvm->created_vcpus != atomic_read(&kvm->online_vcpus))
397 		return -EBUSY;
398 
399 	/* freeze the number of spis */
400 	if (!dist->nr_spis)
401 		dist->nr_spis = VGIC_NR_IRQS_LEGACY - VGIC_NR_PRIVATE_IRQS;
402 
403 	ret = kvm_vgic_dist_init(kvm, dist->nr_spis);
404 	if (ret)
405 		goto out;
406 
407 	/*
408 	 * Ensure vPEs are allocated if direct IRQ injection (e.g. vSGIs,
409 	 * vLPIs) is supported.
410 	 */
411 	if (vgic_supports_direct_irqs(kvm)) {
412 		ret = vgic_v4_init(kvm);
413 		if (ret)
414 			goto out;
415 	}
416 
417 	kvm_for_each_vcpu(idx, vcpu, kvm)
418 		kvm_vgic_vcpu_enable(vcpu);
419 
420 	ret = kvm_vgic_setup_default_irq_routing(kvm);
421 	if (ret)
422 		goto out;
423 
424 	vgic_debug_init(kvm);
425 	dist->initialized = true;
426 out:
427 	return ret;
428 }
429 
kvm_vgic_dist_destroy(struct kvm * kvm)430 static void kvm_vgic_dist_destroy(struct kvm *kvm)
431 {
432 	struct vgic_dist *dist = &kvm->arch.vgic;
433 	struct vgic_redist_region *rdreg, *next;
434 
435 	dist->ready = false;
436 	dist->initialized = false;
437 
438 	kfree(dist->spis);
439 	dist->spis = NULL;
440 	dist->nr_spis = 0;
441 	dist->vgic_dist_base = VGIC_ADDR_UNDEF;
442 
443 	if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) {
444 		list_for_each_entry_safe(rdreg, next, &dist->rd_regions, list)
445 			vgic_v3_free_redist_region(kvm, rdreg);
446 		INIT_LIST_HEAD(&dist->rd_regions);
447 	} else {
448 		dist->vgic_cpu_base = VGIC_ADDR_UNDEF;
449 	}
450 
451 	if (vgic_supports_direct_irqs(kvm))
452 		vgic_v4_teardown(kvm);
453 
454 	xa_destroy(&dist->lpi_xa);
455 }
456 
__kvm_vgic_vcpu_destroy(struct kvm_vcpu * vcpu)457 static void __kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
458 {
459 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
460 
461 	/*
462 	 * Retire all pending LPIs on this vcpu anyway as we're
463 	 * going to destroy it.
464 	 */
465 	vgic_flush_pending_lpis(vcpu);
466 
467 	INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
468 	kfree(vgic_cpu->private_irqs);
469 	vgic_cpu->private_irqs = NULL;
470 
471 	if (vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) {
472 		/*
473 		 * If this vCPU is being destroyed because of a failed creation
474 		 * then unregister the redistributor to avoid leaving behind a
475 		 * dangling pointer to the vCPU struct.
476 		 *
477 		 * vCPUs that have been successfully created (i.e. added to
478 		 * kvm->vcpu_array) get unregistered in kvm_vgic_destroy(), as
479 		 * this function gets called while holding kvm->arch.config_lock
480 		 * in the VM teardown path and would otherwise introduce a lock
481 		 * inversion w.r.t. kvm->srcu.
482 		 *
483 		 * vCPUs that failed creation are torn down outside of the
484 		 * kvm->arch.config_lock and do not get unregistered in
485 		 * kvm_vgic_destroy(), meaning it is both safe and necessary to
486 		 * do so here.
487 		 */
488 		if (kvm_get_vcpu_by_id(vcpu->kvm, vcpu->vcpu_id) != vcpu)
489 			vgic_unregister_redist_iodev(vcpu);
490 
491 		vgic_cpu->rd_iodev.base_addr = VGIC_ADDR_UNDEF;
492 	}
493 }
494 
kvm_vgic_vcpu_destroy(struct kvm_vcpu * vcpu)495 void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
496 {
497 	struct kvm *kvm = vcpu->kvm;
498 
499 	mutex_lock(&kvm->slots_lock);
500 	__kvm_vgic_vcpu_destroy(vcpu);
501 	mutex_unlock(&kvm->slots_lock);
502 }
503 
kvm_vgic_destroy(struct kvm * kvm)504 void kvm_vgic_destroy(struct kvm *kvm)
505 {
506 	struct kvm_vcpu *vcpu;
507 	unsigned long i;
508 
509 	mutex_lock(&kvm->slots_lock);
510 	mutex_lock(&kvm->arch.config_lock);
511 
512 	vgic_debug_destroy(kvm);
513 
514 	kvm_for_each_vcpu(i, vcpu, kvm)
515 		__kvm_vgic_vcpu_destroy(vcpu);
516 
517 	kvm_vgic_dist_destroy(kvm);
518 
519 	mutex_unlock(&kvm->arch.config_lock);
520 
521 	if (kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3)
522 		kvm_for_each_vcpu(i, vcpu, kvm)
523 			vgic_unregister_redist_iodev(vcpu);
524 
525 	mutex_unlock(&kvm->slots_lock);
526 }
527 
528 /**
529  * vgic_lazy_init: Lazy init is only allowed if the GIC exposed to the guest
530  * is a GICv2. A GICv3 must be explicitly initialized by userspace using the
531  * KVM_DEV_ARM_VGIC_GRP_CTRL KVM_DEVICE group.
532  * @kvm: kvm struct pointer
533  */
vgic_lazy_init(struct kvm * kvm)534 int vgic_lazy_init(struct kvm *kvm)
535 {
536 	int ret = 0;
537 
538 	if (unlikely(!vgic_initialized(kvm))) {
539 		/*
540 		 * We only provide the automatic initialization of the VGIC
541 		 * for the legacy case of a GICv2. Any other type must
542 		 * be explicitly initialized once setup with the respective
543 		 * KVM device call.
544 		 */
545 		if (kvm->arch.vgic.vgic_model != KVM_DEV_TYPE_ARM_VGIC_V2)
546 			return -EBUSY;
547 
548 		mutex_lock(&kvm->arch.config_lock);
549 		ret = vgic_init(kvm);
550 		mutex_unlock(&kvm->arch.config_lock);
551 	}
552 
553 	return ret;
554 }
555 
556 /* RESOURCE MAPPING */
557 
558 /**
559  * kvm_vgic_map_resources - map the MMIO regions
560  * @kvm: kvm struct pointer
561  *
562  * Map the MMIO regions depending on the VGIC model exposed to the guest
563  * called on the first VCPU run.
564  * Also map the virtual CPU interface into the VM.
565  * v2 calls vgic_init() if not already done.
566  * v3 and derivatives return an error if the VGIC is not initialized.
567  */
kvm_vgic_map_resources(struct kvm * kvm)568 int kvm_vgic_map_resources(struct kvm *kvm)
569 {
570 	struct vgic_dist *dist = &kvm->arch.vgic;
571 	enum vgic_type type;
572 	gpa_t dist_base;
573 	int ret = 0;
574 
575 	if (likely(smp_load_acquire(&dist->ready)))
576 		return 0;
577 
578 	mutex_lock(&kvm->slots_lock);
579 	mutex_lock(&kvm->arch.config_lock);
580 	if (dist->ready)
581 		goto out;
582 
583 	if (!irqchip_in_kernel(kvm))
584 		goto out;
585 
586 	if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2) {
587 		ret = vgic_v2_map_resources(kvm);
588 		type = VGIC_V2;
589 	} else {
590 		ret = vgic_v3_map_resources(kvm);
591 		type = VGIC_V3;
592 	}
593 
594 	if (ret)
595 		goto out;
596 
597 	dist_base = dist->vgic_dist_base;
598 	mutex_unlock(&kvm->arch.config_lock);
599 
600 	ret = vgic_register_dist_iodev(kvm, dist_base, type);
601 	if (ret) {
602 		kvm_err("Unable to register VGIC dist MMIO regions\n");
603 		goto out_slots;
604 	}
605 
606 	smp_store_release(&dist->ready, true);
607 	goto out_slots;
608 out:
609 	mutex_unlock(&kvm->arch.config_lock);
610 out_slots:
611 	if (ret)
612 		kvm_vm_dead(kvm);
613 
614 	mutex_unlock(&kvm->slots_lock);
615 
616 	return ret;
617 }
618 
619 /* GENERIC PROBE */
620 
kvm_vgic_cpu_up(void)621 void kvm_vgic_cpu_up(void)
622 {
623 	enable_percpu_irq(kvm_vgic_global_state.maint_irq, 0);
624 }
625 
626 
kvm_vgic_cpu_down(void)627 void kvm_vgic_cpu_down(void)
628 {
629 	disable_percpu_irq(kvm_vgic_global_state.maint_irq);
630 }
631 
vgic_maintenance_handler(int irq,void * data)632 static irqreturn_t vgic_maintenance_handler(int irq, void *data)
633 {
634 	struct kvm_vcpu *vcpu = *(struct kvm_vcpu **)data;
635 
636 	/*
637 	 * We cannot rely on the vgic maintenance interrupt to be
638 	 * delivered synchronously. This means we can only use it to
639 	 * exit the VM, and we perform the handling of EOIed
640 	 * interrupts on the exit path (see vgic_fold_lr_state).
641 	 *
642 	 * Of course, NV throws a wrench in this plan, and needs
643 	 * something special.
644 	 */
645 	if (vcpu && vgic_state_is_nested(vcpu))
646 		vgic_v3_handle_nested_maint_irq(vcpu);
647 
648 	return IRQ_HANDLED;
649 }
650 
651 static struct gic_kvm_info *gic_kvm_info;
652 
vgic_set_kvm_info(const struct gic_kvm_info * info)653 void __init vgic_set_kvm_info(const struct gic_kvm_info *info)
654 {
655 	BUG_ON(gic_kvm_info != NULL);
656 	gic_kvm_info = kmalloc(sizeof(*info), GFP_KERNEL);
657 	if (gic_kvm_info)
658 		*gic_kvm_info = *info;
659 }
660 
661 /**
662  * kvm_vgic_init_cpu_hardware - initialize the GIC VE hardware
663  *
664  * For a specific CPU, initialize the GIC VE hardware.
665  */
kvm_vgic_init_cpu_hardware(void)666 void kvm_vgic_init_cpu_hardware(void)
667 {
668 	BUG_ON(preemptible());
669 
670 	/*
671 	 * We want to make sure the list registers start out clear so that we
672 	 * only have the program the used registers.
673 	 */
674 	if (kvm_vgic_global_state.type == VGIC_V2) {
675 		vgic_v2_init_lrs();
676 	} else if (kvm_vgic_global_state.type == VGIC_V3 ||
677 		   kvm_vgic_global_state.has_gcie_v3_compat) {
678 		kvm_call_hyp(__vgic_v3_init_lrs);
679 	}
680 }
681 
682 /**
683  * kvm_vgic_hyp_init: populates the kvm_vgic_global_state variable
684  * according to the host GIC model. Accordingly calls either
685  * vgic_v2/v3_probe which registers the KVM_DEVICE that can be
686  * instantiated by a guest later on .
687  */
kvm_vgic_hyp_init(void)688 int kvm_vgic_hyp_init(void)
689 {
690 	bool has_mask;
691 	int ret;
692 
693 	if (!gic_kvm_info)
694 		return -ENODEV;
695 
696 	has_mask = !gic_kvm_info->no_maint_irq_mask;
697 
698 	if (has_mask && !gic_kvm_info->maint_irq) {
699 		kvm_err("No vgic maintenance irq\n");
700 		return -ENXIO;
701 	}
702 
703 	/*
704 	 * If we get one of these oddball non-GICs, taint the kernel,
705 	 * as we have no idea of how they *really* behave.
706 	 */
707 	if (gic_kvm_info->no_hw_deactivation) {
708 		kvm_info("Non-architectural vgic, tainting kernel\n");
709 		add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK);
710 		kvm_vgic_global_state.no_hw_deactivation = true;
711 	}
712 
713 	switch (gic_kvm_info->type) {
714 	case GIC_V2:
715 		ret = vgic_v2_probe(gic_kvm_info);
716 		break;
717 	case GIC_V3:
718 		ret = vgic_v3_probe(gic_kvm_info);
719 		if (!ret) {
720 			static_branch_enable(&kvm_vgic_global_state.gicv3_cpuif);
721 			kvm_info("GIC system register CPU interface enabled\n");
722 		}
723 		break;
724 	case GIC_V5:
725 		ret = vgic_v5_probe(gic_kvm_info);
726 		break;
727 	default:
728 		ret = -ENODEV;
729 	}
730 
731 	kvm_vgic_global_state.maint_irq = gic_kvm_info->maint_irq;
732 
733 	kfree(gic_kvm_info);
734 	gic_kvm_info = NULL;
735 
736 	if (ret)
737 		return ret;
738 
739 	if (!has_mask && !kvm_vgic_global_state.maint_irq)
740 		return 0;
741 
742 	ret = request_percpu_irq(kvm_vgic_global_state.maint_irq,
743 				 vgic_maintenance_handler,
744 				 "vgic", kvm_get_running_vcpus());
745 	if (ret) {
746 		kvm_err("Cannot register interrupt %d\n",
747 			kvm_vgic_global_state.maint_irq);
748 		return ret;
749 	}
750 
751 	kvm_info("vgic interrupt IRQ%d\n", kvm_vgic_global_state.maint_irq);
752 	return 0;
753 }
754