2 * Copyright (C) 2015, 2016 ARM Ltd.
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
17 #include <linux/uaccess.h>
18 #include <linux/interrupt.h>
19 #include <linux/cpu.h>
20 #include <linux/kvm_host.h>
21 #include <kvm/arm_vgic.h>
22 #include <asm/kvm_mmu.h>
26 * Initialization rules: there are multiple stages to the vgic
27 * initialization, both for the distributor and the CPU interfaces. The basic
28 * idea is that even though the VGIC is not functional or not requested from
29 * user space, the critical path of the run loop can still call VGIC functions
30 * that just won't do anything, without them having to check additional
31 * initialization flags to ensure they don't look at uninitialized data
36 * - kvm_vgic_early_init(): initialization of static data that doesn't
37 * depend on any sizing information or emulation type. No allocation
40 * - vgic_init(): allocation and initialization of the generic data
41 * structures that depend on sizing information (number of CPUs,
42 * number of interrupts). Also initializes the vcpu specific data
43 * structures. Can be executed lazily for GICv2.
47 * - kvm_vgic_vcpu_early_init(): initialization of static data that
48 * doesn't depend on any sizing information or emulation type. No
49 * allocation is allowed there.
55 * kvm_vgic_early_init() - Initialize static VGIC VCPU data structures
56 * @kvm: The VM whose VGIC districutor should be initialized
58 * Only do initialization of static structures that don't require any
59 * allocation or sizing information from userspace. vgic_init() called
60 * kvm_vgic_dist_init() which takes care of the rest.
62 void kvm_vgic_early_init(struct kvm *kvm)
64 struct vgic_dist *dist = &kvm->arch.vgic;
66 INIT_LIST_HEAD(&dist->lpi_list_head);
67 spin_lock_init(&dist->lpi_list_lock);
71 * kvm_vgic_vcpu_early_init() - Initialize static VGIC VCPU data structures
72 * @vcpu: The VCPU whose VGIC data structures whould be initialized
74 * Only do initialization, but do not actually enable the VGIC CPU interface
77 void kvm_vgic_vcpu_early_init(struct kvm_vcpu *vcpu)
79 struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
82 INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
83 spin_lock_init(&vgic_cpu->ap_list_lock);
86 * Enable and configure all SGIs to be edge-triggered and
87 * configure all PPIs as level-triggered.
89 for (i = 0; i < VGIC_NR_PRIVATE_IRQS; i++) {
90 struct vgic_irq *irq = &vgic_cpu->private_irqs[i];
92 INIT_LIST_HEAD(&irq->ap_list);
93 spin_lock_init(&irq->irq_lock);
96 irq->target_vcpu = vcpu;
97 irq->targets = 1U << vcpu->vcpu_id;
98 kref_init(&irq->refcount);
99 if (vgic_irq_is_sgi(i)) {
102 irq->config = VGIC_CONFIG_EDGE;
105 irq->config = VGIC_CONFIG_LEVEL;
113 * kvm_vgic_create: triggered by the instantiation of the VGIC device by
114 * user space, either through the legacy KVM_CREATE_IRQCHIP ioctl (v2 only)
115 * or through the generic KVM_CREATE_DEVICE API ioctl.
116 * irqchip_in_kernel() tells you if this function succeeded or not.
117 * @kvm: kvm struct pointer
118 * @type: KVM_DEV_TYPE_ARM_VGIC_V[23]
120 int kvm_vgic_create(struct kvm *kvm, u32 type)
122 int i, vcpu_lock_idx = -1, ret;
123 struct kvm_vcpu *vcpu;
125 if (irqchip_in_kernel(kvm))
129 * This function is also called by the KVM_CREATE_IRQCHIP handler,
130 * which had no chance yet to check the availability of the GICv2
131 * emulation. So check this here again. KVM_CREATE_DEVICE does
132 * the proper checks already.
134 if (type == KVM_DEV_TYPE_ARM_VGIC_V2 &&
135 !kvm_vgic_global_state.can_emulate_gicv2)
139 * Any time a vcpu is run, vcpu_load is called which tries to grab the
140 * vcpu->mutex. By grabbing the vcpu->mutex of all VCPUs we ensure
141 * that no other VCPUs are run while we create the vgic.
144 kvm_for_each_vcpu(i, vcpu, kvm) {
145 if (!mutex_trylock(&vcpu->mutex))
150 kvm_for_each_vcpu(i, vcpu, kvm) {
151 if (vcpu->arch.has_run_once)
156 if (type == KVM_DEV_TYPE_ARM_VGIC_V2)
157 kvm->arch.max_vcpus = VGIC_V2_MAX_CPUS;
159 kvm->arch.max_vcpus = VGIC_V3_MAX_CPUS;
161 if (atomic_read(&kvm->online_vcpus) > kvm->arch.max_vcpus) {
166 kvm->arch.vgic.in_kernel = true;
167 kvm->arch.vgic.vgic_model = type;
169 kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
170 kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
171 kvm->arch.vgic.vgic_redist_base = VGIC_ADDR_UNDEF;
174 for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
175 vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx);
176 mutex_unlock(&vcpu->mutex);
184 * kvm_vgic_dist_init: initialize the dist data structures
185 * @kvm: kvm struct pointer
186 * @nr_spis: number of spis, frozen by caller
188 static int kvm_vgic_dist_init(struct kvm *kvm, unsigned int nr_spis)
190 struct vgic_dist *dist = &kvm->arch.vgic;
191 struct kvm_vcpu *vcpu0 = kvm_get_vcpu(kvm, 0);
194 dist->spis = kcalloc(nr_spis, sizeof(struct vgic_irq), GFP_KERNEL);
199 * In the following code we do not take the irq struct lock since
200 * no other action on irq structs can happen while the VGIC is
201 * not initialized yet:
202 * If someone wants to inject an interrupt or does a MMIO access, we
203 * require prior initialization in case of a virtual GICv3 or trigger
204 * initialization when using a virtual GICv2.
206 for (i = 0; i < nr_spis; i++) {
207 struct vgic_irq *irq = &dist->spis[i];
209 irq->intid = i + VGIC_NR_PRIVATE_IRQS;
210 INIT_LIST_HEAD(&irq->ap_list);
211 spin_lock_init(&irq->irq_lock);
213 irq->target_vcpu = vcpu0;
214 kref_init(&irq->refcount);
215 if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2)
224 * kvm_vgic_vcpu_init() - Register VCPU-specific KVM iodevs
225 * @vcpu: pointer to the VCPU being created and initialized
227 int kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu)
230 struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
232 if (!irqchip_in_kernel(vcpu->kvm))
236 * If we are creating a VCPU with a GICv3 we must also register the
237 * KVM io device for the redistributor that belongs to this VCPU.
239 if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) {
240 mutex_lock(&vcpu->kvm->lock);
241 ret = vgic_register_redist_iodev(vcpu);
242 mutex_unlock(&vcpu->kvm->lock);
247 static void kvm_vgic_vcpu_enable(struct kvm_vcpu *vcpu)
249 if (kvm_vgic_global_state.type == VGIC_V2)
250 vgic_v2_enable(vcpu);
252 vgic_v3_enable(vcpu);
256 * vgic_init: allocates and initializes dist and vcpu data structures
257 * depending on two dimensioning parameters:
258 * - the number of spis
259 * - the number of vcpus
260 * The function is generally called when nr_spis has been explicitly set
261 * by the guest through the KVM DEVICE API. If not nr_spis is set to 256.
262 * vgic_initialized() returns true when this function has succeeded.
263 * Must be called with kvm->lock held!
265 int vgic_init(struct kvm *kvm)
267 struct vgic_dist *dist = &kvm->arch.vgic;
268 struct kvm_vcpu *vcpu;
271 if (vgic_initialized(kvm))
274 /* freeze the number of spis */
276 dist->nr_spis = VGIC_NR_IRQS_LEGACY - VGIC_NR_PRIVATE_IRQS;
278 ret = kvm_vgic_dist_init(kvm, dist->nr_spis);
282 if (vgic_has_its(kvm)) {
283 ret = vgic_v4_init(kvm);
288 kvm_for_each_vcpu(i, vcpu, kvm)
289 kvm_vgic_vcpu_enable(vcpu);
291 ret = kvm_vgic_setup_default_irq_routing(kvm);
295 vgic_debug_init(kvm);
297 dist->initialized = true;
303 static void kvm_vgic_dist_destroy(struct kvm *kvm)
305 struct vgic_dist *dist = &kvm->arch.vgic;
308 dist->initialized = false;
313 if (vgic_supports_direct_msis(kvm))
314 vgic_v4_teardown(kvm);
317 void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
319 struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
321 INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
324 /* To be called with kvm->lock held */
325 static void __kvm_vgic_destroy(struct kvm *kvm)
327 struct kvm_vcpu *vcpu;
330 vgic_debug_destroy(kvm);
332 kvm_vgic_dist_destroy(kvm);
334 kvm_for_each_vcpu(i, vcpu, kvm)
335 kvm_vgic_vcpu_destroy(vcpu);
338 void kvm_vgic_destroy(struct kvm *kvm)
340 mutex_lock(&kvm->lock);
341 __kvm_vgic_destroy(kvm);
342 mutex_unlock(&kvm->lock);
346 * vgic_lazy_init: Lazy init is only allowed if the GIC exposed to the guest
347 * is a GICv2. A GICv3 must be explicitly initialized by the guest using the
348 * KVM_DEV_ARM_VGIC_GRP_CTRL KVM_DEVICE group.
349 * @kvm: kvm struct pointer
351 int vgic_lazy_init(struct kvm *kvm)
355 if (unlikely(!vgic_initialized(kvm))) {
357 * We only provide the automatic initialization of the VGIC
358 * for the legacy case of a GICv2. Any other type must
359 * be explicitly initialized once setup with the respective
362 if (kvm->arch.vgic.vgic_model != KVM_DEV_TYPE_ARM_VGIC_V2)
365 mutex_lock(&kvm->lock);
366 ret = vgic_init(kvm);
367 mutex_unlock(&kvm->lock);
373 /* RESOURCE MAPPING */
376 * Map the MMIO regions depending on the VGIC model exposed to the guest
377 * called on the first VCPU run.
378 * Also map the virtual CPU interface into the VM.
379 * v2/v3 derivatives call vgic_init if not already done.
380 * vgic_ready() returns true if this function has succeeded.
381 * @kvm: kvm struct pointer
383 int kvm_vgic_map_resources(struct kvm *kvm)
385 struct vgic_dist *dist = &kvm->arch.vgic;
388 mutex_lock(&kvm->lock);
389 if (!irqchip_in_kernel(kvm))
392 if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2)
393 ret = vgic_v2_map_resources(kvm);
395 ret = vgic_v3_map_resources(kvm);
398 __kvm_vgic_destroy(kvm);
401 mutex_unlock(&kvm->lock);
407 static int vgic_init_cpu_starting(unsigned int cpu)
409 enable_percpu_irq(kvm_vgic_global_state.maint_irq, 0);
414 static int vgic_init_cpu_dying(unsigned int cpu)
416 disable_percpu_irq(kvm_vgic_global_state.maint_irq);
420 static irqreturn_t vgic_maintenance_handler(int irq, void *data)
423 * We cannot rely on the vgic maintenance interrupt to be
424 * delivered synchronously. This means we can only use it to
425 * exit the VM, and we perform the handling of EOIed
426 * interrupts on the exit path (see vgic_fold_lr_state).
432 * kvm_vgic_init_cpu_hardware - initialize the GIC VE hardware
434 * For a specific CPU, initialize the GIC VE hardware.
436 void kvm_vgic_init_cpu_hardware(void)
438 BUG_ON(preemptible());
441 * We want to make sure the list registers start out clear so that we
442 * only have the program the used registers.
444 if (kvm_vgic_global_state.type == VGIC_V2)
447 kvm_call_hyp(__vgic_v3_init_lrs);
451 * kvm_vgic_hyp_init: populates the kvm_vgic_global_state variable
452 * according to the host GIC model. Accordingly calls either
453 * vgic_v2/v3_probe which registers the KVM_DEVICE that can be
454 * instantiated by a guest later on .
456 int kvm_vgic_hyp_init(void)
458 const struct gic_kvm_info *gic_kvm_info;
461 gic_kvm_info = gic_get_kvm_info();
465 if (!gic_kvm_info->maint_irq) {
466 kvm_err("No vgic maintenance irq\n");
470 switch (gic_kvm_info->type) {
472 ret = vgic_v2_probe(gic_kvm_info);
475 ret = vgic_v3_probe(gic_kvm_info);
477 static_branch_enable(&kvm_vgic_global_state.gicv3_cpuif);
478 kvm_info("GIC system register CPU interface enabled\n");
488 kvm_vgic_global_state.maint_irq = gic_kvm_info->maint_irq;
489 ret = request_percpu_irq(kvm_vgic_global_state.maint_irq,
490 vgic_maintenance_handler,
491 "vgic", kvm_get_running_vcpus());
493 kvm_err("Cannot register interrupt %d\n",
494 kvm_vgic_global_state.maint_irq);
498 ret = cpuhp_setup_state(CPUHP_AP_KVM_ARM_VGIC_INIT_STARTING,
499 "kvm/arm/vgic:starting",
500 vgic_init_cpu_starting, vgic_init_cpu_dying);
502 kvm_err("Cannot register vgic CPU notifier\n");
506 kvm_info("vgic interrupt IRQ%d\n", kvm_vgic_global_state.maint_irq);
510 free_percpu_irq(kvm_vgic_global_state.maint_irq,
511 kvm_get_running_vcpus());