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KVM: arm/arm64: vgic-new: vgic_init: implement vgic_init
[mirror_ubuntu-zesty-kernel.git] / virt / kvm / arm / vgic / vgic-init.c
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1/*
2 * Copyright (C) 2015, 2016 ARM Ltd.
3 *
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.
7 *
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.
12 *
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/>.
15 */
16
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>
23#include "vgic.h"
24
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25/*
26 * Initialization rules: there are multiple stages to the vgic
27 * initialization, both for the distributor and the CPU interfaces.
28 *
29 * Distributor:
30 *
31 * - kvm_vgic_early_init(): initialization of static data that doesn't
32 * depend on any sizing information or emulation type. No allocation
33 * is allowed there.
34 *
35 * - vgic_init(): allocation and initialization of the generic data
36 * structures that depend on sizing information (number of CPUs,
37 * number of interrupts). Also initializes the vcpu specific data
38 * structures. Can be executed lazily for GICv2.
39 *
40 * CPU Interface:
41 *
42 * - kvm_vgic_cpu_early_init(): initialization of static data that
43 * doesn't depend on any sizing information or emulation type. No
44 * allocation is allowed there.
45 */
46
47/* EARLY INIT */
48
49/*
50 * Those 2 functions should not be needed anymore but they
51 * still are called from arm.c
52 */
53void kvm_vgic_early_init(struct kvm *kvm)
54{
55}
56
57void kvm_vgic_vcpu_early_init(struct kvm_vcpu *vcpu)
58{
59}
60
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61/* CREATION */
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.
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68 * @kvm: kvm struct pointer
69 * @type: KVM_DEV_TYPE_ARM_VGIC_V[23]
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70 */
71int kvm_vgic_create(struct kvm *kvm, u32 type)
72{
73 int i, vcpu_lock_idx = -1, ret;
74 struct kvm_vcpu *vcpu;
75
76 mutex_lock(&kvm->lock);
77
78 if (irqchip_in_kernel(kvm)) {
79 ret = -EEXIST;
80 goto out;
81 }
82
83 /*
84 * This function is also called by the KVM_CREATE_IRQCHIP handler,
85 * which had no chance yet to check the availability of the GICv2
86 * emulation. So check this here again. KVM_CREATE_DEVICE does
87 * the proper checks already.
88 */
89 if (type == KVM_DEV_TYPE_ARM_VGIC_V2 &&
90 !kvm_vgic_global_state.can_emulate_gicv2) {
91 ret = -ENODEV;
92 goto out;
93 }
94
95 /*
96 * Any time a vcpu is run, vcpu_load is called which tries to grab the
97 * vcpu->mutex. By grabbing the vcpu->mutex of all VCPUs we ensure
98 * that no other VCPUs are run while we create the vgic.
99 */
100 ret = -EBUSY;
101 kvm_for_each_vcpu(i, vcpu, kvm) {
102 if (!mutex_trylock(&vcpu->mutex))
103 goto out_unlock;
104 vcpu_lock_idx = i;
105 }
106
107 kvm_for_each_vcpu(i, vcpu, kvm) {
108 if (vcpu->arch.has_run_once)
109 goto out_unlock;
110 }
111 ret = 0;
112
113 if (type == KVM_DEV_TYPE_ARM_VGIC_V2)
114 kvm->arch.max_vcpus = VGIC_V2_MAX_CPUS;
115 else
116 kvm->arch.max_vcpus = VGIC_V3_MAX_CPUS;
117
118 if (atomic_read(&kvm->online_vcpus) > kvm->arch.max_vcpus) {
119 ret = -E2BIG;
120 goto out_unlock;
121 }
122
123 kvm->arch.vgic.in_kernel = true;
124 kvm->arch.vgic.vgic_model = type;
125
126 /*
127 * kvm_vgic_global_state.vctrl_base is set on vgic probe (kvm_arch_init)
128 * it is stored in distributor struct for asm save/restore purpose
129 */
130 kvm->arch.vgic.vctrl_base = kvm_vgic_global_state.vctrl_base;
131
132 kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
133 kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
134 kvm->arch.vgic.vgic_redist_base = VGIC_ADDR_UNDEF;
135
136out_unlock:
137 for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
138 vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx);
139 mutex_unlock(&vcpu->mutex);
140 }
141
142out:
143 mutex_unlock(&kvm->lock);
144 return ret;
145}
146
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147/* INIT/DESTROY */
148
149/**
150 * kvm_vgic_dist_init: initialize the dist data structures
151 * @kvm: kvm struct pointer
152 * @nr_spis: number of spis, frozen by caller
153 */
154static int kvm_vgic_dist_init(struct kvm *kvm, unsigned int nr_spis)
155{
156 struct vgic_dist *dist = &kvm->arch.vgic;
157 struct kvm_vcpu *vcpu0 = kvm_get_vcpu(kvm, 0);
158 int i;
159
160 dist->spis = kcalloc(nr_spis, sizeof(struct vgic_irq), GFP_KERNEL);
161 if (!dist->spis)
162 return -ENOMEM;
163
164 /*
165 * In the following code we do not take the irq struct lock since
166 * no other action on irq structs can happen while the VGIC is
167 * not initialized yet:
168 * If someone wants to inject an interrupt or does a MMIO access, we
169 * require prior initialization in case of a virtual GICv3 or trigger
170 * initialization when using a virtual GICv2.
171 */
172 for (i = 0; i < nr_spis; i++) {
173 struct vgic_irq *irq = &dist->spis[i];
174
175 irq->intid = i + VGIC_NR_PRIVATE_IRQS;
176 INIT_LIST_HEAD(&irq->ap_list);
177 spin_lock_init(&irq->irq_lock);
178 irq->vcpu = NULL;
179 irq->target_vcpu = vcpu0;
180 if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2)
181 irq->targets = 0;
182 else
183 irq->mpidr = 0;
184 }
185 return 0;
186}
187
188/**
189 * kvm_vgic_vcpu_init: initialize the vcpu data structures and
190 * enable the VCPU interface
191 * @vcpu: the VCPU which's VGIC should be initialized
192 */
193static void kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu)
194{
195 struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
196 int i;
197
198 INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
199 spin_lock_init(&vgic_cpu->ap_list_lock);
200
201 /*
202 * Enable and configure all SGIs to be edge-triggered and
203 * configure all PPIs as level-triggered.
204 */
205 for (i = 0; i < VGIC_NR_PRIVATE_IRQS; i++) {
206 struct vgic_irq *irq = &vgic_cpu->private_irqs[i];
207
208 INIT_LIST_HEAD(&irq->ap_list);
209 spin_lock_init(&irq->irq_lock);
210 irq->intid = i;
211 irq->vcpu = NULL;
212 irq->target_vcpu = vcpu;
213 irq->targets = 1U << vcpu->vcpu_id;
214 if (vgic_irq_is_sgi(i)) {
215 /* SGIs */
216 irq->enabled = 1;
217 irq->config = VGIC_CONFIG_EDGE;
218 } else {
219 /* PPIs */
220 irq->config = VGIC_CONFIG_LEVEL;
221 }
222 }
223 if (kvm_vgic_global_state.type == VGIC_V2)
224 vgic_v2_enable(vcpu);
225 else
226 vgic_v3_enable(vcpu);
227}
228
229/*
230 * vgic_init: allocates and initializes dist and vcpu data structures
231 * depending on two dimensioning parameters:
232 * - the number of spis
233 * - the number of vcpus
234 * The function is generally called when nr_spis has been explicitly set
235 * by the guest through the KVM DEVICE API. If not nr_spis is set to 256.
236 * vgic_initialized() returns true when this function has succeeded.
237 * Must be called with kvm->lock held!
238 */
239int vgic_init(struct kvm *kvm)
240{
241 struct vgic_dist *dist = &kvm->arch.vgic;
242 struct kvm_vcpu *vcpu;
243 int ret = 0, i;
244
245 if (vgic_initialized(kvm))
246 return 0;
247
248 /* freeze the number of spis */
249 if (!dist->nr_spis)
250 dist->nr_spis = VGIC_NR_IRQS_LEGACY - VGIC_NR_PRIVATE_IRQS;
251
252 ret = kvm_vgic_dist_init(kvm, dist->nr_spis);
253 if (ret)
254 goto out;
255
256 kvm_for_each_vcpu(i, vcpu, kvm)
257 kvm_vgic_vcpu_init(vcpu);
258
259 dist->initialized = true;
260out:
261 return ret;
262}
263
264static void kvm_vgic_dist_destroy(struct kvm *kvm)
265{
266 struct vgic_dist *dist = &kvm->arch.vgic;
267
268 mutex_lock(&kvm->lock);
269
270 dist->ready = false;
271 dist->initialized = false;
272
273 kfree(dist->spis);
274 kfree(dist->redist_iodevs);
275 dist->nr_spis = 0;
276
277 mutex_unlock(&kvm->lock);
278}
279
280void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
281{
282 struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
283
284 INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
285}
286
287void kvm_vgic_destroy(struct kvm *kvm)
288{
289 struct kvm_vcpu *vcpu;
290 int i;
291
292 kvm_vgic_dist_destroy(kvm);
293
294 kvm_for_each_vcpu(i, vcpu, kvm)
295 kvm_vgic_vcpu_destroy(vcpu);
296}
297
298/**
299 * vgic_lazy_init: Lazy init is only allowed if the GIC exposed to the guest
300 * is a GICv2. A GICv3 must be explicitly initialized by the guest using the
301 * KVM_DEV_ARM_VGIC_GRP_CTRL KVM_DEVICE group.
302 * @kvm: kvm struct pointer
303 */
304int vgic_lazy_init(struct kvm *kvm)
305{
306 int ret = 0;
307
308 if (unlikely(!vgic_initialized(kvm))) {
309 /*
310 * We only provide the automatic initialization of the VGIC
311 * for the legacy case of a GICv2. Any other type must
312 * be explicitly initialized once setup with the respective
313 * KVM device call.
314 */
315 if (kvm->arch.vgic.vgic_model != KVM_DEV_TYPE_ARM_VGIC_V2)
316 return -EBUSY;
317
318 mutex_lock(&kvm->lock);
319 ret = vgic_init(kvm);
320 mutex_unlock(&kvm->lock);
321 }
322
323 return ret;
324}
325
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326/* GENERIC PROBE */
327
328static void vgic_init_maintenance_interrupt(void *info)
329{
330 enable_percpu_irq(kvm_vgic_global_state.maint_irq, 0);
331}
332
333static int vgic_cpu_notify(struct notifier_block *self,
334 unsigned long action, void *cpu)
335{
336 switch (action) {
337 case CPU_STARTING:
338 case CPU_STARTING_FROZEN:
339 vgic_init_maintenance_interrupt(NULL);
340 break;
341 case CPU_DYING:
342 case CPU_DYING_FROZEN:
343 disable_percpu_irq(kvm_vgic_global_state.maint_irq);
344 break;
345 }
346
347 return NOTIFY_OK;
348}
349
350static struct notifier_block vgic_cpu_nb = {
351 .notifier_call = vgic_cpu_notify,
352};
353
354static irqreturn_t vgic_maintenance_handler(int irq, void *data)
355{
356 /*
357 * We cannot rely on the vgic maintenance interrupt to be
358 * delivered synchronously. This means we can only use it to
359 * exit the VM, and we perform the handling of EOIed
360 * interrupts on the exit path (see vgic_process_maintenance).
361 */
362 return IRQ_HANDLED;
363}
364
365/**
366 * kvm_vgic_hyp_init: populates the kvm_vgic_global_state variable
367 * according to the host GIC model. Accordingly calls either
368 * vgic_v2/v3_probe which registers the KVM_DEVICE that can be
369 * instantiated by a guest later on .
370 */
371int kvm_vgic_hyp_init(void)
372{
373 const struct gic_kvm_info *gic_kvm_info;
374 int ret;
375
376 gic_kvm_info = gic_get_kvm_info();
377 if (!gic_kvm_info)
378 return -ENODEV;
379
380 if (!gic_kvm_info->maint_irq) {
381 kvm_err("No vgic maintenance irq\n");
382 return -ENXIO;
383 }
384
385 switch (gic_kvm_info->type) {
386 case GIC_V2:
387 ret = vgic_v2_probe(gic_kvm_info);
388 break;
389 case GIC_V3:
390 ret = vgic_v3_probe(gic_kvm_info);
391 break;
392 default:
393 ret = -ENODEV;
394 };
395
396 if (ret)
397 return ret;
398
399 kvm_vgic_global_state.maint_irq = gic_kvm_info->maint_irq;
400 ret = request_percpu_irq(kvm_vgic_global_state.maint_irq,
401 vgic_maintenance_handler,
402 "vgic", kvm_get_running_vcpus());
403 if (ret) {
404 kvm_err("Cannot register interrupt %d\n",
405 kvm_vgic_global_state.maint_irq);
406 return ret;
407 }
408
409 ret = __register_cpu_notifier(&vgic_cpu_nb);
410 if (ret) {
411 kvm_err("Cannot register vgic CPU notifier\n");
412 goto out_free_irq;
413 }
414
415 on_each_cpu(vgic_init_maintenance_interrupt, NULL, 1);
416
417 kvm_info("vgic interrupt IRQ%d\n", kvm_vgic_global_state.maint_irq);
418 return 0;
419
420out_free_irq:
421 free_percpu_irq(kvm_vgic_global_state.maint_irq,
422 kvm_get_running_vcpus());
423 return ret;
424}