1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * VGIC MMIO handling functions
4 */
5
6#include <linux/bitops.h>
7#include <linux/bsearch.h>
8#include <linux/interrupt.h>
9#include <linux/irq.h>
10#include <linux/kvm.h>
11#include <linux/kvm_host.h>
12#include <kvm/iodev.h>
13#include <kvm/arm_arch_timer.h>
14#include <kvm/arm_vgic.h>
15
16#include "vgic.h"
17#include "vgic-mmio.h"
18
19unsigned long vgic_mmio_read_raz(struct kvm_vcpu *vcpu,
20 gpa_t addr, unsigned int len)
21{
22 return 0;
23}
24
25unsigned long vgic_mmio_read_rao(struct kvm_vcpu *vcpu,
26 gpa_t addr, unsigned int len)
27{
28 return -1UL;
29}
30
31void vgic_mmio_write_wi(struct kvm_vcpu *vcpu, gpa_t addr,
32 unsigned int len, unsigned long val)
33{
34 /* Ignore */
35}
36
37int vgic_mmio_uaccess_write_wi(struct kvm_vcpu *vcpu, gpa_t addr,
38 unsigned int len, unsigned long val)
39{
40 /* Ignore */
41 return 0;
42}
43
44unsigned long vgic_mmio_read_group(struct kvm_vcpu *vcpu,
45 gpa_t addr, unsigned int len)
46{
47 u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
48 u32 value = 0;
49 int i;
50
51 /* Loop over all IRQs affected by this read */
52 for (i = 0; i < len * 8; i++) {
53 struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, intid: intid + i);
54
55 if (irq->group)
56 value |= BIT(i);
57
58 vgic_put_irq(kvm: vcpu->kvm, irq);
59 }
60
61 return value;
62}
63
64static void vgic_update_vsgi(struct vgic_irq *irq)
65{
66 WARN_ON(its_prop_update_vsgi(irq->host_irq, irq->priority, irq->group));
67}
68
69void vgic_mmio_write_group(struct kvm_vcpu *vcpu, gpa_t addr,
70 unsigned int len, unsigned long val)
71{
72 u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
73 int i;
74 unsigned long flags;
75
76 for (i = 0; i < len * 8; i++) {
77 struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, intid: intid + i);
78
79 raw_spin_lock_irqsave(&irq->irq_lock, flags);
80 irq->group = !!(val & BIT(i));
81 if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
82 vgic_update_vsgi(irq);
83 raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
84 } else {
85 vgic_queue_irq_unlock(kvm: vcpu->kvm, irq, flags);
86 }
87
88 vgic_put_irq(kvm: vcpu->kvm, irq);
89 }
90}
91
92/*
93 * Read accesses to both GICD_ICENABLER and GICD_ISENABLER return the value
94 * of the enabled bit, so there is only one function for both here.
95 */
96unsigned long vgic_mmio_read_enable(struct kvm_vcpu *vcpu,
97 gpa_t addr, unsigned int len)
98{
99 u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
100 u32 value = 0;
101 int i;
102
103 /* Loop over all IRQs affected by this read */
104 for (i = 0; i < len * 8; i++) {
105 struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, intid: intid + i);
106
107 if (irq->enabled)
108 value |= (1U << i);
109
110 vgic_put_irq(kvm: vcpu->kvm, irq);
111 }
112
113 return value;
114}
115
116void vgic_mmio_write_senable(struct kvm_vcpu *vcpu,
117 gpa_t addr, unsigned int len,
118 unsigned long val)
119{
120 u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
121 int i;
122 unsigned long flags;
123
124 for_each_set_bit(i, &val, len * 8) {
125 struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, intid: intid + i);
126
127 raw_spin_lock_irqsave(&irq->irq_lock, flags);
128 if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
129 if (!irq->enabled) {
130 struct irq_data *data;
131
132 irq->enabled = true;
133 data = &irq_to_desc(irq: irq->host_irq)->irq_data;
134 while (irqd_irq_disabled(d: data))
135 enable_irq(irq: irq->host_irq);
136 }
137
138 raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
139 vgic_put_irq(kvm: vcpu->kvm, irq);
140
141 continue;
142 } else if (vgic_irq_is_mapped_level(irq)) {
143 bool was_high = irq->line_level;
144
145 /*
146 * We need to update the state of the interrupt because
147 * the guest might have changed the state of the device
148 * while the interrupt was disabled at the VGIC level.
149 */
150 irq->line_level = vgic_get_phys_line_level(irq);
151 /*
152 * Deactivate the physical interrupt so the GIC will let
153 * us know when it is asserted again.
154 */
155 if (!irq->active && was_high && !irq->line_level)
156 vgic_irq_set_phys_active(irq, active: false);
157 }
158 irq->enabled = true;
159 vgic_queue_irq_unlock(kvm: vcpu->kvm, irq, flags);
160
161 vgic_put_irq(kvm: vcpu->kvm, irq);
162 }
163}
164
165void vgic_mmio_write_cenable(struct kvm_vcpu *vcpu,
166 gpa_t addr, unsigned int len,
167 unsigned long val)
168{
169 u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
170 int i;
171 unsigned long flags;
172
173 for_each_set_bit(i, &val, len * 8) {
174 struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, intid: intid + i);
175
176 raw_spin_lock_irqsave(&irq->irq_lock, flags);
177 if (irq->hw && vgic_irq_is_sgi(irq->intid) && irq->enabled)
178 disable_irq_nosync(irq: irq->host_irq);
179
180 irq->enabled = false;
181
182 raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
183 vgic_put_irq(kvm: vcpu->kvm, irq);
184 }
185}
186
187int vgic_uaccess_write_senable(struct kvm_vcpu *vcpu,
188 gpa_t addr, unsigned int len,
189 unsigned long val)
190{
191 u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
192 int i;
193 unsigned long flags;
194
195 for_each_set_bit(i, &val, len * 8) {
196 struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, intid: intid + i);
197
198 raw_spin_lock_irqsave(&irq->irq_lock, flags);
199 irq->enabled = true;
200 vgic_queue_irq_unlock(kvm: vcpu->kvm, irq, flags);
201
202 vgic_put_irq(kvm: vcpu->kvm, irq);
203 }
204
205 return 0;
206}
207
208int vgic_uaccess_write_cenable(struct kvm_vcpu *vcpu,
209 gpa_t addr, unsigned int len,
210 unsigned long val)
211{
212 u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
213 int i;
214 unsigned long flags;
215
216 for_each_set_bit(i, &val, len * 8) {
217 struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, intid: intid + i);
218
219 raw_spin_lock_irqsave(&irq->irq_lock, flags);
220 irq->enabled = false;
221 raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
222
223 vgic_put_irq(kvm: vcpu->kvm, irq);
224 }
225
226 return 0;
227}
228
229static unsigned long __read_pending(struct kvm_vcpu *vcpu,
230 gpa_t addr, unsigned int len,
231 bool is_user)
232{
233 u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
234 u32 value = 0;
235 int i;
236
237 /* Loop over all IRQs affected by this read */
238 for (i = 0; i < len * 8; i++) {
239 struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, intid: intid + i);
240 unsigned long flags;
241 bool val;
242
243 /*
244 * When used from userspace with a GICv3 model:
245 *
246 * Pending state of interrupt is latched in pending_latch
247 * variable. Userspace will save and restore pending state
248 * and line_level separately.
249 * Refer to Documentation/virt/kvm/devices/arm-vgic-v3.rst
250 * for handling of ISPENDR and ICPENDR.
251 */
252 raw_spin_lock_irqsave(&irq->irq_lock, flags);
253 if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
254 int err;
255
256 val = false;
257 err = irq_get_irqchip_state(irq: irq->host_irq,
258 which: IRQCHIP_STATE_PENDING,
259 state: &val);
260 WARN_RATELIMIT(err, "IRQ %d", irq->host_irq);
261 } else if (!is_user && vgic_irq_is_mapped_level(irq)) {
262 val = vgic_get_phys_line_level(irq);
263 } else {
264 switch (vcpu->kvm->arch.vgic.vgic_model) {
265 case KVM_DEV_TYPE_ARM_VGIC_V3:
266 if (is_user) {
267 val = irq->pending_latch;
268 break;
269 }
270 fallthrough;
271 default:
272 val = irq_is_pending(irq);
273 break;
274 }
275 }
276
277 value |= ((u32)val << i);
278 raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
279
280 vgic_put_irq(kvm: vcpu->kvm, irq);
281 }
282
283 return value;
284}
285
286unsigned long vgic_mmio_read_pending(struct kvm_vcpu *vcpu,
287 gpa_t addr, unsigned int len)
288{
289 return __read_pending(vcpu, addr, len, is_user: false);
290}
291
292unsigned long vgic_uaccess_read_pending(struct kvm_vcpu *vcpu,
293 gpa_t addr, unsigned int len)
294{
295 return __read_pending(vcpu, addr, len, is_user: true);
296}
297
298static bool is_vgic_v2_sgi(struct kvm_vcpu *vcpu, struct vgic_irq *irq)
299{
300 return (vgic_irq_is_sgi(irq->intid) &&
301 vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2);
302}
303
304static void __set_pending(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len,
305 unsigned long val, bool is_user)
306{
307 u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
308 int i;
309 unsigned long flags;
310
311 for_each_set_bit(i, &val, len * 8) {
312 struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, intid: intid + i);
313
314 /* GICD_ISPENDR0 SGI bits are WI when written from the guest. */
315 if (is_vgic_v2_sgi(vcpu, irq) && !is_user) {
316 vgic_put_irq(kvm: vcpu->kvm, irq);
317 continue;
318 }
319
320 raw_spin_lock_irqsave(&irq->irq_lock, flags);
321
322 /*
323 * GICv2 SGIs are terribly broken. We can't restore
324 * the source of the interrupt, so just pick the vcpu
325 * itself as the source...
326 */
327 if (is_vgic_v2_sgi(vcpu, irq))
328 irq->source |= BIT(vcpu->vcpu_id);
329
330 if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
331 /* HW SGI? Ask the GIC to inject it */
332 int err;
333 err = irq_set_irqchip_state(irq: irq->host_irq,
334 which: IRQCHIP_STATE_PENDING,
335 state: true);
336 WARN_RATELIMIT(err, "IRQ %d", irq->host_irq);
337
338 raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
339 vgic_put_irq(kvm: vcpu->kvm, irq);
340
341 continue;
342 }
343
344 irq->pending_latch = true;
345 if (irq->hw && !is_user)
346 vgic_irq_set_phys_active(irq, active: true);
347
348 vgic_queue_irq_unlock(kvm: vcpu->kvm, irq, flags);
349 vgic_put_irq(kvm: vcpu->kvm, irq);
350 }
351}
352
353void vgic_mmio_write_spending(struct kvm_vcpu *vcpu,
354 gpa_t addr, unsigned int len,
355 unsigned long val)
356{
357 __set_pending(vcpu, addr, len, val, is_user: false);
358}
359
360int vgic_uaccess_write_spending(struct kvm_vcpu *vcpu,
361 gpa_t addr, unsigned int len,
362 unsigned long val)
363{
364 __set_pending(vcpu, addr, len, val, is_user: true);
365 return 0;
366}
367
368/* Must be called with irq->irq_lock held */
369static void vgic_hw_irq_cpending(struct kvm_vcpu *vcpu, struct vgic_irq *irq)
370{
371 irq->pending_latch = false;
372
373 /*
374 * We don't want the guest to effectively mask the physical
375 * interrupt by doing a write to SPENDR followed by a write to
376 * CPENDR for HW interrupts, so we clear the active state on
377 * the physical side if the virtual interrupt is not active.
378 * This may lead to taking an additional interrupt on the
379 * host, but that should not be a problem as the worst that
380 * can happen is an additional vgic injection. We also clear
381 * the pending state to maintain proper semantics for edge HW
382 * interrupts.
383 */
384 vgic_irq_set_phys_pending(irq, pending: false);
385 if (!irq->active)
386 vgic_irq_set_phys_active(irq, active: false);
387}
388
389static void __clear_pending(struct kvm_vcpu *vcpu,
390 gpa_t addr, unsigned int len,
391 unsigned long val, bool is_user)
392{
393 u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
394 int i;
395 unsigned long flags;
396
397 for_each_set_bit(i, &val, len * 8) {
398 struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, intid: intid + i);
399
400 /* GICD_ICPENDR0 SGI bits are WI when written from the guest. */
401 if (is_vgic_v2_sgi(vcpu, irq) && !is_user) {
402 vgic_put_irq(kvm: vcpu->kvm, irq);
403 continue;
404 }
405
406 raw_spin_lock_irqsave(&irq->irq_lock, flags);
407
408 /*
409 * More fun with GICv2 SGIs! If we're clearing one of them
410 * from userspace, which source vcpu to clear? Let's not
411 * even think of it, and blow the whole set.
412 */
413 if (is_vgic_v2_sgi(vcpu, irq))
414 irq->source = 0;
415
416 if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
417 /* HW SGI? Ask the GIC to clear its pending bit */
418 int err;
419 err = irq_set_irqchip_state(irq: irq->host_irq,
420 which: IRQCHIP_STATE_PENDING,
421 state: false);
422 WARN_RATELIMIT(err, "IRQ %d", irq->host_irq);
423
424 raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
425 vgic_put_irq(kvm: vcpu->kvm, irq);
426
427 continue;
428 }
429
430 if (irq->hw && !is_user)
431 vgic_hw_irq_cpending(vcpu, irq);
432 else
433 irq->pending_latch = false;
434
435 raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
436 vgic_put_irq(kvm: vcpu->kvm, irq);
437 }
438}
439
440void vgic_mmio_write_cpending(struct kvm_vcpu *vcpu,
441 gpa_t addr, unsigned int len,
442 unsigned long val)
443{
444 __clear_pending(vcpu, addr, len, val, is_user: false);
445}
446
447int vgic_uaccess_write_cpending(struct kvm_vcpu *vcpu,
448 gpa_t addr, unsigned int len,
449 unsigned long val)
450{
451 __clear_pending(vcpu, addr, len, val, is_user: true);
452 return 0;
453}
454
455/*
456 * If we are fiddling with an IRQ's active state, we have to make sure the IRQ
457 * is not queued on some running VCPU's LRs, because then the change to the
458 * active state can be overwritten when the VCPU's state is synced coming back
459 * from the guest.
460 *
461 * For shared interrupts as well as GICv3 private interrupts accessed from the
462 * non-owning CPU, we have to stop all the VCPUs because interrupts can be
463 * migrated while we don't hold the IRQ locks and we don't want to be chasing
464 * moving targets.
465 *
466 * For GICv2 private interrupts we don't have to do anything because
467 * userspace accesses to the VGIC state already require all VCPUs to be
468 * stopped, and only the VCPU itself can modify its private interrupts
469 * active state, which guarantees that the VCPU is not running.
470 */
471static void vgic_access_active_prepare(struct kvm_vcpu *vcpu, u32 intid)
472{
473 if ((vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3 &&
474 vcpu != kvm_get_running_vcpu()) ||
475 intid >= VGIC_NR_PRIVATE_IRQS)
476 kvm_arm_halt_guest(vcpu->kvm);
477}
478
479/* See vgic_access_active_prepare */
480static void vgic_access_active_finish(struct kvm_vcpu *vcpu, u32 intid)
481{
482 if ((vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3 &&
483 vcpu != kvm_get_running_vcpu()) ||
484 intid >= VGIC_NR_PRIVATE_IRQS)
485 kvm_arm_resume_guest(vcpu->kvm);
486}
487
488static unsigned long __vgic_mmio_read_active(struct kvm_vcpu *vcpu,
489 gpa_t addr, unsigned int len)
490{
491 u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
492 u32 value = 0;
493 int i;
494
495 /* Loop over all IRQs affected by this read */
496 for (i = 0; i < len * 8; i++) {
497 struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, intid: intid + i);
498
499 /*
500 * Even for HW interrupts, don't evaluate the HW state as
501 * all the guest is interested in is the virtual state.
502 */
503 if (irq->active)
504 value |= (1U << i);
505
506 vgic_put_irq(kvm: vcpu->kvm, irq);
507 }
508
509 return value;
510}
511
512unsigned long vgic_mmio_read_active(struct kvm_vcpu *vcpu,
513 gpa_t addr, unsigned int len)
514{
515 u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
516 u32 val;
517
518 mutex_lock(&vcpu->kvm->arch.config_lock);
519 vgic_access_active_prepare(vcpu, intid);
520
521 val = __vgic_mmio_read_active(vcpu, addr, len);
522
523 vgic_access_active_finish(vcpu, intid);
524 mutex_unlock(lock: &vcpu->kvm->arch.config_lock);
525
526 return val;
527}
528
529unsigned long vgic_uaccess_read_active(struct kvm_vcpu *vcpu,
530 gpa_t addr, unsigned int len)
531{
532 return __vgic_mmio_read_active(vcpu, addr, len);
533}
534
535/* Must be called with irq->irq_lock held */
536static void vgic_hw_irq_change_active(struct kvm_vcpu *vcpu, struct vgic_irq *irq,
537 bool active, bool is_uaccess)
538{
539 if (is_uaccess)
540 return;
541
542 irq->active = active;
543 vgic_irq_set_phys_active(irq, active);
544}
545
546static void vgic_mmio_change_active(struct kvm_vcpu *vcpu, struct vgic_irq *irq,
547 bool active)
548{
549 unsigned long flags;
550 struct kvm_vcpu *requester_vcpu = kvm_get_running_vcpu();
551
552 raw_spin_lock_irqsave(&irq->irq_lock, flags);
553
554 if (irq->hw && !vgic_irq_is_sgi(irq->intid)) {
555 vgic_hw_irq_change_active(vcpu, irq, active, is_uaccess: !requester_vcpu);
556 } else if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
557 /*
558 * GICv4.1 VSGI feature doesn't track an active state,
559 * so let's not kid ourselves, there is nothing we can
560 * do here.
561 */
562 irq->active = false;
563 } else {
564 u32 model = vcpu->kvm->arch.vgic.vgic_model;
565 u8 active_source;
566
567 irq->active = active;
568
569 /*
570 * The GICv2 architecture indicates that the source CPUID for
571 * an SGI should be provided during an EOI which implies that
572 * the active state is stored somewhere, but at the same time
573 * this state is not architecturally exposed anywhere and we
574 * have no way of knowing the right source.
575 *
576 * This may lead to a VCPU not being able to receive
577 * additional instances of a particular SGI after migration
578 * for a GICv2 VM on some GIC implementations. Oh well.
579 */
580 active_source = (requester_vcpu) ? requester_vcpu->vcpu_id : 0;
581
582 if (model == KVM_DEV_TYPE_ARM_VGIC_V2 &&
583 active && vgic_irq_is_sgi(irq->intid))
584 irq->active_source = active_source;
585 }
586
587 if (irq->active)
588 vgic_queue_irq_unlock(kvm: vcpu->kvm, irq, flags);
589 else
590 raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
591}
592
593static void __vgic_mmio_write_cactive(struct kvm_vcpu *vcpu,
594 gpa_t addr, unsigned int len,
595 unsigned long val)
596{
597 u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
598 int i;
599
600 for_each_set_bit(i, &val, len * 8) {
601 struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, intid: intid + i);
602 vgic_mmio_change_active(vcpu, irq, active: false);
603 vgic_put_irq(kvm: vcpu->kvm, irq);
604 }
605}
606
607void vgic_mmio_write_cactive(struct kvm_vcpu *vcpu,
608 gpa_t addr, unsigned int len,
609 unsigned long val)
610{
611 u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
612
613 mutex_lock(&vcpu->kvm->arch.config_lock);
614 vgic_access_active_prepare(vcpu, intid);
615
616 __vgic_mmio_write_cactive(vcpu, addr, len, val);
617
618 vgic_access_active_finish(vcpu, intid);
619 mutex_unlock(lock: &vcpu->kvm->arch.config_lock);
620}
621
622int vgic_mmio_uaccess_write_cactive(struct kvm_vcpu *vcpu,
623 gpa_t addr, unsigned int len,
624 unsigned long val)
625{
626 __vgic_mmio_write_cactive(vcpu, addr, len, val);
627 return 0;
628}
629
630static void __vgic_mmio_write_sactive(struct kvm_vcpu *vcpu,
631 gpa_t addr, unsigned int len,
632 unsigned long val)
633{
634 u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
635 int i;
636
637 for_each_set_bit(i, &val, len * 8) {
638 struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, intid: intid + i);
639 vgic_mmio_change_active(vcpu, irq, active: true);
640 vgic_put_irq(kvm: vcpu->kvm, irq);
641 }
642}
643
644void vgic_mmio_write_sactive(struct kvm_vcpu *vcpu,
645 gpa_t addr, unsigned int len,
646 unsigned long val)
647{
648 u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
649
650 mutex_lock(&vcpu->kvm->arch.config_lock);
651 vgic_access_active_prepare(vcpu, intid);
652
653 __vgic_mmio_write_sactive(vcpu, addr, len, val);
654
655 vgic_access_active_finish(vcpu, intid);
656 mutex_unlock(lock: &vcpu->kvm->arch.config_lock);
657}
658
659int vgic_mmio_uaccess_write_sactive(struct kvm_vcpu *vcpu,
660 gpa_t addr, unsigned int len,
661 unsigned long val)
662{
663 __vgic_mmio_write_sactive(vcpu, addr, len, val);
664 return 0;
665}
666
667unsigned long vgic_mmio_read_priority(struct kvm_vcpu *vcpu,
668 gpa_t addr, unsigned int len)
669{
670 u32 intid = VGIC_ADDR_TO_INTID(addr, 8);
671 int i;
672 u64 val = 0;
673
674 for (i = 0; i < len; i++) {
675 struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, intid: intid + i);
676
677 val |= (u64)irq->priority << (i * 8);
678
679 vgic_put_irq(kvm: vcpu->kvm, irq);
680 }
681
682 return val;
683}
684
685/*
686 * We currently don't handle changing the priority of an interrupt that
687 * is already pending on a VCPU. If there is a need for this, we would
688 * need to make this VCPU exit and re-evaluate the priorities, potentially
689 * leading to this interrupt getting presented now to the guest (if it has
690 * been masked by the priority mask before).
691 */
692void vgic_mmio_write_priority(struct kvm_vcpu *vcpu,
693 gpa_t addr, unsigned int len,
694 unsigned long val)
695{
696 u32 intid = VGIC_ADDR_TO_INTID(addr, 8);
697 int i;
698 unsigned long flags;
699
700 for (i = 0; i < len; i++) {
701 struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, intid: intid + i);
702
703 raw_spin_lock_irqsave(&irq->irq_lock, flags);
704 /* Narrow the priority range to what we actually support */
705 irq->priority = (val >> (i * 8)) & GENMASK(7, 8 - VGIC_PRI_BITS);
706 if (irq->hw && vgic_irq_is_sgi(irq->intid))
707 vgic_update_vsgi(irq);
708 raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
709
710 vgic_put_irq(kvm: vcpu->kvm, irq);
711 }
712}
713
714unsigned long vgic_mmio_read_config(struct kvm_vcpu *vcpu,
715 gpa_t addr, unsigned int len)
716{
717 u32 intid = VGIC_ADDR_TO_INTID(addr, 2);
718 u32 value = 0;
719 int i;
720
721 for (i = 0; i < len * 4; i++) {
722 struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, intid: intid + i);
723
724 if (irq->config == VGIC_CONFIG_EDGE)
725 value |= (2U << (i * 2));
726
727 vgic_put_irq(kvm: vcpu->kvm, irq);
728 }
729
730 return value;
731}
732
733void vgic_mmio_write_config(struct kvm_vcpu *vcpu,
734 gpa_t addr, unsigned int len,
735 unsigned long val)
736{
737 u32 intid = VGIC_ADDR_TO_INTID(addr, 2);
738 int i;
739 unsigned long flags;
740
741 for (i = 0; i < len * 4; i++) {
742 struct vgic_irq *irq;
743
744 /*
745 * The configuration cannot be changed for SGIs in general,
746 * for PPIs this is IMPLEMENTATION DEFINED. The arch timer
747 * code relies on PPIs being level triggered, so we also
748 * make them read-only here.
749 */
750 if (intid + i < VGIC_NR_PRIVATE_IRQS)
751 continue;
752
753 irq = vgic_get_irq(kvm: vcpu->kvm, intid: intid + i);
754 raw_spin_lock_irqsave(&irq->irq_lock, flags);
755
756 if (test_bit(i * 2 + 1, &val))
757 irq->config = VGIC_CONFIG_EDGE;
758 else
759 irq->config = VGIC_CONFIG_LEVEL;
760
761 raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
762 vgic_put_irq(kvm: vcpu->kvm, irq);
763 }
764}
765
766u32 vgic_read_irq_line_level_info(struct kvm_vcpu *vcpu, u32 intid)
767{
768 int i;
769 u32 val = 0;
770 int nr_irqs = vcpu->kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS;
771
772 for (i = 0; i < 32; i++) {
773 struct vgic_irq *irq;
774
775 if ((intid + i) < VGIC_NR_SGIS || (intid + i) >= nr_irqs)
776 continue;
777
778 irq = vgic_get_vcpu_irq(vcpu, intid: intid + i);
779 if (irq->config == VGIC_CONFIG_LEVEL && irq->line_level)
780 val |= (1U << i);
781
782 vgic_put_irq(kvm: vcpu->kvm, irq);
783 }
784
785 return val;
786}
787
788void vgic_write_irq_line_level_info(struct kvm_vcpu *vcpu, u32 intid,
789 const u32 val)
790{
791 int i;
792 int nr_irqs = vcpu->kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS;
793 unsigned long flags;
794
795 for (i = 0; i < 32; i++) {
796 struct vgic_irq *irq;
797 bool new_level;
798
799 if ((intid + i) < VGIC_NR_SGIS || (intid + i) >= nr_irqs)
800 continue;
801
802 irq = vgic_get_vcpu_irq(vcpu, intid: intid + i);
803
804 /*
805 * Line level is set irrespective of irq type
806 * (level or edge) to avoid dependency that VM should
807 * restore irq config before line level.
808 */
809 new_level = !!(val & (1U << i));
810 raw_spin_lock_irqsave(&irq->irq_lock, flags);
811 irq->line_level = new_level;
812 if (new_level)
813 vgic_queue_irq_unlock(kvm: vcpu->kvm, irq, flags);
814 else
815 raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
816
817 vgic_put_irq(kvm: vcpu->kvm, irq);
818 }
819}
820
821static int match_region(const void *key, const void *elt)
822{
823 const unsigned int offset = (unsigned long)key;
824 const struct vgic_register_region *region = elt;
825
826 if (offset < region->reg_offset)
827 return -1;
828
829 if (offset >= region->reg_offset + region->len)
830 return 1;
831
832 return 0;
833}
834
835const struct vgic_register_region *
836vgic_find_mmio_region(const struct vgic_register_region *regions,
837 int nr_regions, unsigned int offset)
838{
839 return bsearch(key: (void *)(uintptr_t)offset, base: regions, num: nr_regions,
840 size: sizeof(regions[0]), cmp: match_region);
841}
842
843void vgic_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
844{
845 if (kvm_vgic_global_state.type == VGIC_V2)
846 vgic_v2_set_vmcr(vcpu, vmcr);
847 else
848 vgic_v3_set_vmcr(vcpu, vmcr);
849}
850
851void vgic_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
852{
853 if (kvm_vgic_global_state.type == VGIC_V2)
854 vgic_v2_get_vmcr(vcpu, vmcr);
855 else
856 vgic_v3_get_vmcr(vcpu, vmcr);
857}
858
859/*
860 * kvm_mmio_read_buf() returns a value in a format where it can be converted
861 * to a byte array and be directly observed as the guest wanted it to appear
862 * in memory if it had done the store itself, which is LE for the GIC, as the
863 * guest knows the GIC is always LE.
864 *
865 * We convert this value to the CPUs native format to deal with it as a data
866 * value.
867 */
868unsigned long vgic_data_mmio_bus_to_host(const void *val, unsigned int len)
869{
870 unsigned long data = kvm_mmio_read_buf(val, len);
871
872 switch (len) {
873 case 1:
874 return data;
875 case 2:
876 return le16_to_cpu(data);
877 case 4:
878 return le32_to_cpu(data);
879 default:
880 return le64_to_cpu(data);
881 }
882}
883
884/*
885 * kvm_mmio_write_buf() expects a value in a format such that if converted to
886 * a byte array it is observed as the guest would see it if it could perform
887 * the load directly. Since the GIC is LE, and the guest knows this, the
888 * guest expects a value in little endian format.
889 *
890 * We convert the data value from the CPUs native format to LE so that the
891 * value is returned in the proper format.
892 */
893void vgic_data_host_to_mmio_bus(void *buf, unsigned int len,
894 unsigned long data)
895{
896 switch (len) {
897 case 1:
898 break;
899 case 2:
900 data = cpu_to_le16(data);
901 break;
902 case 4:
903 data = cpu_to_le32(data);
904 break;
905 default:
906 data = cpu_to_le64(data);
907 }
908
909 kvm_mmio_write_buf(buf, len, data);
910}
911
912static
913struct vgic_io_device *kvm_to_vgic_iodev(const struct kvm_io_device *dev)
914{
915 return container_of(dev, struct vgic_io_device, dev);
916}
917
918static bool check_region(const struct kvm *kvm,
919 const struct vgic_register_region *region,
920 gpa_t addr, int len)
921{
922 int flags, nr_irqs = kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS;
923
924 switch (len) {
925 case sizeof(u8):
926 flags = VGIC_ACCESS_8bit;
927 break;
928 case sizeof(u32):
929 flags = VGIC_ACCESS_32bit;
930 break;
931 case sizeof(u64):
932 flags = VGIC_ACCESS_64bit;
933 break;
934 default:
935 return false;
936 }
937
938 if ((region->access_flags & flags) && IS_ALIGNED(addr, len)) {
939 if (!region->bits_per_irq)
940 return true;
941
942 /* Do we access a non-allocated IRQ? */
943 return VGIC_ADDR_TO_INTID(addr, region->bits_per_irq) < nr_irqs;
944 }
945
946 return false;
947}
948
949const struct vgic_register_region *
950vgic_get_mmio_region(struct kvm_vcpu *vcpu, struct vgic_io_device *iodev,
951 gpa_t addr, int len)
952{
953 const struct vgic_register_region *region;
954
955 region = vgic_find_mmio_region(regions: iodev->regions, nr_regions: iodev->nr_regions,
956 offset: addr - iodev->base_addr);
957 if (!region || !check_region(kvm: vcpu->kvm, region, addr, len))
958 return NULL;
959
960 return region;
961}
962
963static int vgic_uaccess_read(struct kvm_vcpu *vcpu, struct vgic_io_device *iodev,
964 gpa_t addr, u32 *val)
965{
966 const struct vgic_register_region *region;
967 struct kvm_vcpu *r_vcpu;
968
969 region = vgic_get_mmio_region(vcpu, iodev, addr, len: sizeof(u32));
970 if (!region) {
971 *val = 0;
972 return 0;
973 }
974
975 r_vcpu = iodev->redist_vcpu ? iodev->redist_vcpu : vcpu;
976 if (region->uaccess_read)
977 *val = region->uaccess_read(r_vcpu, addr, sizeof(u32));
978 else
979 *val = region->read(r_vcpu, addr, sizeof(u32));
980
981 return 0;
982}
983
984static int vgic_uaccess_write(struct kvm_vcpu *vcpu, struct vgic_io_device *iodev,
985 gpa_t addr, const u32 *val)
986{
987 const struct vgic_register_region *region;
988 struct kvm_vcpu *r_vcpu;
989
990 region = vgic_get_mmio_region(vcpu, iodev, addr, len: sizeof(u32));
991 if (!region)
992 return 0;
993
994 r_vcpu = iodev->redist_vcpu ? iodev->redist_vcpu : vcpu;
995 if (region->uaccess_write)
996 return region->uaccess_write(r_vcpu, addr, sizeof(u32), *val);
997
998 region->write(r_vcpu, addr, sizeof(u32), *val);
999 return 0;
1000}
1001
1002/*
1003 * Userland access to VGIC registers.
1004 */
1005int vgic_uaccess(struct kvm_vcpu *vcpu, struct vgic_io_device *dev,
1006 bool is_write, int offset, u32 *val)
1007{
1008 if (is_write)
1009 return vgic_uaccess_write(vcpu, iodev: dev, addr: offset, val);
1010 else
1011 return vgic_uaccess_read(vcpu, iodev: dev, addr: offset, val);
1012}
1013
1014static int dispatch_mmio_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
1015 gpa_t addr, int len, void *val)
1016{
1017 struct vgic_io_device *iodev = kvm_to_vgic_iodev(dev);
1018 const struct vgic_register_region *region;
1019 unsigned long data = 0;
1020
1021 region = vgic_get_mmio_region(vcpu, iodev, addr, len);
1022 if (!region) {
1023 memset(val, 0, len);
1024 return 0;
1025 }
1026
1027 switch (iodev->iodev_type) {
1028 case IODEV_CPUIF:
1029 data = region->read(vcpu, addr, len);
1030 break;
1031 case IODEV_DIST:
1032 data = region->read(vcpu, addr, len);
1033 break;
1034 case IODEV_REDIST:
1035 data = region->read(iodev->redist_vcpu, addr, len);
1036 break;
1037 case IODEV_ITS:
1038 data = region->its_read(vcpu->kvm, iodev->its, addr, len);
1039 break;
1040 }
1041
1042 vgic_data_host_to_mmio_bus(buf: val, len, data);
1043 return 0;
1044}
1045
1046static int dispatch_mmio_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
1047 gpa_t addr, int len, const void *val)
1048{
1049 struct vgic_io_device *iodev = kvm_to_vgic_iodev(dev);
1050 const struct vgic_register_region *region;
1051 unsigned long data = vgic_data_mmio_bus_to_host(val, len);
1052
1053 region = vgic_get_mmio_region(vcpu, iodev, addr, len);
1054 if (!region)
1055 return 0;
1056
1057 switch (iodev->iodev_type) {
1058 case IODEV_CPUIF:
1059 region->write(vcpu, addr, len, data);
1060 break;
1061 case IODEV_DIST:
1062 region->write(vcpu, addr, len, data);
1063 break;
1064 case IODEV_REDIST:
1065 region->write(iodev->redist_vcpu, addr, len, data);
1066 break;
1067 case IODEV_ITS:
1068 region->its_write(vcpu->kvm, iodev->its, addr, len, data);
1069 break;
1070 }
1071
1072 return 0;
1073}
1074
1075const struct kvm_io_device_ops kvm_io_gic_ops = {
1076 .read = dispatch_mmio_read,
1077 .write = dispatch_mmio_write,
1078};
1079
1080int vgic_register_dist_iodev(struct kvm *kvm, gpa_t dist_base_address,
1081 enum vgic_type type)
1082{
1083 struct vgic_io_device *io_device = &kvm->arch.vgic.dist_iodev;
1084 unsigned int len;
1085
1086 switch (type) {
1087 case VGIC_V2:
1088 len = vgic_v2_init_dist_iodev(dev: io_device);
1089 break;
1090 case VGIC_V3:
1091 len = vgic_v3_init_dist_iodev(dev: io_device);
1092 break;
1093 default:
1094 BUG();
1095 }
1096
1097 io_device->base_addr = dist_base_address;
1098 io_device->iodev_type = IODEV_DIST;
1099 io_device->redist_vcpu = NULL;
1100
1101 return kvm_io_bus_register_dev(kvm, bus_idx: KVM_MMIO_BUS, addr: dist_base_address,
1102 len, dev: &io_device->dev);
1103}
1104

source code of linux/arch/arm64/kvm/vgic/vgic-mmio.c