xref: /linux/arch/x86/kvm/irq_comm.c (revision f8e17c17b81070f38062dce79ca7f4541851dadd)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * irq_comm.c: Common API for in kernel interrupt controller
4  * Copyright (c) 2007, Intel Corporation.
5  *
6  * Authors:
7  *   Yaozu (Eddie) Dong <Eddie.dong@intel.com>
8  *
9  * Copyright 2010 Red Hat, Inc. and/or its affiliates.
10  */
11 
12 #include <linux/kvm_host.h>
13 #include <linux/slab.h>
14 #include <linux/export.h>
15 #include <linux/rculist.h>
16 
17 #include <trace/events/kvm.h>
18 
19 #include <asm/msidef.h>
20 
21 #include "irq.h"
22 
23 #include "ioapic.h"
24 
25 #include "lapic.h"
26 
27 #include "hyperv.h"
28 #include "x86.h"
29 
30 static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
31 			   struct kvm *kvm, int irq_source_id, int level,
32 			   bool line_status)
33 {
34 	struct kvm_pic *pic = kvm->arch.vpic;
35 	return kvm_pic_set_irq(pic, e->irqchip.pin, irq_source_id, level);
36 }
37 
38 static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
39 			      struct kvm *kvm, int irq_source_id, int level,
40 			      bool line_status)
41 {
42 	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
43 	return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, irq_source_id, level,
44 				line_status);
45 }
46 
47 int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
48 		struct kvm_lapic_irq *irq, struct dest_map *dest_map)
49 {
50 	int i, r = -1;
51 	struct kvm_vcpu *vcpu, *lowest = NULL;
52 	unsigned long dest_vcpu_bitmap[BITS_TO_LONGS(KVM_MAX_VCPUS)];
53 	unsigned int dest_vcpus = 0;
54 
55 	if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
56 		return r;
57 
58 	if (irq->dest_mode == APIC_DEST_PHYSICAL &&
59 	    irq->dest_id == 0xff && kvm_lowest_prio_delivery(irq)) {
60 		printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
61 		irq->delivery_mode = APIC_DM_FIXED;
62 	}
63 
64 	memset(dest_vcpu_bitmap, 0, sizeof(dest_vcpu_bitmap));
65 
66 	kvm_for_each_vcpu(i, vcpu, kvm) {
67 		if (!kvm_apic_present(vcpu))
68 			continue;
69 
70 		if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
71 					irq->dest_id, irq->dest_mode))
72 			continue;
73 
74 		if (!kvm_lowest_prio_delivery(irq)) {
75 			if (r < 0)
76 				r = 0;
77 			r += kvm_apic_set_irq(vcpu, irq, dest_map);
78 		} else if (kvm_apic_sw_enabled(vcpu->arch.apic)) {
79 			if (!kvm_vector_hashing_enabled()) {
80 				if (!lowest)
81 					lowest = vcpu;
82 				else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
83 					lowest = vcpu;
84 			} else {
85 				__set_bit(i, dest_vcpu_bitmap);
86 				dest_vcpus++;
87 			}
88 		}
89 	}
90 
91 	if (dest_vcpus != 0) {
92 		int idx = kvm_vector_to_index(irq->vector, dest_vcpus,
93 					dest_vcpu_bitmap, KVM_MAX_VCPUS);
94 
95 		lowest = kvm_get_vcpu(kvm, idx);
96 	}
97 
98 	if (lowest)
99 		r = kvm_apic_set_irq(lowest, irq, dest_map);
100 
101 	return r;
102 }
103 
104 void kvm_set_msi_irq(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *e,
105 		     struct kvm_lapic_irq *irq)
106 {
107 	trace_kvm_msi_set_irq(e->msi.address_lo | (kvm->arch.x2apic_format ?
108 	                                     (u64)e->msi.address_hi << 32 : 0),
109 	                      e->msi.data);
110 
111 	irq->dest_id = (e->msi.address_lo &
112 			MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
113 	if (kvm->arch.x2apic_format)
114 		irq->dest_id |= MSI_ADDR_EXT_DEST_ID(e->msi.address_hi);
115 	irq->vector = (e->msi.data &
116 			MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
117 	irq->dest_mode = kvm_lapic_irq_dest_mode(
118 	    !!((1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo));
119 	irq->trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
120 	irq->delivery_mode = e->msi.data & 0x700;
121 	irq->msi_redir_hint = ((e->msi.address_lo
122 		& MSI_ADDR_REDIRECTION_LOWPRI) > 0);
123 	irq->level = 1;
124 	irq->shorthand = APIC_DEST_NOSHORT;
125 }
126 EXPORT_SYMBOL_GPL(kvm_set_msi_irq);
127 
128 static inline bool kvm_msi_route_invalid(struct kvm *kvm,
129 		struct kvm_kernel_irq_routing_entry *e)
130 {
131 	return kvm->arch.x2apic_format && (e->msi.address_hi & 0xff);
132 }
133 
134 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
135 		struct kvm *kvm, int irq_source_id, int level, bool line_status)
136 {
137 	struct kvm_lapic_irq irq;
138 
139 	if (kvm_msi_route_invalid(kvm, e))
140 		return -EINVAL;
141 
142 	if (!level)
143 		return -1;
144 
145 	kvm_set_msi_irq(kvm, e, &irq);
146 
147 	return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
148 }
149 
150 
151 static int kvm_hv_set_sint(struct kvm_kernel_irq_routing_entry *e,
152 		    struct kvm *kvm, int irq_source_id, int level,
153 		    bool line_status)
154 {
155 	if (!level)
156 		return -1;
157 
158 	return kvm_hv_synic_set_irq(kvm, e->hv_sint.vcpu, e->hv_sint.sint);
159 }
160 
161 int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
162 			      struct kvm *kvm, int irq_source_id, int level,
163 			      bool line_status)
164 {
165 	struct kvm_lapic_irq irq;
166 	int r;
167 
168 	switch (e->type) {
169 	case KVM_IRQ_ROUTING_HV_SINT:
170 		return kvm_hv_set_sint(e, kvm, irq_source_id, level,
171 				       line_status);
172 
173 	case KVM_IRQ_ROUTING_MSI:
174 		if (kvm_msi_route_invalid(kvm, e))
175 			return -EINVAL;
176 
177 		kvm_set_msi_irq(kvm, e, &irq);
178 
179 		if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
180 			return r;
181 		break;
182 
183 	default:
184 		break;
185 	}
186 
187 	return -EWOULDBLOCK;
188 }
189 
190 int kvm_request_irq_source_id(struct kvm *kvm)
191 {
192 	unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
193 	int irq_source_id;
194 
195 	mutex_lock(&kvm->irq_lock);
196 	irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
197 
198 	if (irq_source_id >= BITS_PER_LONG) {
199 		printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
200 		irq_source_id = -EFAULT;
201 		goto unlock;
202 	}
203 
204 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
205 	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
206 	set_bit(irq_source_id, bitmap);
207 unlock:
208 	mutex_unlock(&kvm->irq_lock);
209 
210 	return irq_source_id;
211 }
212 
213 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
214 {
215 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
216 	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
217 
218 	mutex_lock(&kvm->irq_lock);
219 	if (irq_source_id < 0 ||
220 	    irq_source_id >= BITS_PER_LONG) {
221 		printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
222 		goto unlock;
223 	}
224 	clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
225 	if (!irqchip_kernel(kvm))
226 		goto unlock;
227 
228 	kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
229 	kvm_pic_clear_all(kvm->arch.vpic, irq_source_id);
230 unlock:
231 	mutex_unlock(&kvm->irq_lock);
232 }
233 
234 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
235 				    struct kvm_irq_mask_notifier *kimn)
236 {
237 	mutex_lock(&kvm->irq_lock);
238 	kimn->irq = irq;
239 	hlist_add_head_rcu(&kimn->link, &kvm->arch.mask_notifier_list);
240 	mutex_unlock(&kvm->irq_lock);
241 }
242 
243 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
244 				      struct kvm_irq_mask_notifier *kimn)
245 {
246 	mutex_lock(&kvm->irq_lock);
247 	hlist_del_rcu(&kimn->link);
248 	mutex_unlock(&kvm->irq_lock);
249 	synchronize_srcu(&kvm->irq_srcu);
250 }
251 
252 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
253 			     bool mask)
254 {
255 	struct kvm_irq_mask_notifier *kimn;
256 	int idx, gsi;
257 
258 	idx = srcu_read_lock(&kvm->irq_srcu);
259 	gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
260 	if (gsi != -1)
261 		hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
262 			if (kimn->irq == gsi)
263 				kimn->func(kimn, mask);
264 	srcu_read_unlock(&kvm->irq_srcu, idx);
265 }
266 
267 bool kvm_arch_can_set_irq_routing(struct kvm *kvm)
268 {
269 	return irqchip_in_kernel(kvm);
270 }
271 
272 int kvm_set_routing_entry(struct kvm *kvm,
273 			  struct kvm_kernel_irq_routing_entry *e,
274 			  const struct kvm_irq_routing_entry *ue)
275 {
276 	/* We can't check irqchip_in_kernel() here as some callers are
277 	 * currently inititalizing the irqchip. Other callers should therefore
278 	 * check kvm_arch_can_set_irq_routing() before calling this function.
279 	 */
280 	switch (ue->type) {
281 	case KVM_IRQ_ROUTING_IRQCHIP:
282 		if (irqchip_split(kvm))
283 			return -EINVAL;
284 		e->irqchip.pin = ue->u.irqchip.pin;
285 		switch (ue->u.irqchip.irqchip) {
286 		case KVM_IRQCHIP_PIC_SLAVE:
287 			e->irqchip.pin += PIC_NUM_PINS / 2;
288 			/* fall through */
289 		case KVM_IRQCHIP_PIC_MASTER:
290 			if (ue->u.irqchip.pin >= PIC_NUM_PINS / 2)
291 				return -EINVAL;
292 			e->set = kvm_set_pic_irq;
293 			break;
294 		case KVM_IRQCHIP_IOAPIC:
295 			if (ue->u.irqchip.pin >= KVM_IOAPIC_NUM_PINS)
296 				return -EINVAL;
297 			e->set = kvm_set_ioapic_irq;
298 			break;
299 		default:
300 			return -EINVAL;
301 		}
302 		e->irqchip.irqchip = ue->u.irqchip.irqchip;
303 		break;
304 	case KVM_IRQ_ROUTING_MSI:
305 		e->set = kvm_set_msi;
306 		e->msi.address_lo = ue->u.msi.address_lo;
307 		e->msi.address_hi = ue->u.msi.address_hi;
308 		e->msi.data = ue->u.msi.data;
309 
310 		if (kvm_msi_route_invalid(kvm, e))
311 			return -EINVAL;
312 		break;
313 	case KVM_IRQ_ROUTING_HV_SINT:
314 		e->set = kvm_hv_set_sint;
315 		e->hv_sint.vcpu = ue->u.hv_sint.vcpu;
316 		e->hv_sint.sint = ue->u.hv_sint.sint;
317 		break;
318 	default:
319 		return -EINVAL;
320 	}
321 
322 	return 0;
323 }
324 
325 bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
326 			     struct kvm_vcpu **dest_vcpu)
327 {
328 	int i, r = 0;
329 	struct kvm_vcpu *vcpu;
330 
331 	if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
332 		return true;
333 
334 	kvm_for_each_vcpu(i, vcpu, kvm) {
335 		if (!kvm_apic_present(vcpu))
336 			continue;
337 
338 		if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand,
339 					irq->dest_id, irq->dest_mode))
340 			continue;
341 
342 		if (++r == 2)
343 			return false;
344 
345 		*dest_vcpu = vcpu;
346 	}
347 
348 	return r == 1;
349 }
350 EXPORT_SYMBOL_GPL(kvm_intr_is_single_vcpu);
351 
352 #define IOAPIC_ROUTING_ENTRY(irq) \
353 	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
354 	  .u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
355 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
356 
357 #define PIC_ROUTING_ENTRY(irq) \
358 	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
359 	  .u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
360 #define ROUTING_ENTRY2(irq) \
361 	IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
362 
363 static const struct kvm_irq_routing_entry default_routing[] = {
364 	ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
365 	ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
366 	ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
367 	ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
368 	ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
369 	ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
370 	ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
371 	ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
372 	ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
373 	ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
374 	ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
375 	ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
376 };
377 
378 int kvm_setup_default_irq_routing(struct kvm *kvm)
379 {
380 	return kvm_set_irq_routing(kvm, default_routing,
381 				   ARRAY_SIZE(default_routing), 0);
382 }
383 
384 static const struct kvm_irq_routing_entry empty_routing[] = {};
385 
386 int kvm_setup_empty_irq_routing(struct kvm *kvm)
387 {
388 	return kvm_set_irq_routing(kvm, empty_routing, 0, 0);
389 }
390 
391 void kvm_arch_post_irq_routing_update(struct kvm *kvm)
392 {
393 	if (!irqchip_split(kvm))
394 		return;
395 	kvm_make_scan_ioapic_request(kvm);
396 }
397 
398 void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu,
399 			    ulong *ioapic_handled_vectors)
400 {
401 	struct kvm *kvm = vcpu->kvm;
402 	struct kvm_kernel_irq_routing_entry *entry;
403 	struct kvm_irq_routing_table *table;
404 	u32 i, nr_ioapic_pins;
405 	int idx;
406 
407 	idx = srcu_read_lock(&kvm->irq_srcu);
408 	table = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
409 	nr_ioapic_pins = min_t(u32, table->nr_rt_entries,
410 			       kvm->arch.nr_reserved_ioapic_pins);
411 	for (i = 0; i < nr_ioapic_pins; ++i) {
412 		hlist_for_each_entry(entry, &table->map[i], link) {
413 			struct kvm_lapic_irq irq;
414 
415 			if (entry->type != KVM_IRQ_ROUTING_MSI)
416 				continue;
417 
418 			kvm_set_msi_irq(vcpu->kvm, entry, &irq);
419 
420 			if (irq.level &&
421 			    kvm_apic_match_dest(vcpu, NULL, APIC_DEST_NOSHORT,
422 						irq.dest_id, irq.dest_mode))
423 				__set_bit(irq.vector, ioapic_handled_vectors);
424 		}
425 	}
426 	srcu_read_unlock(&kvm->irq_srcu, idx);
427 }
428 
429 void kvm_arch_irq_routing_update(struct kvm *kvm)
430 {
431 	kvm_hv_irq_routing_update(kvm);
432 }
433