xref: /openbmc/linux/arch/x86/kvm/irq_comm.c (revision e52a6321)
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 (irq->dest_mode == 0 && irq->dest_id == 0xff &&
56 			kvm_lowest_prio_delivery(irq)) {
57 		printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
58 		irq->delivery_mode = APIC_DM_FIXED;
59 	}
60 
61 	if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
62 		return r;
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 = (1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo;
118 	irq->trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
119 	irq->delivery_mode = e->msi.data & 0x700;
120 	irq->msi_redir_hint = ((e->msi.address_lo
121 		& MSI_ADDR_REDIRECTION_LOWPRI) > 0);
122 	irq->level = 1;
123 	irq->shorthand = 0;
124 }
125 EXPORT_SYMBOL_GPL(kvm_set_msi_irq);
126 
127 static inline bool kvm_msi_route_invalid(struct kvm *kvm,
128 		struct kvm_kernel_irq_routing_entry *e)
129 {
130 	return kvm->arch.x2apic_format && (e->msi.address_hi & 0xff);
131 }
132 
133 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
134 		struct kvm *kvm, int irq_source_id, int level, bool line_status)
135 {
136 	struct kvm_lapic_irq irq;
137 
138 	if (kvm_msi_route_invalid(kvm, e))
139 		return -EINVAL;
140 
141 	if (!level)
142 		return -1;
143 
144 	kvm_set_msi_irq(kvm, e, &irq);
145 
146 	return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
147 }
148 
149 
150 static int kvm_hv_set_sint(struct kvm_kernel_irq_routing_entry *e,
151 		    struct kvm *kvm, int irq_source_id, int level,
152 		    bool line_status)
153 {
154 	if (!level)
155 		return -1;
156 
157 	return kvm_hv_synic_set_irq(kvm, e->hv_sint.vcpu, e->hv_sint.sint);
158 }
159 
160 int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
161 			      struct kvm *kvm, int irq_source_id, int level,
162 			      bool line_status)
163 {
164 	struct kvm_lapic_irq irq;
165 	int r;
166 
167 	switch (e->type) {
168 	case KVM_IRQ_ROUTING_HV_SINT:
169 		return kvm_hv_set_sint(e, kvm, irq_source_id, level,
170 				       line_status);
171 
172 	case KVM_IRQ_ROUTING_MSI:
173 		if (kvm_msi_route_invalid(kvm, e))
174 			return -EINVAL;
175 
176 		kvm_set_msi_irq(kvm, e, &irq);
177 
178 		if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
179 			return r;
180 		break;
181 
182 	default:
183 		break;
184 	}
185 
186 	return -EWOULDBLOCK;
187 }
188 
189 int kvm_request_irq_source_id(struct kvm *kvm)
190 {
191 	unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
192 	int irq_source_id;
193 
194 	mutex_lock(&kvm->irq_lock);
195 	irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
196 
197 	if (irq_source_id >= BITS_PER_LONG) {
198 		printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
199 		irq_source_id = -EFAULT;
200 		goto unlock;
201 	}
202 
203 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
204 	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
205 	set_bit(irq_source_id, bitmap);
206 unlock:
207 	mutex_unlock(&kvm->irq_lock);
208 
209 	return irq_source_id;
210 }
211 
212 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
213 {
214 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
215 	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
216 
217 	mutex_lock(&kvm->irq_lock);
218 	if (irq_source_id < 0 ||
219 	    irq_source_id >= BITS_PER_LONG) {
220 		printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
221 		goto unlock;
222 	}
223 	clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
224 	if (!irqchip_kernel(kvm))
225 		goto unlock;
226 
227 	kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
228 	kvm_pic_clear_all(kvm->arch.vpic, irq_source_id);
229 unlock:
230 	mutex_unlock(&kvm->irq_lock);
231 }
232 
233 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
234 				    struct kvm_irq_mask_notifier *kimn)
235 {
236 	mutex_lock(&kvm->irq_lock);
237 	kimn->irq = irq;
238 	hlist_add_head_rcu(&kimn->link, &kvm->arch.mask_notifier_list);
239 	mutex_unlock(&kvm->irq_lock);
240 }
241 
242 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
243 				      struct kvm_irq_mask_notifier *kimn)
244 {
245 	mutex_lock(&kvm->irq_lock);
246 	hlist_del_rcu(&kimn->link);
247 	mutex_unlock(&kvm->irq_lock);
248 	synchronize_srcu(&kvm->irq_srcu);
249 }
250 
251 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
252 			     bool mask)
253 {
254 	struct kvm_irq_mask_notifier *kimn;
255 	int idx, gsi;
256 
257 	idx = srcu_read_lock(&kvm->irq_srcu);
258 	gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
259 	if (gsi != -1)
260 		hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
261 			if (kimn->irq == gsi)
262 				kimn->func(kimn, mask);
263 	srcu_read_unlock(&kvm->irq_srcu, idx);
264 }
265 
266 bool kvm_arch_can_set_irq_routing(struct kvm *kvm)
267 {
268 	return irqchip_in_kernel(kvm);
269 }
270 
271 int kvm_set_routing_entry(struct kvm *kvm,
272 			  struct kvm_kernel_irq_routing_entry *e,
273 			  const struct kvm_irq_routing_entry *ue)
274 {
275 	/* We can't check irqchip_in_kernel() here as some callers are
276 	 * currently inititalizing the irqchip. Other callers should therefore
277 	 * check kvm_arch_can_set_irq_routing() before calling this function.
278 	 */
279 	switch (ue->type) {
280 	case KVM_IRQ_ROUTING_IRQCHIP:
281 		if (irqchip_split(kvm))
282 			return -EINVAL;
283 		e->irqchip.pin = ue->u.irqchip.pin;
284 		switch (ue->u.irqchip.irqchip) {
285 		case KVM_IRQCHIP_PIC_SLAVE:
286 			e->irqchip.pin += PIC_NUM_PINS / 2;
287 			/* fall through */
288 		case KVM_IRQCHIP_PIC_MASTER:
289 			if (ue->u.irqchip.pin >= PIC_NUM_PINS / 2)
290 				return -EINVAL;
291 			e->set = kvm_set_pic_irq;
292 			break;
293 		case KVM_IRQCHIP_IOAPIC:
294 			if (ue->u.irqchip.pin >= KVM_IOAPIC_NUM_PINS)
295 				return -EINVAL;
296 			e->set = kvm_set_ioapic_irq;
297 			break;
298 		default:
299 			return -EINVAL;
300 		}
301 		e->irqchip.irqchip = ue->u.irqchip.irqchip;
302 		break;
303 	case KVM_IRQ_ROUTING_MSI:
304 		e->set = kvm_set_msi;
305 		e->msi.address_lo = ue->u.msi.address_lo;
306 		e->msi.address_hi = ue->u.msi.address_hi;
307 		e->msi.data = ue->u.msi.data;
308 
309 		if (kvm_msi_route_invalid(kvm, e))
310 			return -EINVAL;
311 		break;
312 	case KVM_IRQ_ROUTING_HV_SINT:
313 		e->set = kvm_hv_set_sint;
314 		e->hv_sint.vcpu = ue->u.hv_sint.vcpu;
315 		e->hv_sint.sint = ue->u.hv_sint.sint;
316 		break;
317 	default:
318 		return -EINVAL;
319 	}
320 
321 	return 0;
322 }
323 
324 bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
325 			     struct kvm_vcpu **dest_vcpu)
326 {
327 	int i, r = 0;
328 	struct kvm_vcpu *vcpu;
329 
330 	if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
331 		return true;
332 
333 	kvm_for_each_vcpu(i, vcpu, kvm) {
334 		if (!kvm_apic_present(vcpu))
335 			continue;
336 
337 		if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand,
338 					irq->dest_id, irq->dest_mode))
339 			continue;
340 
341 		if (++r == 2)
342 			return false;
343 
344 		*dest_vcpu = vcpu;
345 	}
346 
347 	return r == 1;
348 }
349 EXPORT_SYMBOL_GPL(kvm_intr_is_single_vcpu);
350 
351 #define IOAPIC_ROUTING_ENTRY(irq) \
352 	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
353 	  .u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
354 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
355 
356 #define PIC_ROUTING_ENTRY(irq) \
357 	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
358 	  .u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
359 #define ROUTING_ENTRY2(irq) \
360 	IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
361 
362 static const struct kvm_irq_routing_entry default_routing[] = {
363 	ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
364 	ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
365 	ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
366 	ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
367 	ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
368 	ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
369 	ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
370 	ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
371 	ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
372 	ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
373 	ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
374 	ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
375 };
376 
377 int kvm_setup_default_irq_routing(struct kvm *kvm)
378 {
379 	return kvm_set_irq_routing(kvm, default_routing,
380 				   ARRAY_SIZE(default_routing), 0);
381 }
382 
383 static const struct kvm_irq_routing_entry empty_routing[] = {};
384 
385 int kvm_setup_empty_irq_routing(struct kvm *kvm)
386 {
387 	return kvm_set_irq_routing(kvm, empty_routing, 0, 0);
388 }
389 
390 void kvm_arch_post_irq_routing_update(struct kvm *kvm)
391 {
392 	if (!irqchip_split(kvm))
393 		return;
394 	kvm_make_scan_ioapic_request(kvm);
395 }
396 
397 void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu,
398 			    ulong *ioapic_handled_vectors)
399 {
400 	struct kvm *kvm = vcpu->kvm;
401 	struct kvm_kernel_irq_routing_entry *entry;
402 	struct kvm_irq_routing_table *table;
403 	u32 i, nr_ioapic_pins;
404 	int idx;
405 
406 	idx = srcu_read_lock(&kvm->irq_srcu);
407 	table = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
408 	nr_ioapic_pins = min_t(u32, table->nr_rt_entries,
409 			       kvm->arch.nr_reserved_ioapic_pins);
410 	for (i = 0; i < nr_ioapic_pins; ++i) {
411 		hlist_for_each_entry(entry, &table->map[i], link) {
412 			struct kvm_lapic_irq irq;
413 
414 			if (entry->type != KVM_IRQ_ROUTING_MSI)
415 				continue;
416 
417 			kvm_set_msi_irq(vcpu->kvm, entry, &irq);
418 
419 			if (irq.level && kvm_apic_match_dest(vcpu, NULL, 0,
420 						irq.dest_id, irq.dest_mode))
421 				__set_bit(irq.vector, ioapic_handled_vectors);
422 		}
423 	}
424 	srcu_read_unlock(&kvm->irq_srcu, idx);
425 }
426 
427 void kvm_arch_irq_routing_update(struct kvm *kvm)
428 {
429 	kvm_hv_irq_routing_update(kvm);
430 }
431