xref: /openbmc/linux/arch/x86/kvm/irq_comm.c (revision 099ab4fc)
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 "irq.h"
20 
21 #include "ioapic.h"
22 
23 #include "lapic.h"
24 
25 #include "hyperv.h"
26 #include "x86.h"
27 
28 static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
29 			   struct kvm *kvm, int irq_source_id, int level,
30 			   bool line_status)
31 {
32 	struct kvm_pic *pic = kvm->arch.vpic;
33 	return kvm_pic_set_irq(pic, e->irqchip.pin, irq_source_id, level);
34 }
35 
36 static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
37 			      struct kvm *kvm, int irq_source_id, int level,
38 			      bool line_status)
39 {
40 	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
41 	return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, irq_source_id, level,
42 				line_status);
43 }
44 
45 int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
46 		struct kvm_lapic_irq *irq, struct dest_map *dest_map)
47 {
48 	int i, r = -1;
49 	struct kvm_vcpu *vcpu, *lowest = NULL;
50 	unsigned long dest_vcpu_bitmap[BITS_TO_LONGS(KVM_MAX_VCPUS)];
51 	unsigned int dest_vcpus = 0;
52 
53 	if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
54 		return r;
55 
56 	if (irq->dest_mode == APIC_DEST_PHYSICAL &&
57 	    irq->dest_id == 0xff && kvm_lowest_prio_delivery(irq)) {
58 		printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
59 		irq->delivery_mode = APIC_DM_FIXED;
60 	}
61 
62 	memset(dest_vcpu_bitmap, 0, sizeof(dest_vcpu_bitmap));
63 
64 	kvm_for_each_vcpu(i, vcpu, kvm) {
65 		if (!kvm_apic_present(vcpu))
66 			continue;
67 
68 		if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
69 					irq->dest_id, irq->dest_mode))
70 			continue;
71 
72 		if (!kvm_lowest_prio_delivery(irq)) {
73 			if (r < 0)
74 				r = 0;
75 			r += kvm_apic_set_irq(vcpu, irq, dest_map);
76 		} else if (kvm_apic_sw_enabled(vcpu->arch.apic)) {
77 			if (!kvm_vector_hashing_enabled()) {
78 				if (!lowest)
79 					lowest = vcpu;
80 				else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
81 					lowest = vcpu;
82 			} else {
83 				__set_bit(i, dest_vcpu_bitmap);
84 				dest_vcpus++;
85 			}
86 		}
87 	}
88 
89 	if (dest_vcpus != 0) {
90 		int idx = kvm_vector_to_index(irq->vector, dest_vcpus,
91 					dest_vcpu_bitmap, KVM_MAX_VCPUS);
92 
93 		lowest = kvm_get_vcpu(kvm, idx);
94 	}
95 
96 	if (lowest)
97 		r = kvm_apic_set_irq(lowest, irq, dest_map);
98 
99 	return r;
100 }
101 
102 void kvm_set_msi_irq(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *e,
103 		     struct kvm_lapic_irq *irq)
104 {
105 	struct msi_msg msg = { .address_lo = e->msi.address_lo,
106 			       .address_hi = e->msi.address_hi,
107 			       .data = e->msi.data };
108 
109 	trace_kvm_msi_set_irq(msg.address_lo | (kvm->arch.x2apic_format ?
110 			      (u64)msg.address_hi << 32 : 0), msg.data);
111 
112 	irq->dest_id = x86_msi_msg_get_destid(&msg, kvm->arch.x2apic_format);
113 	irq->vector = msg.arch_data.vector;
114 	irq->dest_mode = kvm_lapic_irq_dest_mode(msg.arch_addr_lo.dest_mode_logical);
115 	irq->trig_mode = msg.arch_data.is_level;
116 	irq->delivery_mode = msg.arch_data.delivery_mode << 8;
117 	irq->msi_redir_hint = msg.arch_addr_lo.redirect_hint;
118 	irq->level = 1;
119 	irq->shorthand = APIC_DEST_NOSHORT;
120 }
121 EXPORT_SYMBOL_GPL(kvm_set_msi_irq);
122 
123 static inline bool kvm_msi_route_invalid(struct kvm *kvm,
124 		struct kvm_kernel_irq_routing_entry *e)
125 {
126 	return kvm->arch.x2apic_format && (e->msi.address_hi & 0xff);
127 }
128 
129 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
130 		struct kvm *kvm, int irq_source_id, int level, bool line_status)
131 {
132 	struct kvm_lapic_irq irq;
133 
134 	if (kvm_msi_route_invalid(kvm, e))
135 		return -EINVAL;
136 
137 	if (!level)
138 		return -1;
139 
140 	kvm_set_msi_irq(kvm, e, &irq);
141 
142 	return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
143 }
144 
145 
146 static int kvm_hv_set_sint(struct kvm_kernel_irq_routing_entry *e,
147 		    struct kvm *kvm, int irq_source_id, int level,
148 		    bool line_status)
149 {
150 	if (!level)
151 		return -1;
152 
153 	return kvm_hv_synic_set_irq(kvm, e->hv_sint.vcpu, e->hv_sint.sint);
154 }
155 
156 int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
157 			      struct kvm *kvm, int irq_source_id, int level,
158 			      bool line_status)
159 {
160 	struct kvm_lapic_irq irq;
161 	int r;
162 
163 	switch (e->type) {
164 	case KVM_IRQ_ROUTING_HV_SINT:
165 		return kvm_hv_set_sint(e, kvm, irq_source_id, level,
166 				       line_status);
167 
168 	case KVM_IRQ_ROUTING_MSI:
169 		if (kvm_msi_route_invalid(kvm, e))
170 			return -EINVAL;
171 
172 		kvm_set_msi_irq(kvm, e, &irq);
173 
174 		if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
175 			return r;
176 		break;
177 
178 	default:
179 		break;
180 	}
181 
182 	return -EWOULDBLOCK;
183 }
184 
185 int kvm_request_irq_source_id(struct kvm *kvm)
186 {
187 	unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
188 	int irq_source_id;
189 
190 	mutex_lock(&kvm->irq_lock);
191 	irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
192 
193 	if (irq_source_id >= BITS_PER_LONG) {
194 		printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
195 		irq_source_id = -EFAULT;
196 		goto unlock;
197 	}
198 
199 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
200 	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
201 	set_bit(irq_source_id, bitmap);
202 unlock:
203 	mutex_unlock(&kvm->irq_lock);
204 
205 	return irq_source_id;
206 }
207 
208 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
209 {
210 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
211 	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
212 
213 	mutex_lock(&kvm->irq_lock);
214 	if (irq_source_id < 0 ||
215 	    irq_source_id >= BITS_PER_LONG) {
216 		printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
217 		goto unlock;
218 	}
219 	clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
220 	if (!irqchip_kernel(kvm))
221 		goto unlock;
222 
223 	kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
224 	kvm_pic_clear_all(kvm->arch.vpic, irq_source_id);
225 unlock:
226 	mutex_unlock(&kvm->irq_lock);
227 }
228 
229 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
230 				    struct kvm_irq_mask_notifier *kimn)
231 {
232 	mutex_lock(&kvm->irq_lock);
233 	kimn->irq = irq;
234 	hlist_add_head_rcu(&kimn->link, &kvm->arch.mask_notifier_list);
235 	mutex_unlock(&kvm->irq_lock);
236 }
237 
238 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
239 				      struct kvm_irq_mask_notifier *kimn)
240 {
241 	mutex_lock(&kvm->irq_lock);
242 	hlist_del_rcu(&kimn->link);
243 	mutex_unlock(&kvm->irq_lock);
244 	synchronize_srcu(&kvm->irq_srcu);
245 }
246 
247 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
248 			     bool mask)
249 {
250 	struct kvm_irq_mask_notifier *kimn;
251 	int idx, gsi;
252 
253 	idx = srcu_read_lock(&kvm->irq_srcu);
254 	gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
255 	if (gsi != -1)
256 		hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
257 			if (kimn->irq == gsi)
258 				kimn->func(kimn, mask);
259 	srcu_read_unlock(&kvm->irq_srcu, idx);
260 }
261 
262 bool kvm_arch_can_set_irq_routing(struct kvm *kvm)
263 {
264 	return irqchip_in_kernel(kvm);
265 }
266 
267 int kvm_set_routing_entry(struct kvm *kvm,
268 			  struct kvm_kernel_irq_routing_entry *e,
269 			  const struct kvm_irq_routing_entry *ue)
270 {
271 	/* We can't check irqchip_in_kernel() here as some callers are
272 	 * currently initializing the irqchip. Other callers should therefore
273 	 * check kvm_arch_can_set_irq_routing() before calling this function.
274 	 */
275 	switch (ue->type) {
276 	case KVM_IRQ_ROUTING_IRQCHIP:
277 		if (irqchip_split(kvm))
278 			return -EINVAL;
279 		e->irqchip.pin = ue->u.irqchip.pin;
280 		switch (ue->u.irqchip.irqchip) {
281 		case KVM_IRQCHIP_PIC_SLAVE:
282 			e->irqchip.pin += PIC_NUM_PINS / 2;
283 			fallthrough;
284 		case KVM_IRQCHIP_PIC_MASTER:
285 			if (ue->u.irqchip.pin >= PIC_NUM_PINS / 2)
286 				return -EINVAL;
287 			e->set = kvm_set_pic_irq;
288 			break;
289 		case KVM_IRQCHIP_IOAPIC:
290 			if (ue->u.irqchip.pin >= KVM_IOAPIC_NUM_PINS)
291 				return -EINVAL;
292 			e->set = kvm_set_ioapic_irq;
293 			break;
294 		default:
295 			return -EINVAL;
296 		}
297 		e->irqchip.irqchip = ue->u.irqchip.irqchip;
298 		break;
299 	case KVM_IRQ_ROUTING_MSI:
300 		e->set = kvm_set_msi;
301 		e->msi.address_lo = ue->u.msi.address_lo;
302 		e->msi.address_hi = ue->u.msi.address_hi;
303 		e->msi.data = ue->u.msi.data;
304 
305 		if (kvm_msi_route_invalid(kvm, e))
306 			return -EINVAL;
307 		break;
308 	case KVM_IRQ_ROUTING_HV_SINT:
309 		e->set = kvm_hv_set_sint;
310 		e->hv_sint.vcpu = ue->u.hv_sint.vcpu;
311 		e->hv_sint.sint = ue->u.hv_sint.sint;
312 		break;
313 	default:
314 		return -EINVAL;
315 	}
316 
317 	return 0;
318 }
319 
320 bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
321 			     struct kvm_vcpu **dest_vcpu)
322 {
323 	int i, r = 0;
324 	struct kvm_vcpu *vcpu;
325 
326 	if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
327 		return true;
328 
329 	kvm_for_each_vcpu(i, vcpu, kvm) {
330 		if (!kvm_apic_present(vcpu))
331 			continue;
332 
333 		if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand,
334 					irq->dest_id, irq->dest_mode))
335 			continue;
336 
337 		if (++r == 2)
338 			return false;
339 
340 		*dest_vcpu = vcpu;
341 	}
342 
343 	return r == 1;
344 }
345 EXPORT_SYMBOL_GPL(kvm_intr_is_single_vcpu);
346 
347 #define IOAPIC_ROUTING_ENTRY(irq) \
348 	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
349 	  .u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
350 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
351 
352 #define PIC_ROUTING_ENTRY(irq) \
353 	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
354 	  .u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
355 #define ROUTING_ENTRY2(irq) \
356 	IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
357 
358 static const struct kvm_irq_routing_entry default_routing[] = {
359 	ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
360 	ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
361 	ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
362 	ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
363 	ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
364 	ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
365 	ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
366 	ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
367 	ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
368 	ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
369 	ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
370 	ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
371 };
372 
373 int kvm_setup_default_irq_routing(struct kvm *kvm)
374 {
375 	return kvm_set_irq_routing(kvm, default_routing,
376 				   ARRAY_SIZE(default_routing), 0);
377 }
378 
379 static const struct kvm_irq_routing_entry empty_routing[] = {};
380 
381 int kvm_setup_empty_irq_routing(struct kvm *kvm)
382 {
383 	return kvm_set_irq_routing(kvm, empty_routing, 0, 0);
384 }
385 
386 void kvm_arch_post_irq_routing_update(struct kvm *kvm)
387 {
388 	if (!irqchip_split(kvm))
389 		return;
390 	kvm_make_scan_ioapic_request(kvm);
391 }
392 
393 void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu,
394 			    ulong *ioapic_handled_vectors)
395 {
396 	struct kvm *kvm = vcpu->kvm;
397 	struct kvm_kernel_irq_routing_entry *entry;
398 	struct kvm_irq_routing_table *table;
399 	u32 i, nr_ioapic_pins;
400 	int idx;
401 
402 	idx = srcu_read_lock(&kvm->irq_srcu);
403 	table = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
404 	nr_ioapic_pins = min_t(u32, table->nr_rt_entries,
405 			       kvm->arch.nr_reserved_ioapic_pins);
406 	for (i = 0; i < nr_ioapic_pins; ++i) {
407 		hlist_for_each_entry(entry, &table->map[i], link) {
408 			struct kvm_lapic_irq irq;
409 
410 			if (entry->type != KVM_IRQ_ROUTING_MSI)
411 				continue;
412 
413 			kvm_set_msi_irq(vcpu->kvm, entry, &irq);
414 
415 			if (irq.trig_mode &&
416 			    kvm_apic_match_dest(vcpu, NULL, APIC_DEST_NOSHORT,
417 						irq.dest_id, irq.dest_mode))
418 				__set_bit(irq.vector, ioapic_handled_vectors);
419 		}
420 	}
421 	srcu_read_unlock(&kvm->irq_srcu, idx);
422 }
423 
424 void kvm_arch_irq_routing_update(struct kvm *kvm)
425 {
426 	kvm_hv_irq_routing_update(kvm);
427 }
428