xref: /openbmc/linux/arch/x86/kvm/irq_comm.c (revision 62a9bbf2)
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 #include "xen.h"
28 
29 static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
30 			   struct kvm *kvm, int irq_source_id, int level,
31 			   bool line_status)
32 {
33 	struct kvm_pic *pic = kvm->arch.vpic;
34 	return kvm_pic_set_irq(pic, e->irqchip.pin, irq_source_id, level);
35 }
36 
37 static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
38 			      struct kvm *kvm, int irq_source_id, int level,
39 			      bool line_status)
40 {
41 	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
42 	return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, irq_source_id, level,
43 				line_status);
44 }
45 
46 int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
47 		struct kvm_lapic_irq *irq, struct dest_map *dest_map)
48 {
49 	int r = -1;
50 	struct kvm_vcpu *vcpu, *lowest = NULL;
51 	unsigned long i, dest_vcpu_bitmap[BITS_TO_LONGS(KVM_MAX_VCPUS)];
52 	unsigned int dest_vcpus = 0;
53 
54 	if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
55 		return r;
56 
57 	if (irq->dest_mode == APIC_DEST_PHYSICAL &&
58 	    irq->dest_id == 0xff && kvm_lowest_prio_delivery(irq)) {
59 		printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
60 		irq->delivery_mode = APIC_DM_FIXED;
61 	}
62 
63 	memset(dest_vcpu_bitmap, 0, sizeof(dest_vcpu_bitmap));
64 
65 	kvm_for_each_vcpu(i, vcpu, kvm) {
66 		if (!kvm_apic_present(vcpu))
67 			continue;
68 
69 		if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
70 					irq->dest_id, irq->dest_mode))
71 			continue;
72 
73 		if (!kvm_lowest_prio_delivery(irq)) {
74 			if (r < 0)
75 				r = 0;
76 			r += kvm_apic_set_irq(vcpu, irq, dest_map);
77 		} else if (kvm_apic_sw_enabled(vcpu->arch.apic)) {
78 			if (!kvm_vector_hashing_enabled()) {
79 				if (!lowest)
80 					lowest = vcpu;
81 				else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
82 					lowest = vcpu;
83 			} else {
84 				__set_bit(i, dest_vcpu_bitmap);
85 				dest_vcpus++;
86 			}
87 		}
88 	}
89 
90 	if (dest_vcpus != 0) {
91 		int idx = kvm_vector_to_index(irq->vector, dest_vcpus,
92 					dest_vcpu_bitmap, KVM_MAX_VCPUS);
93 
94 		lowest = kvm_get_vcpu(kvm, idx);
95 	}
96 
97 	if (lowest)
98 		r = kvm_apic_set_irq(lowest, irq, dest_map);
99 
100 	return r;
101 }
102 
103 void kvm_set_msi_irq(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *e,
104 		     struct kvm_lapic_irq *irq)
105 {
106 	struct msi_msg msg = { .address_lo = e->msi.address_lo,
107 			       .address_hi = e->msi.address_hi,
108 			       .data = e->msi.data };
109 
110 	trace_kvm_msi_set_irq(msg.address_lo | (kvm->arch.x2apic_format ?
111 			      (u64)msg.address_hi << 32 : 0), msg.data);
112 
113 	irq->dest_id = x86_msi_msg_get_destid(&msg, kvm->arch.x2apic_format);
114 	irq->vector = msg.arch_data.vector;
115 	irq->dest_mode = kvm_lapic_irq_dest_mode(msg.arch_addr_lo.dest_mode_logical);
116 	irq->trig_mode = msg.arch_data.is_level;
117 	irq->delivery_mode = msg.arch_data.delivery_mode << 8;
118 	irq->msi_redir_hint = msg.arch_addr_lo.redirect_hint;
119 	irq->level = 1;
120 	irq->shorthand = APIC_DEST_NOSHORT;
121 }
122 EXPORT_SYMBOL_GPL(kvm_set_msi_irq);
123 
124 static inline bool kvm_msi_route_invalid(struct kvm *kvm,
125 		struct kvm_kernel_irq_routing_entry *e)
126 {
127 	return kvm->arch.x2apic_format && (e->msi.address_hi & 0xff);
128 }
129 
130 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
131 		struct kvm *kvm, int irq_source_id, int level, bool line_status)
132 {
133 	struct kvm_lapic_irq irq;
134 
135 	if (kvm_msi_route_invalid(kvm, e))
136 		return -EINVAL;
137 
138 	if (!level)
139 		return -1;
140 
141 	kvm_set_msi_irq(kvm, e, &irq);
142 
143 	return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
144 }
145 
146 
147 static int kvm_hv_set_sint(struct kvm_kernel_irq_routing_entry *e,
148 		    struct kvm *kvm, int irq_source_id, int level,
149 		    bool line_status)
150 {
151 	if (!level)
152 		return -1;
153 
154 	return kvm_hv_synic_set_irq(kvm, e->hv_sint.vcpu, e->hv_sint.sint);
155 }
156 
157 int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
158 			      struct kvm *kvm, int irq_source_id, int level,
159 			      bool line_status)
160 {
161 	struct kvm_lapic_irq irq;
162 	int r;
163 
164 	switch (e->type) {
165 	case KVM_IRQ_ROUTING_HV_SINT:
166 		return kvm_hv_set_sint(e, kvm, irq_source_id, level,
167 				       line_status);
168 
169 	case KVM_IRQ_ROUTING_MSI:
170 		if (kvm_msi_route_invalid(kvm, e))
171 			return -EINVAL;
172 
173 		kvm_set_msi_irq(kvm, e, &irq);
174 
175 		if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
176 			return r;
177 		break;
178 
179 #ifdef CONFIG_KVM_XEN
180 	case KVM_IRQ_ROUTING_XEN_EVTCHN:
181 		if (!level)
182 			return -1;
183 
184 		return kvm_xen_set_evtchn_fast(&e->xen_evtchn, kvm);
185 #endif
186 	default:
187 		break;
188 	}
189 
190 	return -EWOULDBLOCK;
191 }
192 
193 int kvm_request_irq_source_id(struct kvm *kvm)
194 {
195 	unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
196 	int irq_source_id;
197 
198 	mutex_lock(&kvm->irq_lock);
199 	irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
200 
201 	if (irq_source_id >= BITS_PER_LONG) {
202 		printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
203 		irq_source_id = -EFAULT;
204 		goto unlock;
205 	}
206 
207 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
208 	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
209 	set_bit(irq_source_id, bitmap);
210 unlock:
211 	mutex_unlock(&kvm->irq_lock);
212 
213 	return irq_source_id;
214 }
215 
216 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
217 {
218 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
219 	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
220 
221 	mutex_lock(&kvm->irq_lock);
222 	if (irq_source_id < 0 ||
223 	    irq_source_id >= BITS_PER_LONG) {
224 		printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
225 		goto unlock;
226 	}
227 	clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
228 	if (!irqchip_kernel(kvm))
229 		goto unlock;
230 
231 	kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
232 	kvm_pic_clear_all(kvm->arch.vpic, irq_source_id);
233 unlock:
234 	mutex_unlock(&kvm->irq_lock);
235 }
236 
237 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
238 				    struct kvm_irq_mask_notifier *kimn)
239 {
240 	mutex_lock(&kvm->irq_lock);
241 	kimn->irq = irq;
242 	hlist_add_head_rcu(&kimn->link, &kvm->arch.mask_notifier_list);
243 	mutex_unlock(&kvm->irq_lock);
244 }
245 
246 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
247 				      struct kvm_irq_mask_notifier *kimn)
248 {
249 	mutex_lock(&kvm->irq_lock);
250 	hlist_del_rcu(&kimn->link);
251 	mutex_unlock(&kvm->irq_lock);
252 	synchronize_srcu(&kvm->irq_srcu);
253 }
254 
255 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
256 			     bool mask)
257 {
258 	struct kvm_irq_mask_notifier *kimn;
259 	int idx, gsi;
260 
261 	idx = srcu_read_lock(&kvm->irq_srcu);
262 	gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
263 	if (gsi != -1)
264 		hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
265 			if (kimn->irq == gsi)
266 				kimn->func(kimn, mask);
267 	srcu_read_unlock(&kvm->irq_srcu, idx);
268 }
269 
270 bool kvm_arch_can_set_irq_routing(struct kvm *kvm)
271 {
272 	return irqchip_in_kernel(kvm);
273 }
274 
275 int kvm_set_routing_entry(struct kvm *kvm,
276 			  struct kvm_kernel_irq_routing_entry *e,
277 			  const struct kvm_irq_routing_entry *ue)
278 {
279 	/* We can't check irqchip_in_kernel() here as some callers are
280 	 * currently initializing the irqchip. Other callers should therefore
281 	 * check kvm_arch_can_set_irq_routing() before calling this function.
282 	 */
283 	switch (ue->type) {
284 	case KVM_IRQ_ROUTING_IRQCHIP:
285 		if (irqchip_split(kvm))
286 			return -EINVAL;
287 		e->irqchip.pin = ue->u.irqchip.pin;
288 		switch (ue->u.irqchip.irqchip) {
289 		case KVM_IRQCHIP_PIC_SLAVE:
290 			e->irqchip.pin += PIC_NUM_PINS / 2;
291 			fallthrough;
292 		case KVM_IRQCHIP_PIC_MASTER:
293 			if (ue->u.irqchip.pin >= PIC_NUM_PINS / 2)
294 				return -EINVAL;
295 			e->set = kvm_set_pic_irq;
296 			break;
297 		case KVM_IRQCHIP_IOAPIC:
298 			if (ue->u.irqchip.pin >= KVM_IOAPIC_NUM_PINS)
299 				return -EINVAL;
300 			e->set = kvm_set_ioapic_irq;
301 			break;
302 		default:
303 			return -EINVAL;
304 		}
305 		e->irqchip.irqchip = ue->u.irqchip.irqchip;
306 		break;
307 	case KVM_IRQ_ROUTING_MSI:
308 		e->set = kvm_set_msi;
309 		e->msi.address_lo = ue->u.msi.address_lo;
310 		e->msi.address_hi = ue->u.msi.address_hi;
311 		e->msi.data = ue->u.msi.data;
312 
313 		if (kvm_msi_route_invalid(kvm, e))
314 			return -EINVAL;
315 		break;
316 	case KVM_IRQ_ROUTING_HV_SINT:
317 		e->set = kvm_hv_set_sint;
318 		e->hv_sint.vcpu = ue->u.hv_sint.vcpu;
319 		e->hv_sint.sint = ue->u.hv_sint.sint;
320 		break;
321 #ifdef CONFIG_KVM_XEN
322 	case KVM_IRQ_ROUTING_XEN_EVTCHN:
323 		return kvm_xen_setup_evtchn(kvm, e, ue);
324 #endif
325 	default:
326 		return -EINVAL;
327 	}
328 
329 	return 0;
330 }
331 
332 bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
333 			     struct kvm_vcpu **dest_vcpu)
334 {
335 	int r = 0;
336 	unsigned long i;
337 	struct kvm_vcpu *vcpu;
338 
339 	if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
340 		return true;
341 
342 	kvm_for_each_vcpu(i, vcpu, kvm) {
343 		if (!kvm_apic_present(vcpu))
344 			continue;
345 
346 		if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand,
347 					irq->dest_id, irq->dest_mode))
348 			continue;
349 
350 		if (++r == 2)
351 			return false;
352 
353 		*dest_vcpu = vcpu;
354 	}
355 
356 	return r == 1;
357 }
358 EXPORT_SYMBOL_GPL(kvm_intr_is_single_vcpu);
359 
360 #define IOAPIC_ROUTING_ENTRY(irq) \
361 	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
362 	  .u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
363 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
364 
365 #define PIC_ROUTING_ENTRY(irq) \
366 	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
367 	  .u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
368 #define ROUTING_ENTRY2(irq) \
369 	IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
370 
371 static const struct kvm_irq_routing_entry default_routing[] = {
372 	ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
373 	ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
374 	ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
375 	ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
376 	ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
377 	ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
378 	ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
379 	ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
380 	ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
381 	ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
382 	ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
383 	ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
384 };
385 
386 int kvm_setup_default_irq_routing(struct kvm *kvm)
387 {
388 	return kvm_set_irq_routing(kvm, default_routing,
389 				   ARRAY_SIZE(default_routing), 0);
390 }
391 
392 static const struct kvm_irq_routing_entry empty_routing[] = {};
393 
394 int kvm_setup_empty_irq_routing(struct kvm *kvm)
395 {
396 	return kvm_set_irq_routing(kvm, empty_routing, 0, 0);
397 }
398 
399 void kvm_arch_post_irq_routing_update(struct kvm *kvm)
400 {
401 	if (!irqchip_split(kvm))
402 		return;
403 	kvm_make_scan_ioapic_request(kvm);
404 }
405 
406 void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu,
407 			    ulong *ioapic_handled_vectors)
408 {
409 	struct kvm *kvm = vcpu->kvm;
410 	struct kvm_kernel_irq_routing_entry *entry;
411 	struct kvm_irq_routing_table *table;
412 	u32 i, nr_ioapic_pins;
413 	int idx;
414 
415 	idx = srcu_read_lock(&kvm->irq_srcu);
416 	table = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
417 	nr_ioapic_pins = min_t(u32, table->nr_rt_entries,
418 			       kvm->arch.nr_reserved_ioapic_pins);
419 	for (i = 0; i < nr_ioapic_pins; ++i) {
420 		hlist_for_each_entry(entry, &table->map[i], link) {
421 			struct kvm_lapic_irq irq;
422 
423 			if (entry->type != KVM_IRQ_ROUTING_MSI)
424 				continue;
425 
426 			kvm_set_msi_irq(vcpu->kvm, entry, &irq);
427 
428 			if (irq.trig_mode &&
429 			    (kvm_apic_match_dest(vcpu, NULL, APIC_DEST_NOSHORT,
430 						 irq.dest_id, irq.dest_mode) ||
431 			     kvm_apic_pending_eoi(vcpu, irq.vector)))
432 				__set_bit(irq.vector, ioapic_handled_vectors);
433 		}
434 	}
435 	srcu_read_unlock(&kvm->irq_srcu, idx);
436 }
437 
438 void kvm_arch_irq_routing_update(struct kvm *kvm)
439 {
440 	kvm_hv_irq_routing_update(kvm);
441 }
442