xref: /openbmc/linux/arch/x86/kvm/irq_comm.c (revision 5da094ac)
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 
13 #include <linux/kvm_host.h>
14 #include <linux/slab.h>
15 #include <linux/export.h>
16 #include <linux/rculist.h>
17 
18 #include <trace/events/kvm.h>
19 
20 #include "irq.h"
21 
22 #include "ioapic.h"
23 
24 #include "lapic.h"
25 
26 #include "hyperv.h"
27 #include "x86.h"
28 #include "xen.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 r = -1;
51 	struct kvm_vcpu *vcpu, *lowest = NULL;
52 	unsigned long i, 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 		pr_info("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 	struct msi_msg msg = { .address_lo = e->msi.address_lo,
108 			       .address_hi = e->msi.address_hi,
109 			       .data = e->msi.data };
110 
111 	trace_kvm_msi_set_irq(msg.address_lo | (kvm->arch.x2apic_format ?
112 			      (u64)msg.address_hi << 32 : 0), msg.data);
113 
114 	irq->dest_id = x86_msi_msg_get_destid(&msg, kvm->arch.x2apic_format);
115 	irq->vector = msg.arch_data.vector;
116 	irq->dest_mode = kvm_lapic_irq_dest_mode(msg.arch_addr_lo.dest_mode_logical);
117 	irq->trig_mode = msg.arch_data.is_level;
118 	irq->delivery_mode = msg.arch_data.delivery_mode << 8;
119 	irq->msi_redir_hint = msg.arch_addr_lo.redirect_hint;
120 	irq->level = 1;
121 	irq->shorthand = APIC_DEST_NOSHORT;
122 }
123 EXPORT_SYMBOL_GPL(kvm_set_msi_irq);
124 
125 static inline bool kvm_msi_route_invalid(struct kvm *kvm,
126 		struct kvm_kernel_irq_routing_entry *e)
127 {
128 	return kvm->arch.x2apic_format && (e->msi.address_hi & 0xff);
129 }
130 
131 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
132 		struct kvm *kvm, int irq_source_id, int level, bool line_status)
133 {
134 	struct kvm_lapic_irq irq;
135 
136 	if (kvm_msi_route_invalid(kvm, e))
137 		return -EINVAL;
138 
139 	if (!level)
140 		return -1;
141 
142 	kvm_set_msi_irq(kvm, e, &irq);
143 
144 	return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
145 }
146 
147 
148 static int kvm_hv_set_sint(struct kvm_kernel_irq_routing_entry *e,
149 		    struct kvm *kvm, int irq_source_id, int level,
150 		    bool line_status)
151 {
152 	if (!level)
153 		return -1;
154 
155 	return kvm_hv_synic_set_irq(kvm, e->hv_sint.vcpu, e->hv_sint.sint);
156 }
157 
158 int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
159 			      struct kvm *kvm, int irq_source_id, int level,
160 			      bool line_status)
161 {
162 	struct kvm_lapic_irq irq;
163 	int r;
164 
165 	switch (e->type) {
166 	case KVM_IRQ_ROUTING_HV_SINT:
167 		return kvm_hv_set_sint(e, kvm, irq_source_id, level,
168 				       line_status);
169 
170 	case KVM_IRQ_ROUTING_MSI:
171 		if (kvm_msi_route_invalid(kvm, e))
172 			return -EINVAL;
173 
174 		kvm_set_msi_irq(kvm, e, &irq);
175 
176 		if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
177 			return r;
178 		break;
179 
180 #ifdef CONFIG_KVM_XEN
181 	case KVM_IRQ_ROUTING_XEN_EVTCHN:
182 		if (!level)
183 			return -1;
184 
185 		return kvm_xen_set_evtchn_fast(&e->xen_evtchn, kvm);
186 #endif
187 	default:
188 		break;
189 	}
190 
191 	return -EWOULDBLOCK;
192 }
193 
194 int kvm_request_irq_source_id(struct kvm *kvm)
195 {
196 	unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
197 	int irq_source_id;
198 
199 	mutex_lock(&kvm->irq_lock);
200 	irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
201 
202 	if (irq_source_id >= BITS_PER_LONG) {
203 		pr_warn("exhausted allocatable IRQ sources!\n");
204 		irq_source_id = -EFAULT;
205 		goto unlock;
206 	}
207 
208 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
209 	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
210 	set_bit(irq_source_id, bitmap);
211 unlock:
212 	mutex_unlock(&kvm->irq_lock);
213 
214 	return irq_source_id;
215 }
216 
217 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
218 {
219 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
220 	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
221 
222 	mutex_lock(&kvm->irq_lock);
223 	if (irq_source_id < 0 ||
224 	    irq_source_id >= BITS_PER_LONG) {
225 		pr_err("IRQ source ID out of range!\n");
226 		goto unlock;
227 	}
228 	clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
229 	if (!irqchip_kernel(kvm))
230 		goto unlock;
231 
232 	kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
233 	kvm_pic_clear_all(kvm->arch.vpic, irq_source_id);
234 unlock:
235 	mutex_unlock(&kvm->irq_lock);
236 }
237 
238 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
239 				    struct kvm_irq_mask_notifier *kimn)
240 {
241 	mutex_lock(&kvm->irq_lock);
242 	kimn->irq = irq;
243 	hlist_add_head_rcu(&kimn->link, &kvm->arch.mask_notifier_list);
244 	mutex_unlock(&kvm->irq_lock);
245 }
246 
247 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
248 				      struct kvm_irq_mask_notifier *kimn)
249 {
250 	mutex_lock(&kvm->irq_lock);
251 	hlist_del_rcu(&kimn->link);
252 	mutex_unlock(&kvm->irq_lock);
253 	synchronize_srcu(&kvm->irq_srcu);
254 }
255 
256 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
257 			     bool mask)
258 {
259 	struct kvm_irq_mask_notifier *kimn;
260 	int idx, gsi;
261 
262 	idx = srcu_read_lock(&kvm->irq_srcu);
263 	gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
264 	if (gsi != -1)
265 		hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
266 			if (kimn->irq == gsi)
267 				kimn->func(kimn, mask);
268 	srcu_read_unlock(&kvm->irq_srcu, idx);
269 }
270 
271 bool kvm_arch_can_set_irq_routing(struct kvm *kvm)
272 {
273 	return irqchip_in_kernel(kvm);
274 }
275 
276 int kvm_set_routing_entry(struct kvm *kvm,
277 			  struct kvm_kernel_irq_routing_entry *e,
278 			  const struct kvm_irq_routing_entry *ue)
279 {
280 	/* We can't check irqchip_in_kernel() here as some callers are
281 	 * currently initializing the irqchip. Other callers should therefore
282 	 * check kvm_arch_can_set_irq_routing() before calling this function.
283 	 */
284 	switch (ue->type) {
285 	case KVM_IRQ_ROUTING_IRQCHIP:
286 		if (irqchip_split(kvm))
287 			return -EINVAL;
288 		e->irqchip.pin = ue->u.irqchip.pin;
289 		switch (ue->u.irqchip.irqchip) {
290 		case KVM_IRQCHIP_PIC_SLAVE:
291 			e->irqchip.pin += PIC_NUM_PINS / 2;
292 			fallthrough;
293 		case KVM_IRQCHIP_PIC_MASTER:
294 			if (ue->u.irqchip.pin >= PIC_NUM_PINS / 2)
295 				return -EINVAL;
296 			e->set = kvm_set_pic_irq;
297 			break;
298 		case KVM_IRQCHIP_IOAPIC:
299 			if (ue->u.irqchip.pin >= KVM_IOAPIC_NUM_PINS)
300 				return -EINVAL;
301 			e->set = kvm_set_ioapic_irq;
302 			break;
303 		default:
304 			return -EINVAL;
305 		}
306 		e->irqchip.irqchip = ue->u.irqchip.irqchip;
307 		break;
308 	case KVM_IRQ_ROUTING_MSI:
309 		e->set = kvm_set_msi;
310 		e->msi.address_lo = ue->u.msi.address_lo;
311 		e->msi.address_hi = ue->u.msi.address_hi;
312 		e->msi.data = ue->u.msi.data;
313 
314 		if (kvm_msi_route_invalid(kvm, e))
315 			return -EINVAL;
316 		break;
317 	case KVM_IRQ_ROUTING_HV_SINT:
318 		e->set = kvm_hv_set_sint;
319 		e->hv_sint.vcpu = ue->u.hv_sint.vcpu;
320 		e->hv_sint.sint = ue->u.hv_sint.sint;
321 		break;
322 #ifdef CONFIG_KVM_XEN
323 	case KVM_IRQ_ROUTING_XEN_EVTCHN:
324 		return kvm_xen_setup_evtchn(kvm, e, ue);
325 #endif
326 	default:
327 		return -EINVAL;
328 	}
329 
330 	return 0;
331 }
332 
333 bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
334 			     struct kvm_vcpu **dest_vcpu)
335 {
336 	int r = 0;
337 	unsigned long i;
338 	struct kvm_vcpu *vcpu;
339 
340 	if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
341 		return true;
342 
343 	kvm_for_each_vcpu(i, vcpu, kvm) {
344 		if (!kvm_apic_present(vcpu))
345 			continue;
346 
347 		if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand,
348 					irq->dest_id, irq->dest_mode))
349 			continue;
350 
351 		if (++r == 2)
352 			return false;
353 
354 		*dest_vcpu = vcpu;
355 	}
356 
357 	return r == 1;
358 }
359 EXPORT_SYMBOL_GPL(kvm_intr_is_single_vcpu);
360 
361 #define IOAPIC_ROUTING_ENTRY(irq) \
362 	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
363 	  .u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
364 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
365 
366 #define PIC_ROUTING_ENTRY(irq) \
367 	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
368 	  .u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
369 #define ROUTING_ENTRY2(irq) \
370 	IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
371 
372 static const struct kvm_irq_routing_entry default_routing[] = {
373 	ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
374 	ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
375 	ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
376 	ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
377 	ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
378 	ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
379 	ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
380 	ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
381 	ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
382 	ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
383 	ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
384 	ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
385 };
386 
387 int kvm_setup_default_irq_routing(struct kvm *kvm)
388 {
389 	return kvm_set_irq_routing(kvm, default_routing,
390 				   ARRAY_SIZE(default_routing), 0);
391 }
392 
393 static const struct kvm_irq_routing_entry empty_routing[] = {};
394 
395 int kvm_setup_empty_irq_routing(struct kvm *kvm)
396 {
397 	return kvm_set_irq_routing(kvm, empty_routing, 0, 0);
398 }
399 
400 void kvm_arch_post_irq_routing_update(struct kvm *kvm)
401 {
402 	if (!irqchip_split(kvm))
403 		return;
404 	kvm_make_scan_ioapic_request(kvm);
405 }
406 
407 void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu,
408 			    ulong *ioapic_handled_vectors)
409 {
410 	struct kvm *kvm = vcpu->kvm;
411 	struct kvm_kernel_irq_routing_entry *entry;
412 	struct kvm_irq_routing_table *table;
413 	u32 i, nr_ioapic_pins;
414 	int idx;
415 
416 	idx = srcu_read_lock(&kvm->irq_srcu);
417 	table = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
418 	nr_ioapic_pins = min_t(u32, table->nr_rt_entries,
419 			       kvm->arch.nr_reserved_ioapic_pins);
420 	for (i = 0; i < nr_ioapic_pins; ++i) {
421 		hlist_for_each_entry(entry, &table->map[i], link) {
422 			struct kvm_lapic_irq irq;
423 
424 			if (entry->type != KVM_IRQ_ROUTING_MSI)
425 				continue;
426 
427 			kvm_set_msi_irq(vcpu->kvm, entry, &irq);
428 
429 			if (irq.trig_mode &&
430 			    (kvm_apic_match_dest(vcpu, NULL, APIC_DEST_NOSHORT,
431 						 irq.dest_id, irq.dest_mode) ||
432 			     kvm_apic_pending_eoi(vcpu, irq.vector)))
433 				__set_bit(irq.vector, ioapic_handled_vectors);
434 		}
435 	}
436 	srcu_read_unlock(&kvm->irq_srcu, idx);
437 }
438 
439 void kvm_arch_irq_routing_update(struct kvm *kvm)
440 {
441 	kvm_hv_irq_routing_update(kvm);
442 }
443