1 /*
2  * irq_comm.c: Common API for in kernel interrupt controller
3  * Copyright (c) 2007, Intel Corporation.
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along with
15  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
16  * Place - Suite 330, Boston, MA 02111-1307 USA.
17  * Authors:
18  *   Yaozu (Eddie) Dong <Eddie.dong@intel.com>
19  *
20  * Copyright 2010 Red Hat, Inc. and/or its affiliates.
21  */
22 
23 #include <linux/kvm_host.h>
24 #include <linux/slab.h>
25 #include <trace/events/kvm.h>
26 
27 #include <asm/msidef.h>
28 #ifdef CONFIG_IA64
29 #include <asm/iosapic.h>
30 #endif
31 
32 #include "irq.h"
33 
34 #include "ioapic.h"
35 
kvm_irq_line_state(unsigned long * irq_state,int irq_source_id,int level)36 static inline int kvm_irq_line_state(unsigned long *irq_state,
37 				     int irq_source_id, int level)
38 {
39 	/* Logical OR for level trig interrupt */
40 	if (level)
41 		set_bit(irq_source_id, irq_state);
42 	else
43 		clear_bit(irq_source_id, irq_state);
44 
45 	return !!(*irq_state);
46 }
47 
kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry * e,struct kvm * kvm,int irq_source_id,int level)48 static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
49 			   struct kvm *kvm, int irq_source_id, int level)
50 {
51 #ifdef CONFIG_X86
52 	struct kvm_pic *pic = pic_irqchip(kvm);
53 	level = kvm_irq_line_state(&pic->irq_states[e->irqchip.pin],
54 				   irq_source_id, level);
55 	return kvm_pic_set_irq(pic, e->irqchip.pin, level);
56 #else
57 	return -1;
58 #endif
59 }
60 
kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry * e,struct kvm * kvm,int irq_source_id,int level)61 static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
62 			      struct kvm *kvm, int irq_source_id, int level)
63 {
64 	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
65 	level = kvm_irq_line_state(&ioapic->irq_states[e->irqchip.pin],
66 				   irq_source_id, level);
67 
68 	return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, level);
69 }
70 
kvm_is_dm_lowest_prio(struct kvm_lapic_irq * irq)71 inline static bool kvm_is_dm_lowest_prio(struct kvm_lapic_irq *irq)
72 {
73 #ifdef CONFIG_IA64
74 	return irq->delivery_mode ==
75 		(IOSAPIC_LOWEST_PRIORITY << IOSAPIC_DELIVERY_SHIFT);
76 #else
77 	return irq->delivery_mode == APIC_DM_LOWEST;
78 #endif
79 }
80 
kvm_irq_delivery_to_apic(struct kvm * kvm,struct kvm_lapic * src,struct kvm_lapic_irq * irq)81 int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
82 		struct kvm_lapic_irq *irq)
83 {
84 	int i, r = -1;
85 	struct kvm_vcpu *vcpu, *lowest = NULL;
86 
87 	if (irq->dest_mode == 0 && irq->dest_id == 0xff &&
88 			kvm_is_dm_lowest_prio(irq))
89 		printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
90 
91 	kvm_for_each_vcpu(i, vcpu, kvm) {
92 		if (!kvm_apic_present(vcpu))
93 			continue;
94 
95 		if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
96 					irq->dest_id, irq->dest_mode))
97 			continue;
98 
99 		if (!kvm_is_dm_lowest_prio(irq)) {
100 			if (r < 0)
101 				r = 0;
102 			r += kvm_apic_set_irq(vcpu, irq);
103 		} else if (kvm_lapic_enabled(vcpu)) {
104 			if (!lowest)
105 				lowest = vcpu;
106 			else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
107 				lowest = vcpu;
108 		}
109 	}
110 
111 	if (lowest)
112 		r = kvm_apic_set_irq(lowest, irq);
113 
114 	return r;
115 }
116 
kvm_set_msi(struct kvm_kernel_irq_routing_entry * e,struct kvm * kvm,int irq_source_id,int level)117 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
118 		struct kvm *kvm, int irq_source_id, int level)
119 {
120 	struct kvm_lapic_irq irq;
121 
122 	if (!level)
123 		return -1;
124 
125 	trace_kvm_msi_set_irq(e->msi.address_lo, e->msi.data);
126 
127 	irq.dest_id = (e->msi.address_lo &
128 			MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
129 	irq.vector = (e->msi.data &
130 			MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
131 	irq.dest_mode = (1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo;
132 	irq.trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
133 	irq.delivery_mode = e->msi.data & 0x700;
134 	irq.level = 1;
135 	irq.shorthand = 0;
136 
137 	/* TODO Deal with RH bit of MSI message address */
138 	return kvm_irq_delivery_to_apic(kvm, NULL, &irq);
139 }
140 
141 /*
142  * Return value:
143  *  < 0   Interrupt was ignored (masked or not delivered for other reasons)
144  *  = 0   Interrupt was coalesced (previous irq is still pending)
145  *  > 0   Number of CPUs interrupt was delivered to
146  */
kvm_set_irq(struct kvm * kvm,int irq_source_id,u32 irq,int level)147 int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level)
148 {
149 	struct kvm_kernel_irq_routing_entry *e, irq_set[KVM_NR_IRQCHIPS];
150 	int ret = -1, i = 0;
151 	struct kvm_irq_routing_table *irq_rt;
152 	struct hlist_node *n;
153 
154 	trace_kvm_set_irq(irq, level, irq_source_id);
155 
156 	/* Not possible to detect if the guest uses the PIC or the
157 	 * IOAPIC.  So set the bit in both. The guest will ignore
158 	 * writes to the unused one.
159 	 */
160 	rcu_read_lock();
161 	irq_rt = rcu_dereference(kvm->irq_routing);
162 	if (irq < irq_rt->nr_rt_entries)
163 		hlist_for_each_entry(e, n, &irq_rt->map[irq], link)
164 			irq_set[i++] = *e;
165 	rcu_read_unlock();
166 
167 	while(i--) {
168 		int r;
169 		r = irq_set[i].set(&irq_set[i], kvm, irq_source_id, level);
170 		if (r < 0)
171 			continue;
172 
173 		ret = r + ((ret < 0) ? 0 : ret);
174 	}
175 
176 	return ret;
177 }
178 
kvm_notify_acked_irq(struct kvm * kvm,unsigned irqchip,unsigned pin)179 void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
180 {
181 	struct kvm_irq_ack_notifier *kian;
182 	struct hlist_node *n;
183 	int gsi;
184 
185 	trace_kvm_ack_irq(irqchip, pin);
186 
187 	rcu_read_lock();
188 	gsi = rcu_dereference(kvm->irq_routing)->chip[irqchip][pin];
189 	if (gsi != -1)
190 		hlist_for_each_entry_rcu(kian, n, &kvm->irq_ack_notifier_list,
191 					 link)
192 			if (kian->gsi == gsi)
193 				kian->irq_acked(kian);
194 	rcu_read_unlock();
195 }
196 
kvm_register_irq_ack_notifier(struct kvm * kvm,struct kvm_irq_ack_notifier * kian)197 void kvm_register_irq_ack_notifier(struct kvm *kvm,
198 				   struct kvm_irq_ack_notifier *kian)
199 {
200 	mutex_lock(&kvm->irq_lock);
201 	hlist_add_head_rcu(&kian->link, &kvm->irq_ack_notifier_list);
202 	mutex_unlock(&kvm->irq_lock);
203 }
204 
kvm_unregister_irq_ack_notifier(struct kvm * kvm,struct kvm_irq_ack_notifier * kian)205 void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
206 				    struct kvm_irq_ack_notifier *kian)
207 {
208 	mutex_lock(&kvm->irq_lock);
209 	hlist_del_init_rcu(&kian->link);
210 	mutex_unlock(&kvm->irq_lock);
211 	synchronize_rcu();
212 }
213 
kvm_request_irq_source_id(struct kvm * kvm)214 int kvm_request_irq_source_id(struct kvm *kvm)
215 {
216 	unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
217 	int irq_source_id;
218 
219 	mutex_lock(&kvm->irq_lock);
220 	irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
221 
222 	if (irq_source_id >= BITS_PER_LONG) {
223 		printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
224 		irq_source_id = -EFAULT;
225 		goto unlock;
226 	}
227 
228 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
229 	set_bit(irq_source_id, bitmap);
230 unlock:
231 	mutex_unlock(&kvm->irq_lock);
232 
233 	return irq_source_id;
234 }
235 
kvm_free_irq_source_id(struct kvm * kvm,int irq_source_id)236 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
237 {
238 	int i;
239 
240 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
241 
242 	mutex_lock(&kvm->irq_lock);
243 	if (irq_source_id < 0 ||
244 	    irq_source_id >= BITS_PER_LONG) {
245 		printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
246 		goto unlock;
247 	}
248 	clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
249 	if (!irqchip_in_kernel(kvm))
250 		goto unlock;
251 
252 	for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++) {
253 		clear_bit(irq_source_id, &kvm->arch.vioapic->irq_states[i]);
254 		if (i >= 16)
255 			continue;
256 #ifdef CONFIG_X86
257 		clear_bit(irq_source_id, &pic_irqchip(kvm)->irq_states[i]);
258 #endif
259 	}
260 unlock:
261 	mutex_unlock(&kvm->irq_lock);
262 }
263 
kvm_register_irq_mask_notifier(struct kvm * kvm,int irq,struct kvm_irq_mask_notifier * kimn)264 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
265 				    struct kvm_irq_mask_notifier *kimn)
266 {
267 	mutex_lock(&kvm->irq_lock);
268 	kimn->irq = irq;
269 	hlist_add_head_rcu(&kimn->link, &kvm->mask_notifier_list);
270 	mutex_unlock(&kvm->irq_lock);
271 }
272 
kvm_unregister_irq_mask_notifier(struct kvm * kvm,int irq,struct kvm_irq_mask_notifier * kimn)273 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
274 				      struct kvm_irq_mask_notifier *kimn)
275 {
276 	mutex_lock(&kvm->irq_lock);
277 	hlist_del_rcu(&kimn->link);
278 	mutex_unlock(&kvm->irq_lock);
279 	synchronize_rcu();
280 }
281 
kvm_fire_mask_notifiers(struct kvm * kvm,unsigned irqchip,unsigned pin,bool mask)282 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
283 			     bool mask)
284 {
285 	struct kvm_irq_mask_notifier *kimn;
286 	struct hlist_node *n;
287 	int gsi;
288 
289 	rcu_read_lock();
290 	gsi = rcu_dereference(kvm->irq_routing)->chip[irqchip][pin];
291 	if (gsi != -1)
292 		hlist_for_each_entry_rcu(kimn, n, &kvm->mask_notifier_list, link)
293 			if (kimn->irq == gsi)
294 				kimn->func(kimn, mask);
295 	rcu_read_unlock();
296 }
297 
kvm_free_irq_routing(struct kvm * kvm)298 void kvm_free_irq_routing(struct kvm *kvm)
299 {
300 	/* Called only during vm destruction. Nobody can use the pointer
301 	   at this stage */
302 	kfree(kvm->irq_routing);
303 }
304 
setup_routing_entry(struct kvm_irq_routing_table * rt,struct kvm_kernel_irq_routing_entry * e,const struct kvm_irq_routing_entry * ue)305 static int setup_routing_entry(struct kvm_irq_routing_table *rt,
306 			       struct kvm_kernel_irq_routing_entry *e,
307 			       const struct kvm_irq_routing_entry *ue)
308 {
309 	int r = -EINVAL;
310 	int delta;
311 	unsigned max_pin;
312 	struct kvm_kernel_irq_routing_entry *ei;
313 	struct hlist_node *n;
314 
315 	/*
316 	 * Do not allow GSI to be mapped to the same irqchip more than once.
317 	 * Allow only one to one mapping between GSI and MSI.
318 	 */
319 	hlist_for_each_entry(ei, n, &rt->map[ue->gsi], link)
320 		if (ei->type == KVM_IRQ_ROUTING_MSI ||
321 		    ue->type == KVM_IRQ_ROUTING_MSI ||
322 		    ue->u.irqchip.irqchip == ei->irqchip.irqchip)
323 			return r;
324 
325 	e->gsi = ue->gsi;
326 	e->type = ue->type;
327 	switch (ue->type) {
328 	case KVM_IRQ_ROUTING_IRQCHIP:
329 		delta = 0;
330 		switch (ue->u.irqchip.irqchip) {
331 		case KVM_IRQCHIP_PIC_MASTER:
332 			e->set = kvm_set_pic_irq;
333 			max_pin = 16;
334 			break;
335 		case KVM_IRQCHIP_PIC_SLAVE:
336 			e->set = kvm_set_pic_irq;
337 			max_pin = 16;
338 			delta = 8;
339 			break;
340 		case KVM_IRQCHIP_IOAPIC:
341 			max_pin = KVM_IOAPIC_NUM_PINS;
342 			e->set = kvm_set_ioapic_irq;
343 			break;
344 		default:
345 			goto out;
346 		}
347 		e->irqchip.irqchip = ue->u.irqchip.irqchip;
348 		e->irqchip.pin = ue->u.irqchip.pin + delta;
349 		if (e->irqchip.pin >= max_pin)
350 			goto out;
351 		rt->chip[ue->u.irqchip.irqchip][e->irqchip.pin] = ue->gsi;
352 		break;
353 	case KVM_IRQ_ROUTING_MSI:
354 		e->set = kvm_set_msi;
355 		e->msi.address_lo = ue->u.msi.address_lo;
356 		e->msi.address_hi = ue->u.msi.address_hi;
357 		e->msi.data = ue->u.msi.data;
358 		break;
359 	default:
360 		goto out;
361 	}
362 
363 	hlist_add_head(&e->link, &rt->map[e->gsi]);
364 	r = 0;
365 out:
366 	return r;
367 }
368 
369 
kvm_set_irq_routing(struct kvm * kvm,const struct kvm_irq_routing_entry * ue,unsigned nr,unsigned flags)370 int kvm_set_irq_routing(struct kvm *kvm,
371 			const struct kvm_irq_routing_entry *ue,
372 			unsigned nr,
373 			unsigned flags)
374 {
375 	struct kvm_irq_routing_table *new, *old;
376 	u32 i, j, nr_rt_entries = 0;
377 	int r;
378 
379 	for (i = 0; i < nr; ++i) {
380 		if (ue[i].gsi >= KVM_MAX_IRQ_ROUTES)
381 			return -EINVAL;
382 		nr_rt_entries = max(nr_rt_entries, ue[i].gsi);
383 	}
384 
385 	nr_rt_entries += 1;
386 
387 	new = kzalloc(sizeof(*new) + (nr_rt_entries * sizeof(struct hlist_head))
388 		      + (nr * sizeof(struct kvm_kernel_irq_routing_entry)),
389 		      GFP_KERNEL);
390 
391 	if (!new)
392 		return -ENOMEM;
393 
394 	new->rt_entries = (void *)&new->map[nr_rt_entries];
395 
396 	new->nr_rt_entries = nr_rt_entries;
397 	for (i = 0; i < 3; i++)
398 		for (j = 0; j < KVM_IOAPIC_NUM_PINS; j++)
399 			new->chip[i][j] = -1;
400 
401 	for (i = 0; i < nr; ++i) {
402 		r = -EINVAL;
403 		if (ue->flags)
404 			goto out;
405 		r = setup_routing_entry(new, &new->rt_entries[i], ue);
406 		if (r)
407 			goto out;
408 		++ue;
409 	}
410 
411 	mutex_lock(&kvm->irq_lock);
412 	old = kvm->irq_routing;
413 	kvm_irq_routing_update(kvm, new);
414 	mutex_unlock(&kvm->irq_lock);
415 
416 	synchronize_rcu();
417 
418 	new = old;
419 	r = 0;
420 
421 out:
422 	kfree(new);
423 	return r;
424 }
425 
426 #define IOAPIC_ROUTING_ENTRY(irq) \
427 	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
428 	  .u.irqchip.irqchip = KVM_IRQCHIP_IOAPIC, .u.irqchip.pin = (irq) }
429 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
430 
431 #ifdef CONFIG_X86
432 #  define PIC_ROUTING_ENTRY(irq) \
433 	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
434 	  .u.irqchip.irqchip = SELECT_PIC(irq), .u.irqchip.pin = (irq) % 8 }
435 #  define ROUTING_ENTRY2(irq) \
436 	IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
437 #else
438 #  define ROUTING_ENTRY2(irq) \
439 	IOAPIC_ROUTING_ENTRY(irq)
440 #endif
441 
442 static const struct kvm_irq_routing_entry default_routing[] = {
443 	ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
444 	ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
445 	ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
446 	ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
447 	ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
448 	ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
449 	ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
450 	ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
451 	ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
452 	ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
453 	ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
454 	ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
455 #ifdef CONFIG_IA64
456 	ROUTING_ENTRY1(24), ROUTING_ENTRY1(25),
457 	ROUTING_ENTRY1(26), ROUTING_ENTRY1(27),
458 	ROUTING_ENTRY1(28), ROUTING_ENTRY1(29),
459 	ROUTING_ENTRY1(30), ROUTING_ENTRY1(31),
460 	ROUTING_ENTRY1(32), ROUTING_ENTRY1(33),
461 	ROUTING_ENTRY1(34), ROUTING_ENTRY1(35),
462 	ROUTING_ENTRY1(36), ROUTING_ENTRY1(37),
463 	ROUTING_ENTRY1(38), ROUTING_ENTRY1(39),
464 	ROUTING_ENTRY1(40), ROUTING_ENTRY1(41),
465 	ROUTING_ENTRY1(42), ROUTING_ENTRY1(43),
466 	ROUTING_ENTRY1(44), ROUTING_ENTRY1(45),
467 	ROUTING_ENTRY1(46), ROUTING_ENTRY1(47),
468 #endif
469 };
470 
kvm_setup_default_irq_routing(struct kvm * kvm)471 int kvm_setup_default_irq_routing(struct kvm *kvm)
472 {
473 	return kvm_set_irq_routing(kvm, default_routing,
474 				   ARRAY_SIZE(default_routing), 0);
475 }
476