xref: /openbmc/linux/arch/x86/kvm/irq_comm.c (revision 78700c0a)
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 <linux/export.h>
26 #include <trace/events/kvm.h>
27 
28 #include <asm/msidef.h>
29 
30 #include "irq.h"
31 
32 #include "ioapic.h"
33 
34 #include "lapic.h"
35 
36 #include "hyperv.h"
37 #include "x86.h"
38 
39 static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
40 			   struct kvm *kvm, int irq_source_id, int level,
41 			   bool line_status)
42 {
43 	struct kvm_pic *pic = pic_irqchip(kvm);
44 	return kvm_pic_set_irq(pic, e->irqchip.pin, irq_source_id, level);
45 }
46 
47 static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
48 			      struct kvm *kvm, int irq_source_id, int level,
49 			      bool line_status)
50 {
51 	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
52 	return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, irq_source_id, level,
53 				line_status);
54 }
55 
56 int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
57 		struct kvm_lapic_irq *irq, struct dest_map *dest_map)
58 {
59 	int i, r = -1;
60 	struct kvm_vcpu *vcpu, *lowest = NULL;
61 	unsigned long dest_vcpu_bitmap[BITS_TO_LONGS(KVM_MAX_VCPUS)];
62 	unsigned int dest_vcpus = 0;
63 
64 	if (irq->dest_mode == 0 && irq->dest_id == 0xff &&
65 			kvm_lowest_prio_delivery(irq)) {
66 		printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
67 		irq->delivery_mode = APIC_DM_FIXED;
68 	}
69 
70 	if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
71 		return r;
72 
73 	memset(dest_vcpu_bitmap, 0, sizeof(dest_vcpu_bitmap));
74 
75 	kvm_for_each_vcpu(i, vcpu, kvm) {
76 		if (!kvm_apic_present(vcpu))
77 			continue;
78 
79 		if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
80 					irq->dest_id, irq->dest_mode))
81 			continue;
82 
83 		if (!kvm_lowest_prio_delivery(irq)) {
84 			if (r < 0)
85 				r = 0;
86 			r += kvm_apic_set_irq(vcpu, irq, dest_map);
87 		} else if (kvm_lapic_enabled(vcpu)) {
88 			if (!kvm_vector_hashing_enabled()) {
89 				if (!lowest)
90 					lowest = vcpu;
91 				else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
92 					lowest = vcpu;
93 			} else {
94 				__set_bit(i, dest_vcpu_bitmap);
95 				dest_vcpus++;
96 			}
97 		}
98 	}
99 
100 	if (dest_vcpus != 0) {
101 		int idx = kvm_vector_to_index(irq->vector, dest_vcpus,
102 					dest_vcpu_bitmap, KVM_MAX_VCPUS);
103 
104 		lowest = kvm_get_vcpu(kvm, idx);
105 	}
106 
107 	if (lowest)
108 		r = kvm_apic_set_irq(lowest, irq, dest_map);
109 
110 	return r;
111 }
112 
113 void kvm_set_msi_irq(struct kvm_kernel_irq_routing_entry *e,
114 		     struct kvm_lapic_irq *irq)
115 {
116 	trace_kvm_msi_set_irq(e->msi.address_lo, e->msi.data);
117 
118 	irq->dest_id = (e->msi.address_lo &
119 			MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
120 	irq->vector = (e->msi.data &
121 			MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
122 	irq->dest_mode = (1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo;
123 	irq->trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
124 	irq->delivery_mode = e->msi.data & 0x700;
125 	irq->msi_redir_hint = ((e->msi.address_lo
126 		& MSI_ADDR_REDIRECTION_LOWPRI) > 0);
127 	irq->level = 1;
128 	irq->shorthand = 0;
129 }
130 EXPORT_SYMBOL_GPL(kvm_set_msi_irq);
131 
132 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
133 		struct kvm *kvm, int irq_source_id, int level, bool line_status)
134 {
135 	struct kvm_lapic_irq irq;
136 
137 	if (!level)
138 		return -1;
139 
140 	kvm_set_msi_irq(e, &irq);
141 
142 	return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
143 }
144 
145 
146 int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
147 			      struct kvm *kvm, int irq_source_id, int level,
148 			      bool line_status)
149 {
150 	struct kvm_lapic_irq irq;
151 	int r;
152 
153 	if (unlikely(e->type != KVM_IRQ_ROUTING_MSI))
154 		return -EWOULDBLOCK;
155 
156 	kvm_set_msi_irq(e, &irq);
157 
158 	if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
159 		return r;
160 	else
161 		return -EWOULDBLOCK;
162 }
163 
164 int kvm_request_irq_source_id(struct kvm *kvm)
165 {
166 	unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
167 	int irq_source_id;
168 
169 	mutex_lock(&kvm->irq_lock);
170 	irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
171 
172 	if (irq_source_id >= BITS_PER_LONG) {
173 		printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
174 		irq_source_id = -EFAULT;
175 		goto unlock;
176 	}
177 
178 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
179 	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
180 	set_bit(irq_source_id, bitmap);
181 unlock:
182 	mutex_unlock(&kvm->irq_lock);
183 
184 	return irq_source_id;
185 }
186 
187 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
188 {
189 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
190 	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
191 
192 	mutex_lock(&kvm->irq_lock);
193 	if (irq_source_id < 0 ||
194 	    irq_source_id >= BITS_PER_LONG) {
195 		printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
196 		goto unlock;
197 	}
198 	clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
199 	if (!ioapic_in_kernel(kvm))
200 		goto unlock;
201 
202 	kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
203 	kvm_pic_clear_all(pic_irqchip(kvm), irq_source_id);
204 unlock:
205 	mutex_unlock(&kvm->irq_lock);
206 }
207 
208 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
209 				    struct kvm_irq_mask_notifier *kimn)
210 {
211 	mutex_lock(&kvm->irq_lock);
212 	kimn->irq = irq;
213 	hlist_add_head_rcu(&kimn->link, &kvm->arch.mask_notifier_list);
214 	mutex_unlock(&kvm->irq_lock);
215 }
216 
217 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
218 				      struct kvm_irq_mask_notifier *kimn)
219 {
220 	mutex_lock(&kvm->irq_lock);
221 	hlist_del_rcu(&kimn->link);
222 	mutex_unlock(&kvm->irq_lock);
223 	synchronize_srcu(&kvm->irq_srcu);
224 }
225 
226 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
227 			     bool mask)
228 {
229 	struct kvm_irq_mask_notifier *kimn;
230 	int idx, gsi;
231 
232 	idx = srcu_read_lock(&kvm->irq_srcu);
233 	gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
234 	if (gsi != -1)
235 		hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
236 			if (kimn->irq == gsi)
237 				kimn->func(kimn, mask);
238 	srcu_read_unlock(&kvm->irq_srcu, idx);
239 }
240 
241 static int kvm_hv_set_sint(struct kvm_kernel_irq_routing_entry *e,
242 		    struct kvm *kvm, int irq_source_id, int level,
243 		    bool line_status)
244 {
245 	if (!level)
246 		return -1;
247 
248 	return kvm_hv_synic_set_irq(kvm, e->hv_sint.vcpu, e->hv_sint.sint);
249 }
250 
251 int kvm_set_routing_entry(struct kvm_kernel_irq_routing_entry *e,
252 			  const struct kvm_irq_routing_entry *ue)
253 {
254 	int r = -EINVAL;
255 	int delta;
256 	unsigned max_pin;
257 
258 	switch (ue->type) {
259 	case KVM_IRQ_ROUTING_IRQCHIP:
260 		delta = 0;
261 		switch (ue->u.irqchip.irqchip) {
262 		case KVM_IRQCHIP_PIC_MASTER:
263 			e->set = kvm_set_pic_irq;
264 			max_pin = PIC_NUM_PINS;
265 			break;
266 		case KVM_IRQCHIP_PIC_SLAVE:
267 			e->set = kvm_set_pic_irq;
268 			max_pin = PIC_NUM_PINS;
269 			delta = 8;
270 			break;
271 		case KVM_IRQCHIP_IOAPIC:
272 			max_pin = KVM_IOAPIC_NUM_PINS;
273 			e->set = kvm_set_ioapic_irq;
274 			break;
275 		default:
276 			goto out;
277 		}
278 		e->irqchip.irqchip = ue->u.irqchip.irqchip;
279 		e->irqchip.pin = ue->u.irqchip.pin + delta;
280 		if (e->irqchip.pin >= max_pin)
281 			goto out;
282 		break;
283 	case KVM_IRQ_ROUTING_MSI:
284 		e->set = kvm_set_msi;
285 		e->msi.address_lo = ue->u.msi.address_lo;
286 		e->msi.address_hi = ue->u.msi.address_hi;
287 		e->msi.data = ue->u.msi.data;
288 		break;
289 	case KVM_IRQ_ROUTING_HV_SINT:
290 		e->set = kvm_hv_set_sint;
291 		e->hv_sint.vcpu = ue->u.hv_sint.vcpu;
292 		e->hv_sint.sint = ue->u.hv_sint.sint;
293 		break;
294 	default:
295 		goto out;
296 	}
297 
298 	r = 0;
299 out:
300 	return r;
301 }
302 
303 bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
304 			     struct kvm_vcpu **dest_vcpu)
305 {
306 	int i, r = 0;
307 	struct kvm_vcpu *vcpu;
308 
309 	if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
310 		return true;
311 
312 	kvm_for_each_vcpu(i, vcpu, kvm) {
313 		if (!kvm_apic_present(vcpu))
314 			continue;
315 
316 		if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand,
317 					irq->dest_id, irq->dest_mode))
318 			continue;
319 
320 		if (++r == 2)
321 			return false;
322 
323 		*dest_vcpu = vcpu;
324 	}
325 
326 	return r == 1;
327 }
328 EXPORT_SYMBOL_GPL(kvm_intr_is_single_vcpu);
329 
330 #define IOAPIC_ROUTING_ENTRY(irq) \
331 	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
332 	  .u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
333 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
334 
335 #define PIC_ROUTING_ENTRY(irq) \
336 	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
337 	  .u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
338 #define ROUTING_ENTRY2(irq) \
339 	IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
340 
341 static const struct kvm_irq_routing_entry default_routing[] = {
342 	ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
343 	ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
344 	ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
345 	ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
346 	ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
347 	ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
348 	ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
349 	ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
350 	ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
351 	ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
352 	ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
353 	ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
354 };
355 
356 int kvm_setup_default_irq_routing(struct kvm *kvm)
357 {
358 	return kvm_set_irq_routing(kvm, default_routing,
359 				   ARRAY_SIZE(default_routing), 0);
360 }
361 
362 static const struct kvm_irq_routing_entry empty_routing[] = {};
363 
364 int kvm_setup_empty_irq_routing(struct kvm *kvm)
365 {
366 	return kvm_set_irq_routing(kvm, empty_routing, 0, 0);
367 }
368 
369 void kvm_arch_post_irq_routing_update(struct kvm *kvm)
370 {
371 	if (ioapic_in_kernel(kvm) || !irqchip_in_kernel(kvm))
372 		return;
373 	kvm_make_scan_ioapic_request(kvm);
374 }
375 
376 void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu,
377 			    ulong *ioapic_handled_vectors)
378 {
379 	struct kvm *kvm = vcpu->kvm;
380 	struct kvm_kernel_irq_routing_entry *entry;
381 	struct kvm_irq_routing_table *table;
382 	u32 i, nr_ioapic_pins;
383 	int idx;
384 
385 	idx = srcu_read_lock(&kvm->irq_srcu);
386 	table = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
387 	nr_ioapic_pins = min_t(u32, table->nr_rt_entries,
388 			       kvm->arch.nr_reserved_ioapic_pins);
389 	for (i = 0; i < nr_ioapic_pins; ++i) {
390 		hlist_for_each_entry(entry, &table->map[i], link) {
391 			u32 dest_id, dest_mode;
392 			bool level;
393 
394 			if (entry->type != KVM_IRQ_ROUTING_MSI)
395 				continue;
396 			dest_id = (entry->msi.address_lo >> 12) & 0xff;
397 			dest_mode = (entry->msi.address_lo >> 2) & 0x1;
398 			level = entry->msi.data & MSI_DATA_TRIGGER_LEVEL;
399 			if (level && kvm_apic_match_dest(vcpu, NULL, 0,
400 						dest_id, dest_mode)) {
401 				u32 vector = entry->msi.data & 0xff;
402 
403 				__set_bit(vector,
404 					  ioapic_handled_vectors);
405 			}
406 		}
407 	}
408 	srcu_read_unlock(&kvm->irq_srcu, idx);
409 }
410 
411 int kvm_arch_set_irq(struct kvm_kernel_irq_routing_entry *irq, struct kvm *kvm,
412 		     int irq_source_id, int level, bool line_status)
413 {
414 	switch (irq->type) {
415 	case KVM_IRQ_ROUTING_HV_SINT:
416 		return kvm_hv_set_sint(irq, kvm, irq_source_id, level,
417 				       line_status);
418 	default:
419 		return -EWOULDBLOCK;
420 	}
421 }
422 
423 void kvm_arch_irq_routing_update(struct kvm *kvm)
424 {
425 	kvm_hv_irq_routing_update(kvm);
426 }
427