xref: /openbmc/linux/arch/x86/kvm/irq_comm.c (revision 781095f903f398148cd0b646d3984234a715f29e)
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 
38 static int kvm_set_pic_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_pic *pic = pic_irqchip(kvm);
43 	return kvm_pic_set_irq(pic, e->irqchip.pin, irq_source_id, level);
44 }
45 
46 static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
47 			      struct kvm *kvm, int irq_source_id, int level,
48 			      bool line_status)
49 {
50 	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
51 	return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, irq_source_id, level,
52 				line_status);
53 }
54 
55 int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
56 		struct kvm_lapic_irq *irq, unsigned long *dest_map)
57 {
58 	int i, r = -1;
59 	struct kvm_vcpu *vcpu, *lowest = NULL;
60 
61 	if (irq->dest_mode == 0 && irq->dest_id == 0xff &&
62 			kvm_lowest_prio_delivery(irq)) {
63 		printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
64 		irq->delivery_mode = APIC_DM_FIXED;
65 	}
66 
67 	if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
68 		return r;
69 
70 	kvm_for_each_vcpu(i, vcpu, kvm) {
71 		if (!kvm_apic_present(vcpu))
72 			continue;
73 
74 		if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
75 					irq->dest_id, irq->dest_mode))
76 			continue;
77 
78 		if (!kvm_lowest_prio_delivery(irq)) {
79 			if (r < 0)
80 				r = 0;
81 			r += kvm_apic_set_irq(vcpu, irq, dest_map);
82 		} else if (kvm_lapic_enabled(vcpu)) {
83 			if (!lowest)
84 				lowest = vcpu;
85 			else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
86 				lowest = vcpu;
87 		}
88 	}
89 
90 	if (lowest)
91 		r = kvm_apic_set_irq(lowest, irq, dest_map);
92 
93 	return r;
94 }
95 
96 void kvm_set_msi_irq(struct kvm_kernel_irq_routing_entry *e,
97 		     struct kvm_lapic_irq *irq)
98 {
99 	trace_kvm_msi_set_irq(e->msi.address_lo, e->msi.data);
100 
101 	irq->dest_id = (e->msi.address_lo &
102 			MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
103 	irq->vector = (e->msi.data &
104 			MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
105 	irq->dest_mode = (1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo;
106 	irq->trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
107 	irq->delivery_mode = e->msi.data & 0x700;
108 	irq->msi_redir_hint = ((e->msi.address_lo
109 		& MSI_ADDR_REDIRECTION_LOWPRI) > 0);
110 	irq->level = 1;
111 	irq->shorthand = 0;
112 }
113 EXPORT_SYMBOL_GPL(kvm_set_msi_irq);
114 
115 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
116 		struct kvm *kvm, int irq_source_id, int level, bool line_status)
117 {
118 	struct kvm_lapic_irq irq;
119 
120 	if (!level)
121 		return -1;
122 
123 	kvm_set_msi_irq(e, &irq);
124 
125 	return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
126 }
127 
128 
129 int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
130 			      struct kvm *kvm, int irq_source_id, int level,
131 			      bool line_status)
132 {
133 	struct kvm_lapic_irq irq;
134 	int r;
135 
136 	if (unlikely(e->type != KVM_IRQ_ROUTING_MSI))
137 		return -EWOULDBLOCK;
138 
139 	kvm_set_msi_irq(e, &irq);
140 
141 	if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
142 		return r;
143 	else
144 		return -EWOULDBLOCK;
145 }
146 
147 int kvm_request_irq_source_id(struct kvm *kvm)
148 {
149 	unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
150 	int irq_source_id;
151 
152 	mutex_lock(&kvm->irq_lock);
153 	irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
154 
155 	if (irq_source_id >= BITS_PER_LONG) {
156 		printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
157 		irq_source_id = -EFAULT;
158 		goto unlock;
159 	}
160 
161 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
162 	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
163 	set_bit(irq_source_id, bitmap);
164 unlock:
165 	mutex_unlock(&kvm->irq_lock);
166 
167 	return irq_source_id;
168 }
169 
170 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
171 {
172 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
173 	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
174 
175 	mutex_lock(&kvm->irq_lock);
176 	if (irq_source_id < 0 ||
177 	    irq_source_id >= BITS_PER_LONG) {
178 		printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
179 		goto unlock;
180 	}
181 	clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
182 	if (!ioapic_in_kernel(kvm))
183 		goto unlock;
184 
185 	kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
186 	kvm_pic_clear_all(pic_irqchip(kvm), irq_source_id);
187 unlock:
188 	mutex_unlock(&kvm->irq_lock);
189 }
190 
191 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
192 				    struct kvm_irq_mask_notifier *kimn)
193 {
194 	mutex_lock(&kvm->irq_lock);
195 	kimn->irq = irq;
196 	hlist_add_head_rcu(&kimn->link, &kvm->arch.mask_notifier_list);
197 	mutex_unlock(&kvm->irq_lock);
198 }
199 
200 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
201 				      struct kvm_irq_mask_notifier *kimn)
202 {
203 	mutex_lock(&kvm->irq_lock);
204 	hlist_del_rcu(&kimn->link);
205 	mutex_unlock(&kvm->irq_lock);
206 	synchronize_srcu(&kvm->irq_srcu);
207 }
208 
209 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
210 			     bool mask)
211 {
212 	struct kvm_irq_mask_notifier *kimn;
213 	int idx, gsi;
214 
215 	idx = srcu_read_lock(&kvm->irq_srcu);
216 	gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
217 	if (gsi != -1)
218 		hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
219 			if (kimn->irq == gsi)
220 				kimn->func(kimn, mask);
221 	srcu_read_unlock(&kvm->irq_srcu, idx);
222 }
223 
224 static int kvm_hv_set_sint(struct kvm_kernel_irq_routing_entry *e,
225 		    struct kvm *kvm, int irq_source_id, int level,
226 		    bool line_status)
227 {
228 	if (!level)
229 		return -1;
230 
231 	return kvm_hv_synic_set_irq(kvm, e->hv_sint.vcpu, e->hv_sint.sint);
232 }
233 
234 int kvm_set_routing_entry(struct kvm_kernel_irq_routing_entry *e,
235 			  const struct kvm_irq_routing_entry *ue)
236 {
237 	int r = -EINVAL;
238 	int delta;
239 	unsigned max_pin;
240 
241 	switch (ue->type) {
242 	case KVM_IRQ_ROUTING_IRQCHIP:
243 		delta = 0;
244 		switch (ue->u.irqchip.irqchip) {
245 		case KVM_IRQCHIP_PIC_MASTER:
246 			e->set = kvm_set_pic_irq;
247 			max_pin = PIC_NUM_PINS;
248 			break;
249 		case KVM_IRQCHIP_PIC_SLAVE:
250 			e->set = kvm_set_pic_irq;
251 			max_pin = PIC_NUM_PINS;
252 			delta = 8;
253 			break;
254 		case KVM_IRQCHIP_IOAPIC:
255 			max_pin = KVM_IOAPIC_NUM_PINS;
256 			e->set = kvm_set_ioapic_irq;
257 			break;
258 		default:
259 			goto out;
260 		}
261 		e->irqchip.irqchip = ue->u.irqchip.irqchip;
262 		e->irqchip.pin = ue->u.irqchip.pin + delta;
263 		if (e->irqchip.pin >= max_pin)
264 			goto out;
265 		break;
266 	case KVM_IRQ_ROUTING_MSI:
267 		e->set = kvm_set_msi;
268 		e->msi.address_lo = ue->u.msi.address_lo;
269 		e->msi.address_hi = ue->u.msi.address_hi;
270 		e->msi.data = ue->u.msi.data;
271 		break;
272 	case KVM_IRQ_ROUTING_HV_SINT:
273 		e->set = kvm_hv_set_sint;
274 		e->hv_sint.vcpu = ue->u.hv_sint.vcpu;
275 		e->hv_sint.sint = ue->u.hv_sint.sint;
276 		break;
277 	default:
278 		goto out;
279 	}
280 
281 	r = 0;
282 out:
283 	return r;
284 }
285 
286 bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
287 			     struct kvm_vcpu **dest_vcpu)
288 {
289 	int i, r = 0;
290 	struct kvm_vcpu *vcpu;
291 
292 	if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
293 		return true;
294 
295 	kvm_for_each_vcpu(i, vcpu, kvm) {
296 		if (!kvm_apic_present(vcpu))
297 			continue;
298 
299 		if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand,
300 					irq->dest_id, irq->dest_mode))
301 			continue;
302 
303 		if (++r == 2)
304 			return false;
305 
306 		*dest_vcpu = vcpu;
307 	}
308 
309 	return r == 1;
310 }
311 EXPORT_SYMBOL_GPL(kvm_intr_is_single_vcpu);
312 
313 #define IOAPIC_ROUTING_ENTRY(irq) \
314 	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
315 	  .u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
316 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
317 
318 #define PIC_ROUTING_ENTRY(irq) \
319 	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
320 	  .u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
321 #define ROUTING_ENTRY2(irq) \
322 	IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
323 
324 static const struct kvm_irq_routing_entry default_routing[] = {
325 	ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
326 	ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
327 	ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
328 	ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
329 	ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
330 	ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
331 	ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
332 	ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
333 	ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
334 	ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
335 	ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
336 	ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
337 };
338 
339 int kvm_setup_default_irq_routing(struct kvm *kvm)
340 {
341 	return kvm_set_irq_routing(kvm, default_routing,
342 				   ARRAY_SIZE(default_routing), 0);
343 }
344 
345 static const struct kvm_irq_routing_entry empty_routing[] = {};
346 
347 int kvm_setup_empty_irq_routing(struct kvm *kvm)
348 {
349 	return kvm_set_irq_routing(kvm, empty_routing, 0, 0);
350 }
351 
352 void kvm_arch_post_irq_routing_update(struct kvm *kvm)
353 {
354 	if (ioapic_in_kernel(kvm) || !irqchip_in_kernel(kvm))
355 		return;
356 	kvm_make_scan_ioapic_request(kvm);
357 }
358 
359 void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu,
360 			    ulong *ioapic_handled_vectors)
361 {
362 	struct kvm *kvm = vcpu->kvm;
363 	struct kvm_kernel_irq_routing_entry *entry;
364 	struct kvm_irq_routing_table *table;
365 	u32 i, nr_ioapic_pins;
366 	int idx;
367 
368 	/* kvm->irq_routing must be read after clearing
369 	 * KVM_SCAN_IOAPIC. */
370 	smp_mb();
371 	idx = srcu_read_lock(&kvm->irq_srcu);
372 	table = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
373 	nr_ioapic_pins = min_t(u32, table->nr_rt_entries,
374 			       kvm->arch.nr_reserved_ioapic_pins);
375 	for (i = 0; i < nr_ioapic_pins; ++i) {
376 		hlist_for_each_entry(entry, &table->map[i], link) {
377 			u32 dest_id, dest_mode;
378 			bool level;
379 
380 			if (entry->type != KVM_IRQ_ROUTING_MSI)
381 				continue;
382 			dest_id = (entry->msi.address_lo >> 12) & 0xff;
383 			dest_mode = (entry->msi.address_lo >> 2) & 0x1;
384 			level = entry->msi.data & MSI_DATA_TRIGGER_LEVEL;
385 			if (level && kvm_apic_match_dest(vcpu, NULL, 0,
386 						dest_id, dest_mode)) {
387 				u32 vector = entry->msi.data & 0xff;
388 
389 				__set_bit(vector,
390 					  ioapic_handled_vectors);
391 			}
392 		}
393 	}
394 	srcu_read_unlock(&kvm->irq_srcu, idx);
395 }
396 
397 int kvm_arch_set_irq(struct kvm_kernel_irq_routing_entry *irq, struct kvm *kvm,
398 		     int irq_source_id, int level, bool line_status)
399 {
400 	switch (irq->type) {
401 	case KVM_IRQ_ROUTING_HV_SINT:
402 		return kvm_hv_set_sint(irq, kvm, irq_source_id, level,
403 				       line_status);
404 	default:
405 		return -EWOULDBLOCK;
406 	}
407 }
408 
409 void kvm_arch_irq_routing_update(struct kvm *kvm)
410 {
411 	kvm_hv_irq_routing_update(kvm);
412 }
413