xref: /openbmc/linux/arch/x86/kvm/irq_comm.c (revision 9cfc5c90)
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 static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
37 			   struct kvm *kvm, int irq_source_id, int level,
38 			   bool line_status)
39 {
40 	struct kvm_pic *pic = pic_irqchip(kvm);
41 	return kvm_pic_set_irq(pic, e->irqchip.pin, irq_source_id, level);
42 }
43 
44 static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
45 			      struct kvm *kvm, int irq_source_id, int level,
46 			      bool line_status)
47 {
48 	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
49 	return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, irq_source_id, level,
50 				line_status);
51 }
52 
53 int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
54 		struct kvm_lapic_irq *irq, unsigned long *dest_map)
55 {
56 	int i, r = -1;
57 	struct kvm_vcpu *vcpu, *lowest = NULL;
58 
59 	if (irq->dest_mode == 0 && irq->dest_id == 0xff &&
60 			kvm_lowest_prio_delivery(irq)) {
61 		printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
62 		irq->delivery_mode = APIC_DM_FIXED;
63 	}
64 
65 	if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
66 		return r;
67 
68 	kvm_for_each_vcpu(i, vcpu, kvm) {
69 		if (!kvm_apic_present(vcpu))
70 			continue;
71 
72 		if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
73 					irq->dest_id, irq->dest_mode))
74 			continue;
75 
76 		if (!kvm_lowest_prio_delivery(irq)) {
77 			if (r < 0)
78 				r = 0;
79 			r += kvm_apic_set_irq(vcpu, irq, dest_map);
80 		} else if (kvm_lapic_enabled(vcpu)) {
81 			if (!lowest)
82 				lowest = vcpu;
83 			else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
84 				lowest = vcpu;
85 		}
86 	}
87 
88 	if (lowest)
89 		r = kvm_apic_set_irq(lowest, irq, dest_map);
90 
91 	return r;
92 }
93 
94 void kvm_set_msi_irq(struct kvm_kernel_irq_routing_entry *e,
95 		     struct kvm_lapic_irq *irq)
96 {
97 	trace_kvm_msi_set_irq(e->msi.address_lo, e->msi.data);
98 
99 	irq->dest_id = (e->msi.address_lo &
100 			MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
101 	irq->vector = (e->msi.data &
102 			MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
103 	irq->dest_mode = (1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo;
104 	irq->trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
105 	irq->delivery_mode = e->msi.data & 0x700;
106 	irq->msi_redir_hint = ((e->msi.address_lo
107 		& MSI_ADDR_REDIRECTION_LOWPRI) > 0);
108 	irq->level = 1;
109 	irq->shorthand = 0;
110 }
111 EXPORT_SYMBOL_GPL(kvm_set_msi_irq);
112 
113 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
114 		struct kvm *kvm, int irq_source_id, int level, bool line_status)
115 {
116 	struct kvm_lapic_irq irq;
117 
118 	if (!level)
119 		return -1;
120 
121 	kvm_set_msi_irq(e, &irq);
122 
123 	return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
124 }
125 
126 
127 int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
128 			      struct kvm *kvm, int irq_source_id, int level,
129 			      bool line_status)
130 {
131 	struct kvm_lapic_irq irq;
132 	int r;
133 
134 	if (unlikely(e->type != KVM_IRQ_ROUTING_MSI))
135 		return -EWOULDBLOCK;
136 
137 	kvm_set_msi_irq(e, &irq);
138 
139 	if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
140 		return r;
141 	else
142 		return -EWOULDBLOCK;
143 }
144 
145 int kvm_request_irq_source_id(struct kvm *kvm)
146 {
147 	unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
148 	int irq_source_id;
149 
150 	mutex_lock(&kvm->irq_lock);
151 	irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
152 
153 	if (irq_source_id >= BITS_PER_LONG) {
154 		printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
155 		irq_source_id = -EFAULT;
156 		goto unlock;
157 	}
158 
159 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
160 	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
161 	set_bit(irq_source_id, bitmap);
162 unlock:
163 	mutex_unlock(&kvm->irq_lock);
164 
165 	return irq_source_id;
166 }
167 
168 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
169 {
170 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
171 	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
172 
173 	mutex_lock(&kvm->irq_lock);
174 	if (irq_source_id < 0 ||
175 	    irq_source_id >= BITS_PER_LONG) {
176 		printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
177 		goto unlock;
178 	}
179 	clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
180 	if (!ioapic_in_kernel(kvm))
181 		goto unlock;
182 
183 	kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
184 	kvm_pic_clear_all(pic_irqchip(kvm), irq_source_id);
185 unlock:
186 	mutex_unlock(&kvm->irq_lock);
187 }
188 
189 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
190 				    struct kvm_irq_mask_notifier *kimn)
191 {
192 	mutex_lock(&kvm->irq_lock);
193 	kimn->irq = irq;
194 	hlist_add_head_rcu(&kimn->link, &kvm->arch.mask_notifier_list);
195 	mutex_unlock(&kvm->irq_lock);
196 }
197 
198 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
199 				      struct kvm_irq_mask_notifier *kimn)
200 {
201 	mutex_lock(&kvm->irq_lock);
202 	hlist_del_rcu(&kimn->link);
203 	mutex_unlock(&kvm->irq_lock);
204 	synchronize_srcu(&kvm->irq_srcu);
205 }
206 
207 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
208 			     bool mask)
209 {
210 	struct kvm_irq_mask_notifier *kimn;
211 	int idx, gsi;
212 
213 	idx = srcu_read_lock(&kvm->irq_srcu);
214 	gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
215 	if (gsi != -1)
216 		hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
217 			if (kimn->irq == gsi)
218 				kimn->func(kimn, mask);
219 	srcu_read_unlock(&kvm->irq_srcu, idx);
220 }
221 
222 int kvm_set_routing_entry(struct kvm_kernel_irq_routing_entry *e,
223 			  const struct kvm_irq_routing_entry *ue)
224 {
225 	int r = -EINVAL;
226 	int delta;
227 	unsigned max_pin;
228 
229 	switch (ue->type) {
230 	case KVM_IRQ_ROUTING_IRQCHIP:
231 		delta = 0;
232 		switch (ue->u.irqchip.irqchip) {
233 		case KVM_IRQCHIP_PIC_MASTER:
234 			e->set = kvm_set_pic_irq;
235 			max_pin = PIC_NUM_PINS;
236 			break;
237 		case KVM_IRQCHIP_PIC_SLAVE:
238 			e->set = kvm_set_pic_irq;
239 			max_pin = PIC_NUM_PINS;
240 			delta = 8;
241 			break;
242 		case KVM_IRQCHIP_IOAPIC:
243 			max_pin = KVM_IOAPIC_NUM_PINS;
244 			e->set = kvm_set_ioapic_irq;
245 			break;
246 		default:
247 			goto out;
248 		}
249 		e->irqchip.irqchip = ue->u.irqchip.irqchip;
250 		e->irqchip.pin = ue->u.irqchip.pin + delta;
251 		if (e->irqchip.pin >= max_pin)
252 			goto out;
253 		break;
254 	case KVM_IRQ_ROUTING_MSI:
255 		e->set = kvm_set_msi;
256 		e->msi.address_lo = ue->u.msi.address_lo;
257 		e->msi.address_hi = ue->u.msi.address_hi;
258 		e->msi.data = ue->u.msi.data;
259 		break;
260 	default:
261 		goto out;
262 	}
263 
264 	r = 0;
265 out:
266 	return r;
267 }
268 
269 bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
270 			     struct kvm_vcpu **dest_vcpu)
271 {
272 	int i, r = 0;
273 	struct kvm_vcpu *vcpu;
274 
275 	if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
276 		return true;
277 
278 	kvm_for_each_vcpu(i, vcpu, kvm) {
279 		if (!kvm_apic_present(vcpu))
280 			continue;
281 
282 		if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand,
283 					irq->dest_id, irq->dest_mode))
284 			continue;
285 
286 		if (++r == 2)
287 			return false;
288 
289 		*dest_vcpu = vcpu;
290 	}
291 
292 	return r == 1;
293 }
294 EXPORT_SYMBOL_GPL(kvm_intr_is_single_vcpu);
295 
296 #define IOAPIC_ROUTING_ENTRY(irq) \
297 	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
298 	  .u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
299 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
300 
301 #define PIC_ROUTING_ENTRY(irq) \
302 	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
303 	  .u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
304 #define ROUTING_ENTRY2(irq) \
305 	IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
306 
307 static const struct kvm_irq_routing_entry default_routing[] = {
308 	ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
309 	ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
310 	ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
311 	ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
312 	ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
313 	ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
314 	ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
315 	ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
316 	ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
317 	ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
318 	ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
319 	ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
320 };
321 
322 int kvm_setup_default_irq_routing(struct kvm *kvm)
323 {
324 	return kvm_set_irq_routing(kvm, default_routing,
325 				   ARRAY_SIZE(default_routing), 0);
326 }
327 
328 static const struct kvm_irq_routing_entry empty_routing[] = {};
329 
330 int kvm_setup_empty_irq_routing(struct kvm *kvm)
331 {
332 	return kvm_set_irq_routing(kvm, empty_routing, 0, 0);
333 }
334 
335 void kvm_arch_irq_routing_update(struct kvm *kvm)
336 {
337 	if (ioapic_in_kernel(kvm) || !irqchip_in_kernel(kvm))
338 		return;
339 	kvm_make_scan_ioapic_request(kvm);
340 }
341 
342 void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap)
343 {
344 	struct kvm *kvm = vcpu->kvm;
345 	struct kvm_kernel_irq_routing_entry *entry;
346 	struct kvm_irq_routing_table *table;
347 	u32 i, nr_ioapic_pins;
348 	int idx;
349 
350 	/* kvm->irq_routing must be read after clearing
351 	 * KVM_SCAN_IOAPIC. */
352 	smp_mb();
353 	idx = srcu_read_lock(&kvm->irq_srcu);
354 	table = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
355 	nr_ioapic_pins = min_t(u32, table->nr_rt_entries,
356 			       kvm->arch.nr_reserved_ioapic_pins);
357 	for (i = 0; i < nr_ioapic_pins; ++i) {
358 		hlist_for_each_entry(entry, &table->map[i], link) {
359 			u32 dest_id, dest_mode;
360 			bool level;
361 
362 			if (entry->type != KVM_IRQ_ROUTING_MSI)
363 				continue;
364 			dest_id = (entry->msi.address_lo >> 12) & 0xff;
365 			dest_mode = (entry->msi.address_lo >> 2) & 0x1;
366 			level = entry->msi.data & MSI_DATA_TRIGGER_LEVEL;
367 			if (level && kvm_apic_match_dest(vcpu, NULL, 0,
368 						dest_id, dest_mode)) {
369 				u32 vector = entry->msi.data & 0xff;
370 
371 				__set_bit(vector,
372 					  (unsigned long *) eoi_exit_bitmap);
373 			}
374 		}
375 	}
376 	srcu_read_unlock(&kvm->irq_srcu, idx);
377 }
378