vfs: make it possible to access the dentry hash/len as one 64-bit entry
[linux-3.10.git] / virt / kvm / irq_comm.c
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
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
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
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
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
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
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  */
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
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
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
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
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
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
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
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
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
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
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->u.irqchip.irqchip == ei->irqchip.irqchip)
322                         return r;
323
324         e->gsi = ue->gsi;
325         e->type = ue->type;
326         switch (ue->type) {
327         case KVM_IRQ_ROUTING_IRQCHIP:
328                 delta = 0;
329                 switch (ue->u.irqchip.irqchip) {
330                 case KVM_IRQCHIP_PIC_MASTER:
331                         e->set = kvm_set_pic_irq;
332                         max_pin = 16;
333                         break;
334                 case KVM_IRQCHIP_PIC_SLAVE:
335                         e->set = kvm_set_pic_irq;
336                         max_pin = 16;
337                         delta = 8;
338                         break;
339                 case KVM_IRQCHIP_IOAPIC:
340                         max_pin = KVM_IOAPIC_NUM_PINS;
341                         e->set = kvm_set_ioapic_irq;
342                         break;
343                 default:
344                         goto out;
345                 }
346                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
347                 e->irqchip.pin = ue->u.irqchip.pin + delta;
348                 if (e->irqchip.pin >= max_pin)
349                         goto out;
350                 rt->chip[ue->u.irqchip.irqchip][e->irqchip.pin] = ue->gsi;
351                 break;
352         case KVM_IRQ_ROUTING_MSI:
353                 e->set = kvm_set_msi;
354                 e->msi.address_lo = ue->u.msi.address_lo;
355                 e->msi.address_hi = ue->u.msi.address_hi;
356                 e->msi.data = ue->u.msi.data;
357                 break;
358         default:
359                 goto out;
360         }
361
362         hlist_add_head(&e->link, &rt->map[e->gsi]);
363         r = 0;
364 out:
365         return r;
366 }
367
368
369 int kvm_set_irq_routing(struct kvm *kvm,
370                         const struct kvm_irq_routing_entry *ue,
371                         unsigned nr,
372                         unsigned flags)
373 {
374         struct kvm_irq_routing_table *new, *old;
375         u32 i, j, nr_rt_entries = 0;
376         int r;
377
378         for (i = 0; i < nr; ++i) {
379                 if (ue[i].gsi >= KVM_MAX_IRQ_ROUTES)
380                         return -EINVAL;
381                 nr_rt_entries = max(nr_rt_entries, ue[i].gsi);
382         }
383
384         nr_rt_entries += 1;
385
386         new = kzalloc(sizeof(*new) + (nr_rt_entries * sizeof(struct hlist_head))
387                       + (nr * sizeof(struct kvm_kernel_irq_routing_entry)),
388                       GFP_KERNEL);
389
390         if (!new)
391                 return -ENOMEM;
392
393         new->rt_entries = (void *)&new->map[nr_rt_entries];
394
395         new->nr_rt_entries = nr_rt_entries;
396         for (i = 0; i < 3; i++)
397                 for (j = 0; j < KVM_IOAPIC_NUM_PINS; j++)
398                         new->chip[i][j] = -1;
399
400         for (i = 0; i < nr; ++i) {
401                 r = -EINVAL;
402                 if (ue->flags)
403                         goto out;
404                 r = setup_routing_entry(new, &new->rt_entries[i], ue);
405                 if (r)
406                         goto out;
407                 ++ue;
408         }
409
410         mutex_lock(&kvm->irq_lock);
411         old = kvm->irq_routing;
412         kvm_irq_routing_update(kvm, new);
413         mutex_unlock(&kvm->irq_lock);
414
415         synchronize_rcu();
416
417         new = old;
418         r = 0;
419
420 out:
421         kfree(new);
422         return r;
423 }
424
425 #define IOAPIC_ROUTING_ENTRY(irq) \
426         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
427           .u.irqchip.irqchip = KVM_IRQCHIP_IOAPIC, .u.irqchip.pin = (irq) }
428 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
429
430 #ifdef CONFIG_X86
431 #  define PIC_ROUTING_ENTRY(irq) \
432         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
433           .u.irqchip.irqchip = SELECT_PIC(irq), .u.irqchip.pin = (irq) % 8 }
434 #  define ROUTING_ENTRY2(irq) \
435         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
436 #else
437 #  define ROUTING_ENTRY2(irq) \
438         IOAPIC_ROUTING_ENTRY(irq)
439 #endif
440
441 static const struct kvm_irq_routing_entry default_routing[] = {
442         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
443         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
444         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
445         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
446         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
447         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
448         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
449         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
450         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
451         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
452         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
453         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
454 #ifdef CONFIG_IA64
455         ROUTING_ENTRY1(24), ROUTING_ENTRY1(25),
456         ROUTING_ENTRY1(26), ROUTING_ENTRY1(27),
457         ROUTING_ENTRY1(28), ROUTING_ENTRY1(29),
458         ROUTING_ENTRY1(30), ROUTING_ENTRY1(31),
459         ROUTING_ENTRY1(32), ROUTING_ENTRY1(33),
460         ROUTING_ENTRY1(34), ROUTING_ENTRY1(35),
461         ROUTING_ENTRY1(36), ROUTING_ENTRY1(37),
462         ROUTING_ENTRY1(38), ROUTING_ENTRY1(39),
463         ROUTING_ENTRY1(40), ROUTING_ENTRY1(41),
464         ROUTING_ENTRY1(42), ROUTING_ENTRY1(43),
465         ROUTING_ENTRY1(44), ROUTING_ENTRY1(45),
466         ROUTING_ENTRY1(46), ROUTING_ENTRY1(47),
467 #endif
468 };
469
470 int kvm_setup_default_irq_routing(struct kvm *kvm)
471 {
472         return kvm_set_irq_routing(kvm, default_routing,
473                                    ARRAY_SIZE(default_routing), 0);
474 }