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