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 <linux/export.h>
  26 #include <trace/events/kvm.h>
  27
  28 #include <asm/msidef.h>
  29 #ifdef CONFIG_IA64
  30 #include <asm/iosapic.h>
  31 #endif
  32
  33 #include "irq.h"
  34
  35 #include "ioapic.h"
  36
  37 static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
  38                            struct kvm *kvm, int irq_source_id, int level)
  39 {
  40 #ifdef CONFIG_X86
  41         struct kvm_pic *pic = pic_irqchip(kvm);
  42         return kvm_pic_set_irq(pic, e->irqchip.pin, irq_source_id, level);
  43 #else
  44         return -1;
  45 #endif
  46 }
  47
  48 static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
  49                               struct kvm *kvm, int irq_source_id, int level)
  50 {
  51         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
  52         return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, irq_source_id, level);
  53 }
  54
  55 inline static bool kvm_is_dm_lowest_prio(struct kvm_lapic_irq *irq)
  56 {
  57 #ifdef CONFIG_IA64
  58         return irq->delivery_mode ==
  59                 (IOSAPIC_LOWEST_PRIORITY << IOSAPIC_DELIVERY_SHIFT);
  60 #else
  61         return irq->delivery_mode == APIC_DM_LOWEST;
  62 #endif
  63 }
  64
  65 int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
  66                 struct kvm_lapic_irq *irq)
  67 {
  68         int i, r = -1;
  69         struct kvm_vcpu *vcpu, *lowest = NULL;
  70
  71         if (irq->dest_mode == 0 && irq->dest_id == 0xff &&
  72                         kvm_is_dm_lowest_prio(irq)) {
  73                 printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
  74                 irq->delivery_mode = APIC_DM_FIXED;
  75         }
  76
  77         if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r))
  78                 return r;
  79
  80         kvm_for_each_vcpu(i, vcpu, kvm) {
  81                 if (!kvm_apic_present(vcpu))
  82                         continue;
  83
  84                 if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
  85                                         irq->dest_id, irq->dest_mode))
  86                         continue;
  87
  88                 if (!kvm_is_dm_lowest_prio(irq)) {
  89                         if (r < 0)
  90                                 r = 0;
  91                         r += kvm_apic_set_irq(vcpu, irq);
  92                 } else if (kvm_lapic_enabled(vcpu)) {
  93                         if (!lowest)
  94                                 lowest = vcpu;
  95                         else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
  96                                 lowest = vcpu;
  97                 }
  98         }
  99
 100         if (lowest)
 101                 r = kvm_apic_set_irq(lowest, irq);
 102
 103         return r;
 104 }
 105
 106 static inline void kvm_set_msi_irq(struct kvm_kernel_irq_routing_entry *e,
 107                                    struct kvm_lapic_irq *irq)
 108 {
 109         trace_kvm_msi_set_irq(e->msi.address_lo, e->msi.data);
 110
 111         irq->dest_id = (e->msi.address_lo &
 112                         MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
 113         irq->vector = (e->msi.data &
 114                         MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
 115         irq->dest_mode = (1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo;
 116         irq->trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
 117         irq->delivery_mode = e->msi.data & 0x700;
 118         irq->level = 1;
 119         irq->shorthand = 0;
 120         /* TODO Deal with RH bit of MSI message address */
 121 }
 122
 123 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
 124                 struct kvm *kvm, int irq_source_id, int level)
 125 {
 126         struct kvm_lapic_irq irq;
 127
 128         if (!level)
 129                 return -1;
 130
 131         kvm_set_msi_irq(e, &irq);
 132
 133         return kvm_irq_delivery_to_apic(kvm, NULL, &irq);
 134 }
 135
 136
 137 static int kvm_set_msi_inatomic(struct kvm_kernel_irq_routing_entry *e,
 138                          struct kvm *kvm)
 139 {
 140         struct kvm_lapic_irq irq;
 141         int r;
 142
 143         kvm_set_msi_irq(e, &irq);
 144
 145         if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r))
 146                 return r;
 147         else
 148                 return -EWOULDBLOCK;
 149 }
 150
 151 int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi)
 152 {
 153         struct kvm_kernel_irq_routing_entry route;
 154
 155         if (!irqchip_in_kernel(kvm) || msi->flags != 0)
 156                 return -EINVAL;
 157
 158         route.msi.address_lo = msi->address_lo;
 159         route.msi.address_hi = msi->address_hi;
 160         route.msi.data = msi->data;
 161
 162         return kvm_set_msi(&route, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, 1);
 163 }
 164
 165 /*
 166  * Return value:
 167  *  < 0   Interrupt was ignored (masked or not delivered for other reasons)
 168  *  = 0   Interrupt was coalesced (previous irq is still pending)
 169  *  > 0   Number of CPUs interrupt was delivered to
 170  */
 171 int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level)
 172 {
 173         struct kvm_kernel_irq_routing_entry *e, irq_set[KVM_NR_IRQCHIPS];
 174         int ret = -1, i = 0;
 175         struct kvm_irq_routing_table *irq_rt;
 176         struct hlist_node *n;
 177
 178         trace_kvm_set_irq(irq, level, irq_source_id);
 179
 180         /* Not possible to detect if the guest uses the PIC or the
 181          * IOAPIC.  So set the bit in both. The guest will ignore
 182          * writes to the unused one.
 183          */
 184         rcu_read_lock();
 185         irq_rt = rcu_dereference(kvm->irq_routing);
 186         if (irq < irq_rt->nr_rt_entries)
 187                 hlist_for_each_entry(e, n, &irq_rt->map[irq], link)
 188                         irq_set[i++] = *e;
 189         rcu_read_unlock();
 190
 191         while(i--) {
 192                 int r;
 193                 r = irq_set[i].set(&irq_set[i], kvm, irq_source_id, level);
 194                 if (r < 0)
 195                         continue;
 196
 197                 ret = r + ((ret < 0) ? 0 : ret);
 198         }
 199
 200         return ret;
 201 }
 202
 203 /*
 204  * Deliver an IRQ in an atomic context if we can, or return a failure,
 205  * user can retry in a process context.
 206  * Return value:
 207  *  -EWOULDBLOCK - Can't deliver in atomic context: retry in a process context.
 208  *  Other values - No need to retry.
 209  */
 210 int kvm_set_irq_inatomic(struct kvm *kvm, int irq_source_id, u32 irq, int level)
 211 {
 212         struct kvm_kernel_irq_routing_entry *e;
 213         int ret = -EINVAL;
 214         struct kvm_irq_routing_table *irq_rt;
 215         struct hlist_node *n;
 216
 217         trace_kvm_set_irq(irq, level, irq_source_id);
 218
 219         /*
 220          * Injection into either PIC or IOAPIC might need to scan all CPUs,
 221          * which would need to be retried from thread context;  when same GSI
 222          * is connected to both PIC and IOAPIC, we'd have to report a
 223          * partial failure here.
 224          * Since there's no easy way to do this, we only support injecting MSI
 225          * which is limited to 1:1 GSI mapping.
 226          */
 227         rcu_read_lock();
 228         irq_rt = rcu_dereference(kvm->irq_routing);
 229         if (irq < irq_rt->nr_rt_entries)
 230                 hlist_for_each_entry(e, n, &irq_rt->map[irq], link) {
 231                         if (likely(e->type == KVM_IRQ_ROUTING_MSI))
 232                                 ret = kvm_set_msi_inatomic(e, kvm);
 233                         else
 234                                 ret = -EWOULDBLOCK;
 235                         break;
 236                 }
 237         rcu_read_unlock();
 238         return ret;
 239 }
 240
 241 bool kvm_irq_has_notifier(struct kvm *kvm, unsigned irqchip, unsigned pin)
 242 {
 243         struct kvm_irq_ack_notifier *kian;
 244         struct hlist_node *n;
 245         int gsi;
 246
 247         rcu_read_lock();
 248         gsi = rcu_dereference(kvm->irq_routing)->chip[irqchip][pin];
 249         if (gsi != -1)
 250                 hlist_for_each_entry_rcu(kian, n, &kvm->irq_ack_notifier_list,
 251                                          link)
 252                         if (kian->gsi == gsi) {
 253                                 rcu_read_unlock();
 254                                 return true;
 255                         }
 256
 257         rcu_read_unlock();
 258
 259         return false;
 260 }
 261 EXPORT_SYMBOL_GPL(kvm_irq_has_notifier);
 262
 263 void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
 264 {
 265         struct kvm_irq_ack_notifier *kian;
 266         struct hlist_node *n;
 267         int gsi;
 268
 269         trace_kvm_ack_irq(irqchip, pin);
 270
 271         rcu_read_lock();
 272         gsi = rcu_dereference(kvm->irq_routing)->chip[irqchip][pin];
 273         if (gsi != -1)
 274                 hlist_for_each_entry_rcu(kian, n, &kvm->irq_ack_notifier_list,
 275                                          link)
 276                         if (kian->gsi == gsi)
 277                                 kian->irq_acked(kian);
 278         rcu_read_unlock();
 279 }
 280
 281 void kvm_register_irq_ack_notifier(struct kvm *kvm,
 282                                    struct kvm_irq_ack_notifier *kian)
 283 {
 284         mutex_lock(&kvm->irq_lock);
 285         hlist_add_head_rcu(&kian->link, &kvm->irq_ack_notifier_list);
 286         mutex_unlock(&kvm->irq_lock);
 287         kvm_ioapic_make_eoibitmap_request(kvm);
 288 }
 289
 290 void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
 291                                     struct kvm_irq_ack_notifier *kian)
 292 {
 293         mutex_lock(&kvm->irq_lock);
 294         hlist_del_init_rcu(&kian->link);
 295         mutex_unlock(&kvm->irq_lock);
 296         synchronize_rcu();
 297         kvm_ioapic_make_eoibitmap_request(kvm);
 298 }
 299
 300 int kvm_request_irq_source_id(struct kvm *kvm)
 301 {
 302         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
 303         int irq_source_id;
 304
 305         mutex_lock(&kvm->irq_lock);
 306         irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
 307
 308         if (irq_source_id >= BITS_PER_LONG) {
 309                 printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
 310                 irq_source_id = -EFAULT;
 311                 goto unlock;
 312         }
 313
 314         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 315 #ifdef CONFIG_X86
 316         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 317 #endif
 318         set_bit(irq_source_id, bitmap);
 319 unlock:
 320         mutex_unlock(&kvm->irq_lock);
 321
 322         return irq_source_id;
 323 }
 324
 325 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 326 {
 327         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 328 #ifdef CONFIG_X86
 329         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 330 #endif
 331
 332         mutex_lock(&kvm->irq_lock);
 333         if (irq_source_id < 0 ||
 334             irq_source_id >= BITS_PER_LONG) {
 335                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 336                 goto unlock;
 337         }
 338         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 339         if (!irqchip_in_kernel(kvm))
 340                 goto unlock;
 341
 342         kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
 343 #ifdef CONFIG_X86
 344         kvm_pic_clear_all(pic_irqchip(kvm), irq_source_id);
 345 #endif
 346 unlock:
 347         mutex_unlock(&kvm->irq_lock);
 348 }
 349
 350 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 351                                     struct kvm_irq_mask_notifier *kimn)
 352 {
 353         mutex_lock(&kvm->irq_lock);
 354         kimn->irq = irq;
 355         hlist_add_head_rcu(&kimn->link, &kvm->mask_notifier_list);
 356         mutex_unlock(&kvm->irq_lock);
 357 }
 358
 359 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 360                                       struct kvm_irq_mask_notifier *kimn)
 361 {
 362         mutex_lock(&kvm->irq_lock);
 363         hlist_del_rcu(&kimn->link);
 364         mutex_unlock(&kvm->irq_lock);
 365         synchronize_rcu();
 366 }
 367
 368 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
 369                              bool mask)
 370 {
 371         struct kvm_irq_mask_notifier *kimn;
 372         struct hlist_node *n;
 373         int gsi;
 374
 375         rcu_read_lock();
 376         gsi = rcu_dereference(kvm->irq_routing)->chip[irqchip][pin];
 377         if (gsi != -1)
 378                 hlist_for_each_entry_rcu(kimn, n, &kvm->mask_notifier_list, link)
 379                         if (kimn->irq == gsi)
 380                                 kimn->func(kimn, mask);
 381         rcu_read_unlock();
 382 }
 383
 384 void kvm_free_irq_routing(struct kvm *kvm)
 385 {
 386         /* Called only during vm destruction. Nobody can use the pointer
 387            at this stage */
 388         kfree(kvm->irq_routing);
 389 }
 390
 391 static int setup_routing_entry(struct kvm_irq_routing_table *rt,
 392                                struct kvm_kernel_irq_routing_entry *e,
 393                                const struct kvm_irq_routing_entry *ue)
 394 {
 395         int r = -EINVAL;
 396         int delta;
 397         unsigned max_pin;
 398         struct kvm_kernel_irq_routing_entry *ei;
 399         struct hlist_node *n;
 400
 401         /*
 402          * Do not allow GSI to be mapped to the same irqchip more than once.
 403          * Allow only one to one mapping between GSI and MSI.
 404          */
 405         hlist_for_each_entry(ei, n, &rt->map[ue->gsi], link)
 406                 if (ei->type == KVM_IRQ_ROUTING_MSI ||
 407                     ue->type == KVM_IRQ_ROUTING_MSI ||
 408                     ue->u.irqchip.irqchip == ei->irqchip.irqchip)
 409                         return r;
 410
 411         e->gsi = ue->gsi;
 412         e->type = ue->type;
 413         switch (ue->type) {
 414         case KVM_IRQ_ROUTING_IRQCHIP:
 415                 delta = 0;
 416                 switch (ue->u.irqchip.irqchip) {
 417                 case KVM_IRQCHIP_PIC_MASTER:
 418                         e->set = kvm_set_pic_irq;
 419                         max_pin = PIC_NUM_PINS;
 420                         break;
 421                 case KVM_IRQCHIP_PIC_SLAVE:
 422                         e->set = kvm_set_pic_irq;
 423                         max_pin = PIC_NUM_PINS;
 424                         delta = 8;
 425                         break;
 426                 case KVM_IRQCHIP_IOAPIC:
 427                         max_pin = KVM_IOAPIC_NUM_PINS;
 428                         e->set = kvm_set_ioapic_irq;
 429                         break;
 430                 default:
 431                         goto out;
 432                 }
 433                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 434                 e->irqchip.pin = ue->u.irqchip.pin + delta;
 435                 if (e->irqchip.pin >= max_pin)
 436                         goto out;
 437                 rt->chip[ue->u.irqchip.irqchip][e->irqchip.pin] = ue->gsi;
 438                 break;
 439         case KVM_IRQ_ROUTING_MSI:
 440                 e->set = kvm_set_msi;
 441                 e->msi.address_lo = ue->u.msi.address_lo;
 442                 e->msi.address_hi = ue->u.msi.address_hi;
 443                 e->msi.data = ue->u.msi.data;
 444                 break;
 445         default:
 446                 goto out;
 447         }
 448
 449         hlist_add_head(&e->link, &rt->map[e->gsi]);
 450         r = 0;
 451 out:
 452         return r;
 453 }
 454
 455
 456 int kvm_set_irq_routing(struct kvm *kvm,
 457                         const struct kvm_irq_routing_entry *ue,
 458                         unsigned nr,
 459                         unsigned flags)
 460 {
 461         struct kvm_irq_routing_table *new, *old;
 462         u32 i, j, nr_rt_entries = 0;
 463         int r;
 464
 465         for (i = 0; i < nr; ++i) {
 466                 if (ue[i].gsi >= KVM_MAX_IRQ_ROUTES)
 467                         return -EINVAL;
 468                 nr_rt_entries = max(nr_rt_entries, ue[i].gsi);
 469         }
 470
 471         nr_rt_entries += 1;
 472
 473         new = kzalloc(sizeof(*new) + (nr_rt_entries * sizeof(struct hlist_head))
 474                       + (nr * sizeof(struct kvm_kernel_irq_routing_entry)),
 475                       GFP_KERNEL);
 476
 477         if (!new)
 478                 return -ENOMEM;
 479
 480         new->rt_entries = (void *)&new->map[nr_rt_entries];
 481
 482         new->nr_rt_entries = nr_rt_entries;
 483         for (i = 0; i < 3; i++)
 484                 for (j = 0; j < KVM_IOAPIC_NUM_PINS; j++)
 485                         new->chip[i][j] = -1;
 486
 487         for (i = 0; i < nr; ++i) {
 488                 r = -EINVAL;
 489                 if (ue->flags)
 490                         goto out;
 491                 r = setup_routing_entry(new, &new->rt_entries[i], ue);
 492                 if (r)
 493                         goto out;
 494                 ++ue;
 495         }
 496
 497         mutex_lock(&kvm->irq_lock);
 498         old = kvm->irq_routing;
 499         kvm_irq_routing_update(kvm, new);
 500         mutex_unlock(&kvm->irq_lock);
 501
 502         synchronize_rcu();
 503
 504         new = old;
 505         r = 0;
 506
 507 out:
 508         kfree(new);
 509         return r;
 510 }
 511
 512 #define IOAPIC_ROUTING_ENTRY(irq) \
 513         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 514           .u.irqchip.irqchip = KVM_IRQCHIP_IOAPIC, .u.irqchip.pin = (irq) }
 515 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 516
 517 #ifdef CONFIG_X86
 518 #  define PIC_ROUTING_ENTRY(irq) \
 519         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 520           .u.irqchip.irqchip = SELECT_PIC(irq), .u.irqchip.pin = (irq) % 8 }
 521 #  define ROUTING_ENTRY2(irq) \
 522         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 523 #else
 524 #  define ROUTING_ENTRY2(irq) \
 525         IOAPIC_ROUTING_ENTRY(irq)
 526 #endif
 527
 528 static const struct kvm_irq_routing_entry default_routing[] = {
 529         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 530         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 531         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 532         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 533         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 534         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 535         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 536         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 537         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 538         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 539         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 540         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 541 #ifdef CONFIG_IA64
 542         ROUTING_ENTRY1(24), ROUTING_ENTRY1(25),
 543         ROUTING_ENTRY1(26), ROUTING_ENTRY1(27),
 544         ROUTING_ENTRY1(28), ROUTING_ENTRY1(29),
 545         ROUTING_ENTRY1(30), ROUTING_ENTRY1(31),
 546         ROUTING_ENTRY1(32), ROUTING_ENTRY1(33),
 547         ROUTING_ENTRY1(34), ROUTING_ENTRY1(35),
 548         ROUTING_ENTRY1(36), ROUTING_ENTRY1(37),
 549         ROUTING_ENTRY1(38), ROUTING_ENTRY1(39),
 550         ROUTING_ENTRY1(40), ROUTING_ENTRY1(41),
 551         ROUTING_ENTRY1(42), ROUTING_ENTRY1(43),
 552         ROUTING_ENTRY1(44), ROUTING_ENTRY1(45),
 553         ROUTING_ENTRY1(46), ROUTING_ENTRY1(47),
 554 #endif
 555 };
 556
 557 int kvm_setup_default_irq_routing(struct kvm *kvm)
 558 {
 559         return kvm_set_irq_routing(kvm, default_routing,
 560                                    ARRAY_SIZE(default_routing), 0);
 561 }