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
 177         trace_kvm_set_irq(irq, level, irq_source_id);
 178
 179         /* Not possible to detect if the guest uses the PIC or the
 180          * IOAPIC.  So set the bit in both. The guest will ignore
 181          * writes to the unused one.
 182          */
 183         rcu_read_lock();
 184         irq_rt = rcu_dereference(kvm->irq_routing);
 185         if (irq < irq_rt->nr_rt_entries)
 186                 hlist_for_each_entry(e, &irq_rt->map[irq], link)
 187                         irq_set[i++] = *e;
 188         rcu_read_unlock();
 189
 190         while(i--) {
 191                 int r;
 192                 r = irq_set[i].set(&irq_set[i], kvm, irq_source_id, level);
 193                 if (r < 0)
 194                         continue;
 195
 196                 ret = r + ((ret < 0) ? 0 : ret);
 197         }
 198
 199         return ret;
 200 }
 201
 202 /*
 203  * Deliver an IRQ in an atomic context if we can, or return a failure,
 204  * user can retry in a process context.
 205  * Return value:
 206  *  -EWOULDBLOCK - Can't deliver in atomic context: retry in a process context.
 207  *  Other values - No need to retry.
 208  */
 209 int kvm_set_irq_inatomic(struct kvm *kvm, int irq_source_id, u32 irq, int level)
 210 {
 211         struct kvm_kernel_irq_routing_entry *e;
 212         int ret = -EINVAL;
 213         struct kvm_irq_routing_table *irq_rt;
 214
 215         trace_kvm_set_irq(irq, level, irq_source_id);
 216
 217         /*
 218          * Injection into either PIC or IOAPIC might need to scan all CPUs,
 219          * which would need to be retried from thread context;  when same GSI
 220          * is connected to both PIC and IOAPIC, we'd have to report a
 221          * partial failure here.
 222          * Since there's no easy way to do this, we only support injecting MSI
 223          * which is limited to 1:1 GSI mapping.
 224          */
 225         rcu_read_lock();
 226         irq_rt = rcu_dereference(kvm->irq_routing);
 227         if (irq < irq_rt->nr_rt_entries)
 228                 hlist_for_each_entry(e, &irq_rt->map[irq], link) {
 229                         if (likely(e->type == KVM_IRQ_ROUTING_MSI))
 230                                 ret = kvm_set_msi_inatomic(e, kvm);
 231                         else
 232                                 ret = -EWOULDBLOCK;
 233                         break;
 234                 }
 235         rcu_read_unlock();
 236         return ret;
 237 }
 238
 239 bool kvm_irq_has_notifier(struct kvm *kvm, unsigned irqchip, unsigned pin)
 240 {
 241         struct kvm_irq_ack_notifier *kian;
 242         int gsi;
 243
 244         rcu_read_lock();
 245         gsi = rcu_dereference(kvm->irq_routing)->chip[irqchip][pin];
 246         if (gsi != -1)
 247                 hlist_for_each_entry_rcu(kian, &kvm->irq_ack_notifier_list,
 248                                          link)
 249                         if (kian->gsi == gsi) {
 250                                 rcu_read_unlock();
 251                                 return true;
 252                         }
 253
 254         rcu_read_unlock();
 255
 256         return false;
 257 }
 258 EXPORT_SYMBOL_GPL(kvm_irq_has_notifier);
 259
 260 void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
 261 {
 262         struct kvm_irq_ack_notifier *kian;
 263         int gsi;
 264
 265         trace_kvm_ack_irq(irqchip, pin);
 266
 267         rcu_read_lock();
 268         gsi = rcu_dereference(kvm->irq_routing)->chip[irqchip][pin];
 269         if (gsi != -1)
 270                 hlist_for_each_entry_rcu(kian, &kvm->irq_ack_notifier_list,
 271                                          link)
 272                         if (kian->gsi == gsi)
 273                                 kian->irq_acked(kian);
 274         rcu_read_unlock();
 275 }
 276
 277 void kvm_register_irq_ack_notifier(struct kvm *kvm,
 278                                    struct kvm_irq_ack_notifier *kian)
 279 {
 280         mutex_lock(&kvm->irq_lock);
 281         hlist_add_head_rcu(&kian->link, &kvm->irq_ack_notifier_list);
 282         mutex_unlock(&kvm->irq_lock);
 283         kvm_ioapic_make_eoibitmap_request(kvm);
 284 }
 285
 286 void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
 287                                     struct kvm_irq_ack_notifier *kian)
 288 {
 289         mutex_lock(&kvm->irq_lock);
 290         hlist_del_init_rcu(&kian->link);
 291         mutex_unlock(&kvm->irq_lock);
 292         synchronize_rcu();
 293         kvm_ioapic_make_eoibitmap_request(kvm);
 294 }
 295
 296 int kvm_request_irq_source_id(struct kvm *kvm)
 297 {
 298         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
 299         int irq_source_id;
 300
 301         mutex_lock(&kvm->irq_lock);
 302         irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
 303
 304         if (irq_source_id >= BITS_PER_LONG) {
 305                 printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
 306                 irq_source_id = -EFAULT;
 307                 goto unlock;
 308         }
 309
 310         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 311 #ifdef CONFIG_X86
 312         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 313 #endif
 314         set_bit(irq_source_id, bitmap);
 315 unlock:
 316         mutex_unlock(&kvm->irq_lock);
 317
 318         return irq_source_id;
 319 }
 320
 321 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 322 {
 323         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 324 #ifdef CONFIG_X86
 325         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 326 #endif
 327
 328         mutex_lock(&kvm->irq_lock);
 329         if (irq_source_id < 0 ||
 330             irq_source_id >= BITS_PER_LONG) {
 331                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 332                 goto unlock;
 333         }
 334         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 335         if (!irqchip_in_kernel(kvm))
 336                 goto unlock;
 337
 338         kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
 339 #ifdef CONFIG_X86
 340         kvm_pic_clear_all(pic_irqchip(kvm), irq_source_id);
 341 #endif
 342 unlock:
 343         mutex_unlock(&kvm->irq_lock);
 344 }
 345
 346 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 347                                     struct kvm_irq_mask_notifier *kimn)
 348 {
 349         mutex_lock(&kvm->irq_lock);
 350         kimn->irq = irq;
 351         hlist_add_head_rcu(&kimn->link, &kvm->mask_notifier_list);
 352         mutex_unlock(&kvm->irq_lock);
 353 }
 354
 355 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 356                                       struct kvm_irq_mask_notifier *kimn)
 357 {
 358         mutex_lock(&kvm->irq_lock);
 359         hlist_del_rcu(&kimn->link);
 360         mutex_unlock(&kvm->irq_lock);
 361         synchronize_rcu();
 362 }
 363
 364 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
 365                              bool mask)
 366 {
 367         struct kvm_irq_mask_notifier *kimn;
 368         int gsi;
 369
 370         rcu_read_lock();
 371         gsi = rcu_dereference(kvm->irq_routing)->chip[irqchip][pin];
 372         if (gsi != -1)
 373                 hlist_for_each_entry_rcu(kimn, &kvm->mask_notifier_list, link)
 374                         if (kimn->irq == gsi)
 375                                 kimn->func(kimn, mask);
 376         rcu_read_unlock();
 377 }
 378
 379 void kvm_free_irq_routing(struct kvm *kvm)
 380 {
 381         /* Called only during vm destruction. Nobody can use the pointer
 382            at this stage */
 383         kfree(kvm->irq_routing);
 384 }
 385
 386 static int setup_routing_entry(struct kvm_irq_routing_table *rt,
 387                                struct kvm_kernel_irq_routing_entry *e,
 388                                const struct kvm_irq_routing_entry *ue)
 389 {
 390         int r = -EINVAL;
 391         int delta;
 392         unsigned max_pin;
 393         struct kvm_kernel_irq_routing_entry *ei;
 394
 395         /*
 396          * Do not allow GSI to be mapped to the same irqchip more than once.
 397          * Allow only one to one mapping between GSI and MSI.
 398          */
 399         hlist_for_each_entry(ei, &rt->map[ue->gsi], link)
 400                 if (ei->type == KVM_IRQ_ROUTING_MSI ||
 401                     ue->type == KVM_IRQ_ROUTING_MSI ||
 402                     ue->u.irqchip.irqchip == ei->irqchip.irqchip)
 403                         return r;
 404
 405         e->gsi = ue->gsi;
 406         e->type = ue->type;
 407         switch (ue->type) {
 408         case KVM_IRQ_ROUTING_IRQCHIP:
 409                 delta = 0;
 410                 switch (ue->u.irqchip.irqchip) {
 411                 case KVM_IRQCHIP_PIC_MASTER:
 412                         e->set = kvm_set_pic_irq;
 413                         max_pin = PIC_NUM_PINS;
 414                         break;
 415                 case KVM_IRQCHIP_PIC_SLAVE:
 416                         e->set = kvm_set_pic_irq;
 417                         max_pin = PIC_NUM_PINS;
 418                         delta = 8;
 419                         break;
 420                 case KVM_IRQCHIP_IOAPIC:
 421                         max_pin = KVM_IOAPIC_NUM_PINS;
 422                         e->set = kvm_set_ioapic_irq;
 423                         break;
 424                 default:
 425                         goto out;
 426                 }
 427                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 428                 e->irqchip.pin = ue->u.irqchip.pin + delta;
 429                 if (e->irqchip.pin >= max_pin)
 430                         goto out;
 431                 rt->chip[ue->u.irqchip.irqchip][e->irqchip.pin] = ue->gsi;
 432                 break;
 433         case KVM_IRQ_ROUTING_MSI:
 434                 e->set = kvm_set_msi;
 435                 e->msi.address_lo = ue->u.msi.address_lo;
 436                 e->msi.address_hi = ue->u.msi.address_hi;
 437                 e->msi.data = ue->u.msi.data;
 438                 break;
 439         default:
 440                 goto out;
 441         }
 442
 443         hlist_add_head(&e->link, &rt->map[e->gsi]);
 444         r = 0;
 445 out:
 446         return r;
 447 }
 448
 449
 450 int kvm_set_irq_routing(struct kvm *kvm,
 451                         const struct kvm_irq_routing_entry *ue,
 452                         unsigned nr,
 453                         unsigned flags)
 454 {
 455         struct kvm_irq_routing_table *new, *old;
 456         u32 i, j, nr_rt_entries = 0;
 457         int r;
 458
 459         for (i = 0; i < nr; ++i) {
 460                 if (ue[i].gsi >= KVM_MAX_IRQ_ROUTES)
 461                         return -EINVAL;
 462                 nr_rt_entries = max(nr_rt_entries, ue[i].gsi);
 463         }
 464
 465         nr_rt_entries += 1;
 466
 467         new = kzalloc(sizeof(*new) + (nr_rt_entries * sizeof(struct hlist_head))
 468                       + (nr * sizeof(struct kvm_kernel_irq_routing_entry)),
 469                       GFP_KERNEL);
 470
 471         if (!new)
 472                 return -ENOMEM;
 473
 474         new->rt_entries = (void *)&new->map[nr_rt_entries];
 475
 476         new->nr_rt_entries = nr_rt_entries;
 477         for (i = 0; i < 3; i++)
 478                 for (j = 0; j < KVM_IOAPIC_NUM_PINS; j++)
 479                         new->chip[i][j] = -1;
 480
 481         for (i = 0; i < nr; ++i) {
 482                 r = -EINVAL;
 483                 if (ue->flags)
 484                         goto out;
 485                 r = setup_routing_entry(new, &new->rt_entries[i], ue);
 486                 if (r)
 487                         goto out;
 488                 ++ue;
 489         }
 490
 491         mutex_lock(&kvm->irq_lock);
 492         old = kvm->irq_routing;
 493         kvm_irq_routing_update(kvm, new);
 494         mutex_unlock(&kvm->irq_lock);
 495
 496         synchronize_rcu();
 497
 498         new = old;
 499         r = 0;
 500
 501 out:
 502         kfree(new);
 503         return r;
 504 }
 505
 506 #define IOAPIC_ROUTING_ENTRY(irq) \
 507         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 508           .u.irqchip.irqchip = KVM_IRQCHIP_IOAPIC, .u.irqchip.pin = (irq) }
 509 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 510
 511 #ifdef CONFIG_X86
 512 #  define PIC_ROUTING_ENTRY(irq) \
 513         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 514           .u.irqchip.irqchip = SELECT_PIC(irq), .u.irqchip.pin = (irq) % 8 }
 515 #  define ROUTING_ENTRY2(irq) \
 516         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 517 #else
 518 #  define ROUTING_ENTRY2(irq) \
 519         IOAPIC_ROUTING_ENTRY(irq)
 520 #endif
 521
 522 static const struct kvm_irq_routing_entry default_routing[] = {
 523         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 524         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 525         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 526         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 527         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 528         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 529         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 530         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 531         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 532         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 533         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 534         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 535 #ifdef CONFIG_IA64
 536         ROUTING_ENTRY1(24), ROUTING_ENTRY1(25),
 537         ROUTING_ENTRY1(26), ROUTING_ENTRY1(27),
 538         ROUTING_ENTRY1(28), ROUTING_ENTRY1(29),
 539         ROUTING_ENTRY1(30), ROUTING_ENTRY1(31),
 540         ROUTING_ENTRY1(32), ROUTING_ENTRY1(33),
 541         ROUTING_ENTRY1(34), ROUTING_ENTRY1(35),
 542         ROUTING_ENTRY1(36), ROUTING_ENTRY1(37),
 543         ROUTING_ENTRY1(38), ROUTING_ENTRY1(39),
 544         ROUTING_ENTRY1(40), ROUTING_ENTRY1(41),
 545         ROUTING_ENTRY1(42), ROUTING_ENTRY1(43),
 546         ROUTING_ENTRY1(44), ROUTING_ENTRY1(45),
 547         ROUTING_ENTRY1(46), ROUTING_ENTRY1(47),
 548 #endif
 549 };
 550
 551 int kvm_setup_default_irq_routing(struct kvm *kvm)
 552 {
 553         return kvm_set_irq_routing(kvm, default_routing,
 554                                    ARRAY_SIZE(default_routing), 0);
 555 }