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