arch/x86/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
  30 #include "irq.h"
  31
  32 #include "ioapic.h"
  33
  34 #include "lapic.h"
  35
  36 #include "hyperv.h"
  37 #include "x86.h"
  38
  39 static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
  40                            struct kvm *kvm, int irq_source_id, int level,
  41                            bool line_status)
  42 {
  43         struct kvm_pic *pic = pic_irqchip(kvm);
  44
  45         /*
  46          * XXX: rejecting pic routes when pic isn't in use would be better,
  47          * but the default routing table is installed while kvm->arch.vpic is
  48          * NULL and KVM_CREATE_IRQCHIP can race with KVM_IRQ_LINE.
  49          */
  50         if (!pic)
  51                 return -1;
  52
  53         return kvm_pic_set_irq(pic, e->irqchip.pin, irq_source_id, level);
  54 }
  55
  56 static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
  57                               struct kvm *kvm, int irq_source_id, int level,
  58                               bool line_status)
  59 {
  60         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
  61
  62         if (!ioapic)
  63                 return -1;
  64
  65         return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, irq_source_id, level,
  66                                 line_status);
  67 }
  68
  69 int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
  70                 struct kvm_lapic_irq *irq, struct dest_map *dest_map)
  71 {
  72         int i, r = -1;
  73         struct kvm_vcpu *vcpu, *lowest = NULL;
  74         unsigned long dest_vcpu_bitmap[BITS_TO_LONGS(KVM_MAX_VCPUS)];
  75         unsigned int dest_vcpus = 0;
  76
  77         if (irq->dest_mode == 0 && irq->dest_id == 0xff &&
  78                         kvm_lowest_prio_delivery(irq)) {
  79                 printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
  80                 irq->delivery_mode = APIC_DM_FIXED;
  81         }
  82
  83         if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
  84                 return r;
  85
  86         memset(dest_vcpu_bitmap, 0, sizeof(dest_vcpu_bitmap));
  87
  88         kvm_for_each_vcpu(i, vcpu, kvm) {
  89                 if (!kvm_apic_present(vcpu))
  90                         continue;
  91
  92                 if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
  93                                         irq->dest_id, irq->dest_mode))
  94                         continue;
  95
  96                 if (!kvm_lowest_prio_delivery(irq)) {
  97                         if (r < 0)
  98                                 r = 0;
  99                         r += kvm_apic_set_irq(vcpu, irq, dest_map);
 100                 } else if (kvm_lapic_enabled(vcpu)) {
 101                         if (!kvm_vector_hashing_enabled()) {
 102                                 if (!lowest)
 103                                         lowest = vcpu;
 104                                 else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
 105                                         lowest = vcpu;
 106                         } else {
 107                                 __set_bit(i, dest_vcpu_bitmap);
 108                                 dest_vcpus++;
 109                         }
 110                 }
 111         }
 112
 113         if (dest_vcpus != 0) {
 114                 int idx = kvm_vector_to_index(irq->vector, dest_vcpus,
 115                                         dest_vcpu_bitmap, KVM_MAX_VCPUS);
 116
 117                 lowest = kvm_get_vcpu(kvm, idx);
 118         }
 119
 120         if (lowest)
 121                 r = kvm_apic_set_irq(lowest, irq, dest_map);
 122
 123         return r;
 124 }
 125
 126 void kvm_set_msi_irq(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *e,
 127                      struct kvm_lapic_irq *irq)
 128 {
 129         trace_kvm_msi_set_irq(e->msi.address_lo | (kvm->arch.x2apic_format ?
 130                                              (u64)e->msi.address_hi << 32 : 0),
 131                               e->msi.data);
 132
 133         irq->dest_id = (e->msi.address_lo &
 134                         MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
 135         if (kvm->arch.x2apic_format)
 136                 irq->dest_id |= MSI_ADDR_EXT_DEST_ID(e->msi.address_hi);
 137         irq->vector = (e->msi.data &
 138                         MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
 139         irq->dest_mode = (1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo;
 140         irq->trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
 141         irq->delivery_mode = e->msi.data & 0x700;
 142         irq->msi_redir_hint = ((e->msi.address_lo
 143                 & MSI_ADDR_REDIRECTION_LOWPRI) > 0);
 144         irq->level = 1;
 145         irq->shorthand = 0;
 146 }
 147 EXPORT_SYMBOL_GPL(kvm_set_msi_irq);
 148
 149 static inline bool kvm_msi_route_invalid(struct kvm *kvm,
 150                 struct kvm_kernel_irq_routing_entry *e)
 151 {
 152         return kvm->arch.x2apic_format && (e->msi.address_hi & 0xff);
 153 }
 154
 155 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
 156                 struct kvm *kvm, int irq_source_id, int level, bool line_status)
 157 {
 158         struct kvm_lapic_irq irq;
 159
 160         if (kvm_msi_route_invalid(kvm, e))
 161                 return -EINVAL;
 162
 163         if (!level)
 164                 return -1;
 165
 166         kvm_set_msi_irq(kvm, e, &irq);
 167
 168         return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
 169 }
 170
 171
 172 static int kvm_hv_set_sint(struct kvm_kernel_irq_routing_entry *e,
 173                     struct kvm *kvm, int irq_source_id, int level,
 174                     bool line_status)
 175 {
 176         if (!level)
 177                 return -1;
 178
 179         return kvm_hv_synic_set_irq(kvm, e->hv_sint.vcpu, e->hv_sint.sint);
 180 }
 181
 182 int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
 183                               struct kvm *kvm, int irq_source_id, int level,
 184                               bool line_status)
 185 {
 186         struct kvm_lapic_irq irq;
 187         int r;
 188
 189         switch (e->type) {
 190         case KVM_IRQ_ROUTING_HV_SINT:
 191                 return kvm_hv_set_sint(e, kvm, irq_source_id, level,
 192                                        line_status);
 193
 194         case KVM_IRQ_ROUTING_MSI:
 195                 if (kvm_msi_route_invalid(kvm, e))
 196                         return -EINVAL;
 197
 198                 kvm_set_msi_irq(kvm, e, &irq);
 199
 200                 if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
 201                         return r;
 202                 break;
 203
 204         default:
 205                 break;
 206         }
 207
 208         return -EWOULDBLOCK;
 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         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 227         set_bit(irq_source_id, bitmap);
 228 unlock:
 229         mutex_unlock(&kvm->irq_lock);
 230
 231         return irq_source_id;
 232 }
 233
 234 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 235 {
 236         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 237         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 238
 239         mutex_lock(&kvm->irq_lock);
 240         if (irq_source_id < 0 ||
 241             irq_source_id >= BITS_PER_LONG) {
 242                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 243                 goto unlock;
 244         }
 245         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 246         if (!ioapic_in_kernel(kvm))
 247                 goto unlock;
 248
 249         kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
 250         kvm_pic_clear_all(pic_irqchip(kvm), irq_source_id);
 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->arch.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_srcu(&kvm->irq_srcu);
 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         int idx, gsi;
 278
 279         idx = srcu_read_lock(&kvm->irq_srcu);
 280         gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
 281         if (gsi != -1)
 282                 hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
 283                         if (kimn->irq == gsi)
 284                                 kimn->func(kimn, mask);
 285         srcu_read_unlock(&kvm->irq_srcu, idx);
 286 }
 287
 288 int kvm_set_routing_entry(struct kvm *kvm,
 289                           struct kvm_kernel_irq_routing_entry *e,
 290                           const struct kvm_irq_routing_entry *ue)
 291 {
 292         int r = -EINVAL;
 293         int delta;
 294         unsigned max_pin;
 295
 296         switch (ue->type) {
 297         case KVM_IRQ_ROUTING_IRQCHIP:
 298                 delta = 0;
 299                 switch (ue->u.irqchip.irqchip) {
 300                 case KVM_IRQCHIP_PIC_MASTER:
 301                         e->set = kvm_set_pic_irq;
 302                         max_pin = PIC_NUM_PINS;
 303                         break;
 304                 case KVM_IRQCHIP_PIC_SLAVE:
 305                         e->set = kvm_set_pic_irq;
 306                         max_pin = PIC_NUM_PINS;
 307                         delta = 8;
 308                         break;
 309                 case KVM_IRQCHIP_IOAPIC:
 310                         max_pin = KVM_IOAPIC_NUM_PINS;
 311                         e->set = kvm_set_ioapic_irq;
 312                         break;
 313                 default:
 314                         goto out;
 315                 }
 316                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 317                 e->irqchip.pin = ue->u.irqchip.pin + delta;
 318                 if (e->irqchip.pin >= max_pin)
 319                         goto out;
 320                 break;
 321         case KVM_IRQ_ROUTING_MSI:
 322                 e->set = kvm_set_msi;
 323                 e->msi.address_lo = ue->u.msi.address_lo;
 324                 e->msi.address_hi = ue->u.msi.address_hi;
 325                 e->msi.data = ue->u.msi.data;
 326
 327                 if (kvm_msi_route_invalid(kvm, e))
 328                         goto out;
 329                 break;
 330         case KVM_IRQ_ROUTING_HV_SINT:
 331                 e->set = kvm_hv_set_sint;
 332                 e->hv_sint.vcpu = ue->u.hv_sint.vcpu;
 333                 e->hv_sint.sint = ue->u.hv_sint.sint;
 334                 break;
 335         default:
 336                 goto out;
 337         }
 338
 339         r = 0;
 340 out:
 341         return r;
 342 }
 343
 344 bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
 345                              struct kvm_vcpu **dest_vcpu)
 346 {
 347         int i, r = 0;
 348         struct kvm_vcpu *vcpu;
 349
 350         if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
 351                 return true;
 352
 353         kvm_for_each_vcpu(i, vcpu, kvm) {
 354                 if (!kvm_apic_present(vcpu))
 355                         continue;
 356
 357                 if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand,
 358                                         irq->dest_id, irq->dest_mode))
 359                         continue;
 360
 361                 if (++r == 2)
 362                         return false;
 363
 364                 *dest_vcpu = vcpu;
 365         }
 366
 367         return r == 1;
 368 }
 369 EXPORT_SYMBOL_GPL(kvm_intr_is_single_vcpu);
 370
 371 #define IOAPIC_ROUTING_ENTRY(irq) \
 372         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 373           .u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
 374 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 375
 376 #define PIC_ROUTING_ENTRY(irq) \
 377         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 378           .u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
 379 #define ROUTING_ENTRY2(irq) \
 380         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 381
 382 static const struct kvm_irq_routing_entry default_routing[] = {
 383         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 384         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 385         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 386         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 387         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 388         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 389         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 390         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 391         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 392         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 393         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 394         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 395 };
 396
 397 int kvm_setup_default_irq_routing(struct kvm *kvm)
 398 {
 399         return kvm_set_irq_routing(kvm, default_routing,
 400                                    ARRAY_SIZE(default_routing), 0);
 401 }
 402
 403 static const struct kvm_irq_routing_entry empty_routing[] = {};
 404
 405 int kvm_setup_empty_irq_routing(struct kvm *kvm)
 406 {
 407         return kvm_set_irq_routing(kvm, empty_routing, 0, 0);
 408 }
 409
 410 void kvm_arch_post_irq_routing_update(struct kvm *kvm)
 411 {
 412         if (ioapic_in_kernel(kvm) || !irqchip_in_kernel(kvm))
 413                 return;
 414         kvm_make_scan_ioapic_request(kvm);
 415 }
 416
 417 void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu,
 418                             ulong *ioapic_handled_vectors)
 419 {
 420         struct kvm *kvm = vcpu->kvm;
 421         struct kvm_kernel_irq_routing_entry *entry;
 422         struct kvm_irq_routing_table *table;
 423         u32 i, nr_ioapic_pins;
 424         int idx;
 425
 426         idx = srcu_read_lock(&kvm->irq_srcu);
 427         table = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
 428         nr_ioapic_pins = min_t(u32, table->nr_rt_entries,
 429                                kvm->arch.nr_reserved_ioapic_pins);
 430         for (i = 0; i < nr_ioapic_pins; ++i) {
 431                 hlist_for_each_entry(entry, &table->map[i], link) {
 432                         struct kvm_lapic_irq irq;
 433
 434                         if (entry->type != KVM_IRQ_ROUTING_MSI)
 435                                 continue;
 436
 437                         kvm_set_msi_irq(vcpu->kvm, entry, &irq);
 438
 439                         if (irq.level && kvm_apic_match_dest(vcpu, NULL, 0,
 440                                                 irq.dest_id, irq.dest_mode))
 441                                 __set_bit(irq.vector, ioapic_handled_vectors);
 442                 }
 443         }
 444         srcu_read_unlock(&kvm->irq_srcu, idx);
 445 }
 446
 447 void kvm_arch_irq_routing_update(struct kvm *kvm)
 448 {
 449         kvm_hv_irq_routing_update(kvm);
 450 }