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 <linux/rculist.h>
  27
  28 #include <trace/events/kvm.h>
  29
  30 #include <asm/msidef.h>
  31
  32 #include "irq.h"
  33
  34 #include "ioapic.h"
  35
  36 #include "lapic.h"
  37
  38 #include "hyperv.h"
  39 #include "x86.h"
  40
  41 static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
  42                            struct kvm *kvm, int irq_source_id, int level,
  43                            bool line_status)
  44 {
  45         struct kvm_pic *pic = kvm->arch.vpic;
  46         return kvm_pic_set_irq(pic, e->irqchip.pin, irq_source_id, level);
  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 int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
  59                 struct kvm_lapic_irq *irq, struct dest_map *dest_map)
  60 {
  61         int i, r = -1;
  62         struct kvm_vcpu *vcpu, *lowest = NULL;
  63         unsigned long dest_vcpu_bitmap[BITS_TO_LONGS(KVM_MAX_VCPUS)];
  64         unsigned int dest_vcpus = 0;
  65
  66         if (irq->dest_mode == 0 && irq->dest_id == 0xff &&
  67                         kvm_lowest_prio_delivery(irq)) {
  68                 printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
  69                 irq->delivery_mode = APIC_DM_FIXED;
  70         }
  71
  72         if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
  73                 return r;
  74
  75         memset(dest_vcpu_bitmap, 0, sizeof(dest_vcpu_bitmap));
  76
  77         kvm_for_each_vcpu(i, vcpu, kvm) {
  78                 if (!kvm_apic_present(vcpu))
  79                         continue;
  80
  81                 if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
  82                                         irq->dest_id, irq->dest_mode))
  83                         continue;
  84
  85                 if (!kvm_lowest_prio_delivery(irq)) {
  86                         if (r < 0)
  87                                 r = 0;
  88                         r += kvm_apic_set_irq(vcpu, irq, dest_map);
  89                 } else if (kvm_lapic_enabled(vcpu)) {
  90                         if (!kvm_vector_hashing_enabled()) {
  91                                 if (!lowest)
  92                                         lowest = vcpu;
  93                                 else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
  94                                         lowest = vcpu;
  95                         } else {
  96                                 __set_bit(i, dest_vcpu_bitmap);
  97                                 dest_vcpus++;
  98                         }
  99                 }
 100         }
 101
 102         if (dest_vcpus != 0) {
 103                 int idx = kvm_vector_to_index(irq->vector, dest_vcpus,
 104                                         dest_vcpu_bitmap, KVM_MAX_VCPUS);
 105
 106                 lowest = kvm_get_vcpu(kvm, idx);
 107         }
 108
 109         if (lowest)
 110                 r = kvm_apic_set_irq(lowest, irq, dest_map);
 111
 112         return r;
 113 }
 114
 115 void kvm_set_msi_irq(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *e,
 116                      struct kvm_lapic_irq *irq)
 117 {
 118         trace_kvm_msi_set_irq(e->msi.address_lo | (kvm->arch.x2apic_format ?
 119                                              (u64)e->msi.address_hi << 32 : 0),
 120                               e->msi.data);
 121
 122         irq->dest_id = (e->msi.address_lo &
 123                         MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
 124         if (kvm->arch.x2apic_format)
 125                 irq->dest_id |= MSI_ADDR_EXT_DEST_ID(e->msi.address_hi);
 126         irq->vector = (e->msi.data &
 127                         MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
 128         irq->dest_mode = (1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo;
 129         irq->trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
 130         irq->delivery_mode = e->msi.data & 0x700;
 131         irq->msi_redir_hint = ((e->msi.address_lo
 132                 & MSI_ADDR_REDIRECTION_LOWPRI) > 0);
 133         irq->level = 1;
 134         irq->shorthand = 0;
 135 }
 136 EXPORT_SYMBOL_GPL(kvm_set_msi_irq);
 137
 138 static inline bool kvm_msi_route_invalid(struct kvm *kvm,
 139                 struct kvm_kernel_irq_routing_entry *e)
 140 {
 141         return kvm->arch.x2apic_format && (e->msi.address_hi & 0xff);
 142 }
 143
 144 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
 145                 struct kvm *kvm, int irq_source_id, int level, bool line_status)
 146 {
 147         struct kvm_lapic_irq irq;
 148
 149         if (kvm_msi_route_invalid(kvm, e))
 150                 return -EINVAL;
 151
 152         if (!level)
 153                 return -1;
 154
 155         kvm_set_msi_irq(kvm, e, &irq);
 156
 157         return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
 158 }
 159
 160
 161 static int kvm_hv_set_sint(struct kvm_kernel_irq_routing_entry *e,
 162                     struct kvm *kvm, int irq_source_id, int level,
 163                     bool line_status)
 164 {
 165         if (!level)
 166                 return -1;
 167
 168         return kvm_hv_synic_set_irq(kvm, e->hv_sint.vcpu, e->hv_sint.sint);
 169 }
 170
 171 int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
 172                               struct kvm *kvm, int irq_source_id, int level,
 173                               bool line_status)
 174 {
 175         struct kvm_lapic_irq irq;
 176         int r;
 177
 178         switch (e->type) {
 179         case KVM_IRQ_ROUTING_HV_SINT:
 180                 return kvm_hv_set_sint(e, kvm, irq_source_id, level,
 181                                        line_status);
 182
 183         case KVM_IRQ_ROUTING_MSI:
 184                 if (kvm_msi_route_invalid(kvm, e))
 185                         return -EINVAL;
 186
 187                 kvm_set_msi_irq(kvm, e, &irq);
 188
 189                 if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
 190                         return r;
 191                 break;
 192
 193         default:
 194                 break;
 195         }
 196
 197         return -EWOULDBLOCK;
 198 }
 199
 200 int kvm_request_irq_source_id(struct kvm *kvm)
 201 {
 202         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
 203         int irq_source_id;
 204
 205         mutex_lock(&kvm->irq_lock);
 206         irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
 207
 208         if (irq_source_id >= BITS_PER_LONG) {
 209                 printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
 210                 irq_source_id = -EFAULT;
 211                 goto unlock;
 212         }
 213
 214         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 215         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 216         set_bit(irq_source_id, bitmap);
 217 unlock:
 218         mutex_unlock(&kvm->irq_lock);
 219
 220         return irq_source_id;
 221 }
 222
 223 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 224 {
 225         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 226         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 227
 228         mutex_lock(&kvm->irq_lock);
 229         if (irq_source_id < 0 ||
 230             irq_source_id >= BITS_PER_LONG) {
 231                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 232                 goto unlock;
 233         }
 234         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 235         if (!irqchip_kernel(kvm))
 236                 goto unlock;
 237
 238         kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
 239         kvm_pic_clear_all(kvm->arch.vpic, irq_source_id);
 240 unlock:
 241         mutex_unlock(&kvm->irq_lock);
 242 }
 243
 244 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 245                                     struct kvm_irq_mask_notifier *kimn)
 246 {
 247         mutex_lock(&kvm->irq_lock);
 248         kimn->irq = irq;
 249         hlist_add_head_rcu(&kimn->link, &kvm->arch.mask_notifier_list);
 250         mutex_unlock(&kvm->irq_lock);
 251 }
 252
 253 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 254                                       struct kvm_irq_mask_notifier *kimn)
 255 {
 256         mutex_lock(&kvm->irq_lock);
 257         hlist_del_rcu(&kimn->link);
 258         mutex_unlock(&kvm->irq_lock);
 259         synchronize_srcu(&kvm->irq_srcu);
 260 }
 261
 262 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
 263                              bool mask)
 264 {
 265         struct kvm_irq_mask_notifier *kimn;
 266         int idx, gsi;
 267
 268         idx = srcu_read_lock(&kvm->irq_srcu);
 269         gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
 270         if (gsi != -1)
 271                 hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
 272                         if (kimn->irq == gsi)
 273                                 kimn->func(kimn, mask);
 274         srcu_read_unlock(&kvm->irq_srcu, idx);
 275 }
 276
 277 bool kvm_arch_can_set_irq_routing(struct kvm *kvm)
 278 {
 279         return irqchip_in_kernel(kvm);
 280 }
 281
 282 int kvm_set_routing_entry(struct kvm *kvm,
 283                           struct kvm_kernel_irq_routing_entry *e,
 284                           const struct kvm_irq_routing_entry *ue)
 285 {
 286         /* We can't check irqchip_in_kernel() here as some callers are
 287          * currently inititalizing the irqchip. Other callers should therefore
 288          * check kvm_arch_can_set_irq_routing() before calling this function.
 289          */
 290         switch (ue->type) {
 291         case KVM_IRQ_ROUTING_IRQCHIP:
 292                 if (irqchip_split(kvm))
 293                         return -EINVAL;
 294                 e->irqchip.pin = ue->u.irqchip.pin;
 295                 switch (ue->u.irqchip.irqchip) {
 296                 case KVM_IRQCHIP_PIC_SLAVE:
 297                         e->irqchip.pin += PIC_NUM_PINS / 2;
 298                         /* fall through */
 299                 case KVM_IRQCHIP_PIC_MASTER:
 300                         if (ue->u.irqchip.pin >= PIC_NUM_PINS / 2)
 301                                 return -EINVAL;
 302                         e->set = kvm_set_pic_irq;
 303                         break;
 304                 case KVM_IRQCHIP_IOAPIC:
 305                         if (ue->u.irqchip.pin >= KVM_IOAPIC_NUM_PINS)
 306                                 return -EINVAL;
 307                         e->set = kvm_set_ioapic_irq;
 308                         break;
 309                 default:
 310                         return -EINVAL;
 311                 }
 312                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 313                 break;
 314         case KVM_IRQ_ROUTING_MSI:
 315                 e->set = kvm_set_msi;
 316                 e->msi.address_lo = ue->u.msi.address_lo;
 317                 e->msi.address_hi = ue->u.msi.address_hi;
 318                 e->msi.data = ue->u.msi.data;
 319
 320                 if (kvm_msi_route_invalid(kvm, e))
 321                         return -EINVAL;
 322                 break;
 323         case KVM_IRQ_ROUTING_HV_SINT:
 324                 e->set = kvm_hv_set_sint;
 325                 e->hv_sint.vcpu = ue->u.hv_sint.vcpu;
 326                 e->hv_sint.sint = ue->u.hv_sint.sint;
 327                 break;
 328         default:
 329                 return -EINVAL;
 330         }
 331
 332         return 0;
 333 }
 334
 335 bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
 336                              struct kvm_vcpu **dest_vcpu)
 337 {
 338         int i, r = 0;
 339         struct kvm_vcpu *vcpu;
 340
 341         if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
 342                 return true;
 343
 344         kvm_for_each_vcpu(i, vcpu, kvm) {
 345                 if (!kvm_apic_present(vcpu))
 346                         continue;
 347
 348                 if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand,
 349                                         irq->dest_id, irq->dest_mode))
 350                         continue;
 351
 352                 if (++r == 2)
 353                         return false;
 354
 355                 *dest_vcpu = vcpu;
 356         }
 357
 358         return r == 1;
 359 }
 360 EXPORT_SYMBOL_GPL(kvm_intr_is_single_vcpu);
 361
 362 #define IOAPIC_ROUTING_ENTRY(irq) \
 363         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 364           .u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
 365 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 366
 367 #define PIC_ROUTING_ENTRY(irq) \
 368         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 369           .u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
 370 #define ROUTING_ENTRY2(irq) \
 371         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 372
 373 static const struct kvm_irq_routing_entry default_routing[] = {
 374         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 375         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 376         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 377         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 378         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 379         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 380         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 381         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 382         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 383         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 384         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 385         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 386 };
 387
 388 int kvm_setup_default_irq_routing(struct kvm *kvm)
 389 {
 390         return kvm_set_irq_routing(kvm, default_routing,
 391                                    ARRAY_SIZE(default_routing), 0);
 392 }
 393
 394 static const struct kvm_irq_routing_entry empty_routing[] = {};
 395
 396 int kvm_setup_empty_irq_routing(struct kvm *kvm)
 397 {
 398         return kvm_set_irq_routing(kvm, empty_routing, 0, 0);
 399 }
 400
 401 void kvm_arch_post_irq_routing_update(struct kvm *kvm)
 402 {
 403         if (!irqchip_split(kvm))
 404                 return;
 405         kvm_make_scan_ioapic_request(kvm);
 406 }
 407
 408 void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu,
 409                             ulong *ioapic_handled_vectors)
 410 {
 411         struct kvm *kvm = vcpu->kvm;
 412         struct kvm_kernel_irq_routing_entry *entry;
 413         struct kvm_irq_routing_table *table;
 414         u32 i, nr_ioapic_pins;
 415         int idx;
 416
 417         idx = srcu_read_lock(&kvm->irq_srcu);
 418         table = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
 419         nr_ioapic_pins = min_t(u32, table->nr_rt_entries,
 420                                kvm->arch.nr_reserved_ioapic_pins);
 421         for (i = 0; i < nr_ioapic_pins; ++i) {
 422                 hlist_for_each_entry(entry, &table->map[i], link) {
 423                         struct kvm_lapic_irq irq;
 424
 425                         if (entry->type != KVM_IRQ_ROUTING_MSI)
 426                                 continue;
 427
 428                         kvm_set_msi_irq(vcpu->kvm, entry, &irq);
 429
 430                         if (irq.level && kvm_apic_match_dest(vcpu, NULL, 0,
 431                                                 irq.dest_id, irq.dest_mode))
 432                                 __set_bit(irq.vector, ioapic_handled_vectors);
 433                 }
 434         }
 435         srcu_read_unlock(&kvm->irq_srcu, idx);
 436 }
 437
 438 void kvm_arch_irq_routing_update(struct kvm *kvm)
 439 {
 440         kvm_hv_irq_routing_update(kvm);
 441 }