arch/x86/kvm/irq_comm.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * irq_comm.c: Common API for in kernel interrupt controller
   4  * Copyright (c) 2007, Intel Corporation.
   5  *
   6  * Authors:
   7  *   Yaozu (Eddie) Dong <Eddie.dong@intel.com>
   8  *
   9  * Copyright 2010 Red Hat, Inc. and/or its affiliates.
  10  */
  11
  12 #include <linux/kvm_host.h>
  13 #include <linux/slab.h>
  14 #include <linux/export.h>
  15 #include <linux/rculist.h>
  16
  17 #include <trace/events/kvm.h>
  18
  19 #include "irq.h"
  20
  21 #include "ioapic.h"
  22
  23 #include "lapic.h"
  24
  25 #include "hyperv.h"
  26 #include "x86.h"
  27 #include "xen.h"
  28
  29 static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
  30                            struct kvm *kvm, int irq_source_id, int level,
  31                            bool line_status)
  32 {
  33         struct kvm_pic *pic = kvm->arch.vpic;
  34         return kvm_pic_set_irq(pic, e->irqchip.pin, irq_source_id, level);
  35 }
  36
  37 static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
  38                               struct kvm *kvm, int irq_source_id, int level,
  39                               bool line_status)
  40 {
  41         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
  42         return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, irq_source_id, level,
  43                                 line_status);
  44 }
  45
  46 int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
  47                 struct kvm_lapic_irq *irq, struct dest_map *dest_map)
  48 {
  49         int r = -1;
  50         struct kvm_vcpu *vcpu, *lowest = NULL;
  51         unsigned long i, dest_vcpu_bitmap[BITS_TO_LONGS(KVM_MAX_VCPUS)];
  52         unsigned int dest_vcpus = 0;
  53
  54         if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
  55                 return r;
  56
  57         if (irq->dest_mode == APIC_DEST_PHYSICAL &&
  58             irq->dest_id == 0xff && kvm_lowest_prio_delivery(irq)) {
  59                 printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
  60                 irq->delivery_mode = APIC_DM_FIXED;
  61         }
  62
  63         memset(dest_vcpu_bitmap, 0, sizeof(dest_vcpu_bitmap));
  64
  65         kvm_for_each_vcpu(i, vcpu, kvm) {
  66                 if (!kvm_apic_present(vcpu))
  67                         continue;
  68
  69                 if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
  70                                         irq->dest_id, irq->dest_mode))
  71                         continue;
  72
  73                 if (!kvm_lowest_prio_delivery(irq)) {
  74                         if (r < 0)
  75                                 r = 0;
  76                         r += kvm_apic_set_irq(vcpu, irq, dest_map);
  77                 } else if (kvm_apic_sw_enabled(vcpu->arch.apic)) {
  78                         if (!kvm_vector_hashing_enabled()) {
  79                                 if (!lowest)
  80                                         lowest = vcpu;
  81                                 else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
  82                                         lowest = vcpu;
  83                         } else {
  84                                 __set_bit(i, dest_vcpu_bitmap);
  85                                 dest_vcpus++;
  86                         }
  87                 }
  88         }
  89
  90         if (dest_vcpus != 0) {
  91                 int idx = kvm_vector_to_index(irq->vector, dest_vcpus,
  92                                         dest_vcpu_bitmap, KVM_MAX_VCPUS);
  93
  94                 lowest = kvm_get_vcpu(kvm, idx);
  95         }
  96
  97         if (lowest)
  98                 r = kvm_apic_set_irq(lowest, irq, dest_map);
  99
 100         return r;
 101 }
 102
 103 void kvm_set_msi_irq(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *e,
 104                      struct kvm_lapic_irq *irq)
 105 {
 106         struct msi_msg msg = { .address_lo = e->msi.address_lo,
 107                                .address_hi = e->msi.address_hi,
 108                                .data = e->msi.data };
 109
 110         trace_kvm_msi_set_irq(msg.address_lo | (kvm->arch.x2apic_format ?
 111                               (u64)msg.address_hi << 32 : 0), msg.data);
 112
 113         irq->dest_id = x86_msi_msg_get_destid(&msg, kvm->arch.x2apic_format);
 114         irq->vector = msg.arch_data.vector;
 115         irq->dest_mode = kvm_lapic_irq_dest_mode(msg.arch_addr_lo.dest_mode_logical);
 116         irq->trig_mode = msg.arch_data.is_level;
 117         irq->delivery_mode = msg.arch_data.delivery_mode << 8;
 118         irq->msi_redir_hint = msg.arch_addr_lo.redirect_hint;
 119         irq->level = 1;
 120         irq->shorthand = APIC_DEST_NOSHORT;
 121 }
 122 EXPORT_SYMBOL_GPL(kvm_set_msi_irq);
 123
 124 static inline bool kvm_msi_route_invalid(struct kvm *kvm,
 125                 struct kvm_kernel_irq_routing_entry *e)
 126 {
 127         return kvm->arch.x2apic_format && (e->msi.address_hi & 0xff);
 128 }
 129
 130 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
 131                 struct kvm *kvm, int irq_source_id, int level, bool line_status)
 132 {
 133         struct kvm_lapic_irq irq;
 134
 135         if (kvm_msi_route_invalid(kvm, e))
 136                 return -EINVAL;
 137
 138         if (!level)
 139                 return -1;
 140
 141         kvm_set_msi_irq(kvm, e, &irq);
 142
 143         return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
 144 }
 145
 146
 147 static int kvm_hv_set_sint(struct kvm_kernel_irq_routing_entry *e,
 148                     struct kvm *kvm, int irq_source_id, int level,
 149                     bool line_status)
 150 {
 151         if (!level)
 152                 return -1;
 153
 154         return kvm_hv_synic_set_irq(kvm, e->hv_sint.vcpu, e->hv_sint.sint);
 155 }
 156
 157 int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
 158                               struct kvm *kvm, int irq_source_id, int level,
 159                               bool line_status)
 160 {
 161         struct kvm_lapic_irq irq;
 162         int r;
 163
 164         switch (e->type) {
 165         case KVM_IRQ_ROUTING_HV_SINT:
 166                 return kvm_hv_set_sint(e, kvm, irq_source_id, level,
 167                                        line_status);
 168
 169         case KVM_IRQ_ROUTING_MSI:
 170                 if (kvm_msi_route_invalid(kvm, e))
 171                         return -EINVAL;
 172
 173                 kvm_set_msi_irq(kvm, e, &irq);
 174
 175                 if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
 176                         return r;
 177                 break;
 178
 179 #ifdef CONFIG_KVM_XEN
 180         case KVM_IRQ_ROUTING_XEN_EVTCHN:
 181                 if (!level)
 182                         return -1;
 183
 184                 return kvm_xen_set_evtchn_fast(e, kvm);
 185 #endif
 186         default:
 187                 break;
 188         }
 189
 190         return -EWOULDBLOCK;
 191 }
 192
 193 int kvm_request_irq_source_id(struct kvm *kvm)
 194 {
 195         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
 196         int irq_source_id;
 197
 198         mutex_lock(&kvm->irq_lock);
 199         irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
 200
 201         if (irq_source_id >= BITS_PER_LONG) {
 202                 printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
 203                 irq_source_id = -EFAULT;
 204                 goto unlock;
 205         }
 206
 207         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 208         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 209         set_bit(irq_source_id, bitmap);
 210 unlock:
 211         mutex_unlock(&kvm->irq_lock);
 212
 213         return irq_source_id;
 214 }
 215
 216 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 217 {
 218         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 219         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 220
 221         mutex_lock(&kvm->irq_lock);
 222         if (irq_source_id < 0 ||
 223             irq_source_id >= BITS_PER_LONG) {
 224                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 225                 goto unlock;
 226         }
 227         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 228         if (!irqchip_kernel(kvm))
 229                 goto unlock;
 230
 231         kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
 232         kvm_pic_clear_all(kvm->arch.vpic, irq_source_id);
 233 unlock:
 234         mutex_unlock(&kvm->irq_lock);
 235 }
 236
 237 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 238                                     struct kvm_irq_mask_notifier *kimn)
 239 {
 240         mutex_lock(&kvm->irq_lock);
 241         kimn->irq = irq;
 242         hlist_add_head_rcu(&kimn->link, &kvm->arch.mask_notifier_list);
 243         mutex_unlock(&kvm->irq_lock);
 244 }
 245
 246 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 247                                       struct kvm_irq_mask_notifier *kimn)
 248 {
 249         mutex_lock(&kvm->irq_lock);
 250         hlist_del_rcu(&kimn->link);
 251         mutex_unlock(&kvm->irq_lock);
 252         synchronize_srcu(&kvm->irq_srcu);
 253 }
 254
 255 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
 256                              bool mask)
 257 {
 258         struct kvm_irq_mask_notifier *kimn;
 259         int idx, gsi;
 260
 261         idx = srcu_read_lock(&kvm->irq_srcu);
 262         gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
 263         if (gsi != -1)
 264                 hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
 265                         if (kimn->irq == gsi)
 266                                 kimn->func(kimn, mask);
 267         srcu_read_unlock(&kvm->irq_srcu, idx);
 268 }
 269
 270 bool kvm_arch_can_set_irq_routing(struct kvm *kvm)
 271 {
 272         return irqchip_in_kernel(kvm);
 273 }
 274
 275 int kvm_set_routing_entry(struct kvm *kvm,
 276                           struct kvm_kernel_irq_routing_entry *e,
 277                           const struct kvm_irq_routing_entry *ue)
 278 {
 279         /* We can't check irqchip_in_kernel() here as some callers are
 280          * currently initializing the irqchip. Other callers should therefore
 281          * check kvm_arch_can_set_irq_routing() before calling this function.
 282          */
 283         switch (ue->type) {
 284         case KVM_IRQ_ROUTING_IRQCHIP:
 285                 if (irqchip_split(kvm))
 286                         return -EINVAL;
 287                 e->irqchip.pin = ue->u.irqchip.pin;
 288                 switch (ue->u.irqchip.irqchip) {
 289                 case KVM_IRQCHIP_PIC_SLAVE:
 290                         e->irqchip.pin += PIC_NUM_PINS / 2;
 291                         fallthrough;
 292                 case KVM_IRQCHIP_PIC_MASTER:
 293                         if (ue->u.irqchip.pin >= PIC_NUM_PINS / 2)
 294                                 return -EINVAL;
 295                         e->set = kvm_set_pic_irq;
 296                         break;
 297                 case KVM_IRQCHIP_IOAPIC:
 298                         if (ue->u.irqchip.pin >= KVM_IOAPIC_NUM_PINS)
 299                                 return -EINVAL;
 300                         e->set = kvm_set_ioapic_irq;
 301                         break;
 302                 default:
 303                         return -EINVAL;
 304                 }
 305                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 306                 break;
 307         case KVM_IRQ_ROUTING_MSI:
 308                 e->set = kvm_set_msi;
 309                 e->msi.address_lo = ue->u.msi.address_lo;
 310                 e->msi.address_hi = ue->u.msi.address_hi;
 311                 e->msi.data = ue->u.msi.data;
 312
 313                 if (kvm_msi_route_invalid(kvm, e))
 314                         return -EINVAL;
 315                 break;
 316         case KVM_IRQ_ROUTING_HV_SINT:
 317                 e->set = kvm_hv_set_sint;
 318                 e->hv_sint.vcpu = ue->u.hv_sint.vcpu;
 319                 e->hv_sint.sint = ue->u.hv_sint.sint;
 320                 break;
 321 #ifdef CONFIG_KVM_XEN
 322         case KVM_IRQ_ROUTING_XEN_EVTCHN:
 323                 return kvm_xen_setup_evtchn(kvm, e, ue);
 324 #endif
 325         default:
 326                 return -EINVAL;
 327         }
 328
 329         return 0;
 330 }
 331
 332 bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
 333                              struct kvm_vcpu **dest_vcpu)
 334 {
 335         int r = 0;
 336         unsigned long i;
 337         struct kvm_vcpu *vcpu;
 338
 339         if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
 340                 return true;
 341
 342         kvm_for_each_vcpu(i, vcpu, kvm) {
 343                 if (!kvm_apic_present(vcpu))
 344                         continue;
 345
 346                 if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand,
 347                                         irq->dest_id, irq->dest_mode))
 348                         continue;
 349
 350                 if (++r == 2)
 351                         return false;
 352
 353                 *dest_vcpu = vcpu;
 354         }
 355
 356         return r == 1;
 357 }
 358 EXPORT_SYMBOL_GPL(kvm_intr_is_single_vcpu);
 359
 360 #define IOAPIC_ROUTING_ENTRY(irq) \
 361         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 362           .u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
 363 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 364
 365 #define PIC_ROUTING_ENTRY(irq) \
 366         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 367           .u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
 368 #define ROUTING_ENTRY2(irq) \
 369         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 370
 371 static const struct kvm_irq_routing_entry default_routing[] = {
 372         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 373         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 374         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 375         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 376         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 377         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 378         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 379         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 380         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 381         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 382         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 383         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 384 };
 385
 386 int kvm_setup_default_irq_routing(struct kvm *kvm)
 387 {
 388         return kvm_set_irq_routing(kvm, default_routing,
 389                                    ARRAY_SIZE(default_routing), 0);
 390 }
 391
 392 static const struct kvm_irq_routing_entry empty_routing[] = {};
 393
 394 int kvm_setup_empty_irq_routing(struct kvm *kvm)
 395 {
 396         return kvm_set_irq_routing(kvm, empty_routing, 0, 0);
 397 }
 398
 399 void kvm_arch_post_irq_routing_update(struct kvm *kvm)
 400 {
 401         if (!irqchip_split(kvm))
 402                 return;
 403         kvm_make_scan_ioapic_request(kvm);
 404 }
 405
 406 void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu,
 407                             ulong *ioapic_handled_vectors)
 408 {
 409         struct kvm *kvm = vcpu->kvm;
 410         struct kvm_kernel_irq_routing_entry *entry;
 411         struct kvm_irq_routing_table *table;
 412         u32 i, nr_ioapic_pins;
 413         int idx;
 414
 415         idx = srcu_read_lock(&kvm->irq_srcu);
 416         table = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
 417         nr_ioapic_pins = min_t(u32, table->nr_rt_entries,
 418                                kvm->arch.nr_reserved_ioapic_pins);
 419         for (i = 0; i < nr_ioapic_pins; ++i) {
 420                 hlist_for_each_entry(entry, &table->map[i], link) {
 421                         struct kvm_lapic_irq irq;
 422
 423                         if (entry->type != KVM_IRQ_ROUTING_MSI)
 424                                 continue;
 425
 426                         kvm_set_msi_irq(vcpu->kvm, entry, &irq);
 427
 428                         if (irq.trig_mode &&
 429                             kvm_apic_match_dest(vcpu, NULL, APIC_DEST_NOSHORT,
 430                                                 irq.dest_id, irq.dest_mode))
 431                                 __set_bit(irq.vector, ioapic_handled_vectors);
 432                 }
 433         }
 434         srcu_read_unlock(&kvm->irq_srcu, idx);
 435 }
 436
 437 void kvm_arch_irq_routing_update(struct kvm *kvm)
 438 {
 439         kvm_hv_irq_routing_update(kvm);
 440 }