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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  12
  13 #include <linux/kvm_host.h>
  14 #include <linux/slab.h>
  15 #include <linux/export.h>
  16 #include <linux/rculist.h>
  17
  18 #include <trace/events/kvm.h>
  19
  20 #include "irq.h"
  21
  22 #include "ioapic.h"
  23
  24 #include "lapic.h"
  25
  26 #include "hyperv.h"
  27 #include "x86.h"
  28 #include "xen.h"
  29
  30 static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
  31                            struct kvm *kvm, int irq_source_id, int level,
  32                            bool line_status)
  33 {
  34         struct kvm_pic *pic = kvm->arch.vpic;
  35         return kvm_pic_set_irq(pic, e->irqchip.pin, irq_source_id, level);
  36 }
  37
  38 static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
  39                               struct kvm *kvm, int irq_source_id, int level,
  40                               bool line_status)
  41 {
  42         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
  43         return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, irq_source_id, level,
  44                                 line_status);
  45 }
  46
  47 int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
  48                 struct kvm_lapic_irq *irq, struct dest_map *dest_map)
  49 {
  50         int r = -1;
  51         struct kvm_vcpu *vcpu, *lowest = NULL;
  52         unsigned long i, dest_vcpu_bitmap[BITS_TO_LONGS(KVM_MAX_VCPUS)];
  53         unsigned int dest_vcpus = 0;
  54
  55         if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
  56                 return r;
  57
  58         if (irq->dest_mode == APIC_DEST_PHYSICAL &&
  59             irq->dest_id == 0xff && kvm_lowest_prio_delivery(irq)) {
  60                 pr_info("apic: phys broadcast and lowest prio\n");
  61                 irq->delivery_mode = APIC_DM_FIXED;
  62         }
  63
  64         memset(dest_vcpu_bitmap, 0, sizeof(dest_vcpu_bitmap));
  65
  66         kvm_for_each_vcpu(i, vcpu, kvm) {
  67                 if (!kvm_apic_present(vcpu))
  68                         continue;
  69
  70                 if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
  71                                         irq->dest_id, irq->dest_mode))
  72                         continue;
  73
  74                 if (!kvm_lowest_prio_delivery(irq)) {
  75                         if (r < 0)
  76                                 r = 0;
  77                         r += kvm_apic_set_irq(vcpu, irq, dest_map);
  78                 } else if (kvm_apic_sw_enabled(vcpu->arch.apic)) {
  79                         if (!kvm_vector_hashing_enabled()) {
  80                                 if (!lowest)
  81                                         lowest = vcpu;
  82                                 else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
  83                                         lowest = vcpu;
  84                         } else {
  85                                 __set_bit(i, dest_vcpu_bitmap);
  86                                 dest_vcpus++;
  87                         }
  88                 }
  89         }
  90
  91         if (dest_vcpus != 0) {
  92                 int idx = kvm_vector_to_index(irq->vector, dest_vcpus,
  93                                         dest_vcpu_bitmap, KVM_MAX_VCPUS);
  94
  95                 lowest = kvm_get_vcpu(kvm, idx);
  96         }
  97
  98         if (lowest)
  99                 r = kvm_apic_set_irq(lowest, irq, dest_map);
 100
 101         return r;
 102 }
 103
 104 void kvm_set_msi_irq(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *e,
 105                      struct kvm_lapic_irq *irq)
 106 {
 107         struct msi_msg msg = { .address_lo = e->msi.address_lo,
 108                                .address_hi = e->msi.address_hi,
 109                                .data = e->msi.data };
 110
 111         trace_kvm_msi_set_irq(msg.address_lo | (kvm->arch.x2apic_format ?
 112                               (u64)msg.address_hi << 32 : 0), msg.data);
 113
 114         irq->dest_id = x86_msi_msg_get_destid(&msg, kvm->arch.x2apic_format);
 115         irq->vector = msg.arch_data.vector;
 116         irq->dest_mode = kvm_lapic_irq_dest_mode(msg.arch_addr_lo.dest_mode_logical);
 117         irq->trig_mode = msg.arch_data.is_level;
 118         irq->delivery_mode = msg.arch_data.delivery_mode << 8;
 119         irq->msi_redir_hint = msg.arch_addr_lo.redirect_hint;
 120         irq->level = 1;
 121         irq->shorthand = APIC_DEST_NOSHORT;
 122 }
 123 EXPORT_SYMBOL_GPL(kvm_set_msi_irq);
 124
 125 static inline bool kvm_msi_route_invalid(struct kvm *kvm,
 126                 struct kvm_kernel_irq_routing_entry *e)
 127 {
 128         return kvm->arch.x2apic_format && (e->msi.address_hi & 0xff);
 129 }
 130
 131 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
 132                 struct kvm *kvm, int irq_source_id, int level, bool line_status)
 133 {
 134         struct kvm_lapic_irq irq;
 135
 136         if (kvm_msi_route_invalid(kvm, e))
 137                 return -EINVAL;
 138
 139         if (!level)
 140                 return -1;
 141
 142         kvm_set_msi_irq(kvm, e, &irq);
 143
 144         return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
 145 }
 146
 147 #ifdef CONFIG_KVM_HYPERV
 148 static int kvm_hv_set_sint(struct kvm_kernel_irq_routing_entry *e,
 149                     struct kvm *kvm, int irq_source_id, int level,
 150                     bool line_status)
 151 {
 152         if (!level)
 153                 return -1;
 154
 155         return kvm_hv_synic_set_irq(kvm, e->hv_sint.vcpu, e->hv_sint.sint);
 156 }
 157 #endif
 158
 159 int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
 160                               struct kvm *kvm, int irq_source_id, int level,
 161                               bool line_status)
 162 {
 163         struct kvm_lapic_irq irq;
 164         int r;
 165
 166         switch (e->type) {
 167 #ifdef CONFIG_KVM_HYPERV
 168         case KVM_IRQ_ROUTING_HV_SINT:
 169                 return kvm_hv_set_sint(e, kvm, irq_source_id, level,
 170                                        line_status);
 171 #endif
 172
 173         case KVM_IRQ_ROUTING_MSI:
 174                 if (kvm_msi_route_invalid(kvm, e))
 175                         return -EINVAL;
 176
 177                 kvm_set_msi_irq(kvm, e, &irq);
 178
 179                 if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
 180                         return r;
 181                 break;
 182
 183 #ifdef CONFIG_KVM_XEN
 184         case KVM_IRQ_ROUTING_XEN_EVTCHN:
 185                 if (!level)
 186                         return -1;
 187
 188                 return kvm_xen_set_evtchn_fast(&e->xen_evtchn, kvm);
 189 #endif
 190         default:
 191                 break;
 192         }
 193
 194         return -EWOULDBLOCK;
 195 }
 196
 197 int kvm_request_irq_source_id(struct kvm *kvm)
 198 {
 199         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
 200         int irq_source_id;
 201
 202         mutex_lock(&kvm->irq_lock);
 203         irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
 204
 205         if (irq_source_id >= BITS_PER_LONG) {
 206                 pr_warn("exhausted allocatable IRQ sources!\n");
 207                 irq_source_id = -EFAULT;
 208                 goto unlock;
 209         }
 210
 211         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 212         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 213         set_bit(irq_source_id, bitmap);
 214 unlock:
 215         mutex_unlock(&kvm->irq_lock);
 216
 217         return irq_source_id;
 218 }
 219
 220 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 221 {
 222         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 223         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 224
 225         mutex_lock(&kvm->irq_lock);
 226         if (irq_source_id < 0 ||
 227             irq_source_id >= BITS_PER_LONG) {
 228                 pr_err("IRQ source ID out of range!\n");
 229                 goto unlock;
 230         }
 231         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 232         if (!irqchip_kernel(kvm))
 233                 goto unlock;
 234
 235         kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
 236         kvm_pic_clear_all(kvm->arch.vpic, irq_source_id);
 237 unlock:
 238         mutex_unlock(&kvm->irq_lock);
 239 }
 240
 241 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 242                                     struct kvm_irq_mask_notifier *kimn)
 243 {
 244         mutex_lock(&kvm->irq_lock);
 245         kimn->irq = irq;
 246         hlist_add_head_rcu(&kimn->link, &kvm->arch.mask_notifier_list);
 247         mutex_unlock(&kvm->irq_lock);
 248 }
 249
 250 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 251                                       struct kvm_irq_mask_notifier *kimn)
 252 {
 253         mutex_lock(&kvm->irq_lock);
 254         hlist_del_rcu(&kimn->link);
 255         mutex_unlock(&kvm->irq_lock);
 256         synchronize_srcu(&kvm->irq_srcu);
 257 }
 258
 259 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
 260                              bool mask)
 261 {
 262         struct kvm_irq_mask_notifier *kimn;
 263         int idx, gsi;
 264
 265         idx = srcu_read_lock(&kvm->irq_srcu);
 266         gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
 267         if (gsi != -1)
 268                 hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
 269                         if (kimn->irq == gsi)
 270                                 kimn->func(kimn, mask);
 271         srcu_read_unlock(&kvm->irq_srcu, idx);
 272 }
 273
 274 bool kvm_arch_can_set_irq_routing(struct kvm *kvm)
 275 {
 276         return irqchip_in_kernel(kvm);
 277 }
 278
 279 int kvm_set_routing_entry(struct kvm *kvm,
 280                           struct kvm_kernel_irq_routing_entry *e,
 281                           const struct kvm_irq_routing_entry *ue)
 282 {
 283         /* We can't check irqchip_in_kernel() here as some callers are
 284          * currently initializing the irqchip. Other callers should therefore
 285          * check kvm_arch_can_set_irq_routing() before calling this function.
 286          */
 287         switch (ue->type) {
 288         case KVM_IRQ_ROUTING_IRQCHIP:
 289                 if (irqchip_split(kvm))
 290                         return -EINVAL;
 291                 e->irqchip.pin = ue->u.irqchip.pin;
 292                 switch (ue->u.irqchip.irqchip) {
 293                 case KVM_IRQCHIP_PIC_SLAVE:
 294                         e->irqchip.pin += PIC_NUM_PINS / 2;
 295                         fallthrough;
 296                 case KVM_IRQCHIP_PIC_MASTER:
 297                         if (ue->u.irqchip.pin >= PIC_NUM_PINS / 2)
 298                                 return -EINVAL;
 299                         e->set = kvm_set_pic_irq;
 300                         break;
 301                 case KVM_IRQCHIP_IOAPIC:
 302                         if (ue->u.irqchip.pin >= KVM_IOAPIC_NUM_PINS)
 303                                 return -EINVAL;
 304                         e->set = kvm_set_ioapic_irq;
 305                         break;
 306                 default:
 307                         return -EINVAL;
 308                 }
 309                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 310                 break;
 311         case KVM_IRQ_ROUTING_MSI:
 312                 e->set = kvm_set_msi;
 313                 e->msi.address_lo = ue->u.msi.address_lo;
 314                 e->msi.address_hi = ue->u.msi.address_hi;
 315                 e->msi.data = ue->u.msi.data;
 316
 317                 if (kvm_msi_route_invalid(kvm, e))
 318                         return -EINVAL;
 319                 break;
 320 #ifdef CONFIG_KVM_HYPERV
 321         case KVM_IRQ_ROUTING_HV_SINT:
 322                 e->set = kvm_hv_set_sint;
 323                 e->hv_sint.vcpu = ue->u.hv_sint.vcpu;
 324                 e->hv_sint.sint = ue->u.hv_sint.sint;
 325                 break;
 326 #endif
 327 #ifdef CONFIG_KVM_XEN
 328         case KVM_IRQ_ROUTING_XEN_EVTCHN:
 329                 return kvm_xen_setup_evtchn(kvm, e, ue);
 330 #endif
 331         default:
 332                 return -EINVAL;
 333         }
 334
 335         return 0;
 336 }
 337
 338 bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
 339                              struct kvm_vcpu **dest_vcpu)
 340 {
 341         int r = 0;
 342         unsigned long i;
 343         struct kvm_vcpu *vcpu;
 344
 345         if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
 346                 return true;
 347
 348         kvm_for_each_vcpu(i, vcpu, kvm) {
 349                 if (!kvm_apic_present(vcpu))
 350                         continue;
 351
 352                 if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand,
 353                                         irq->dest_id, irq->dest_mode))
 354                         continue;
 355
 356                 if (++r == 2)
 357                         return false;
 358
 359                 *dest_vcpu = vcpu;
 360         }
 361
 362         return r == 1;
 363 }
 364 EXPORT_SYMBOL_GPL(kvm_intr_is_single_vcpu);
 365
 366 #define IOAPIC_ROUTING_ENTRY(irq) \
 367         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 368           .u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
 369 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 370
 371 #define PIC_ROUTING_ENTRY(irq) \
 372         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 373           .u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
 374 #define ROUTING_ENTRY2(irq) \
 375         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 376
 377 static const struct kvm_irq_routing_entry default_routing[] = {
 378         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 379         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 380         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 381         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 382         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 383         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 384         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 385         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 386         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 387         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 388         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 389         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 390 };
 391
 392 int kvm_setup_default_irq_routing(struct kvm *kvm)
 393 {
 394         return kvm_set_irq_routing(kvm, default_routing,
 395                                    ARRAY_SIZE(default_routing), 0);
 396 }
 397
 398 static const struct kvm_irq_routing_entry empty_routing[] = {};
 399
 400 int kvm_setup_empty_irq_routing(struct kvm *kvm)
 401 {
 402         return kvm_set_irq_routing(kvm, empty_routing, 0, 0);
 403 }
 404
 405 void kvm_arch_post_irq_routing_update(struct kvm *kvm)
 406 {
 407         if (!irqchip_split(kvm))
 408                 return;
 409         kvm_make_scan_ioapic_request(kvm);
 410 }
 411
 412 void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu,
 413                             ulong *ioapic_handled_vectors)
 414 {
 415         struct kvm *kvm = vcpu->kvm;
 416         struct kvm_kernel_irq_routing_entry *entry;
 417         struct kvm_irq_routing_table *table;
 418         u32 i, nr_ioapic_pins;
 419         int idx;
 420
 421         idx = srcu_read_lock(&kvm->irq_srcu);
 422         table = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
 423         nr_ioapic_pins = min_t(u32, table->nr_rt_entries,
 424                                kvm->arch.nr_reserved_ioapic_pins);
 425         for (i = 0; i < nr_ioapic_pins; ++i) {
 426                 hlist_for_each_entry(entry, &table->map[i], link) {
 427                         struct kvm_lapic_irq irq;
 428
 429                         if (entry->type != KVM_IRQ_ROUTING_MSI)
 430                                 continue;
 431
 432                         kvm_set_msi_irq(vcpu->kvm, entry, &irq);
 433
 434                         if (irq.trig_mode &&
 435                             (kvm_apic_match_dest(vcpu, NULL, APIC_DEST_NOSHORT,
 436                                                  irq.dest_id, irq.dest_mode) ||
 437                              kvm_apic_pending_eoi(vcpu, irq.vector)))
 438                                 __set_bit(irq.vector, ioapic_handled_vectors);
 439                 }
 440         }
 441         srcu_read_unlock(&kvm->irq_srcu, idx);
 442 }
 443
 444 void kvm_arch_irq_routing_update(struct kvm *kvm)
 445 {
 446 #ifdef CONFIG_KVM_HYPERV
 447         kvm_hv_irq_routing_update(kvm);
 448 #endif
 449 }