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
 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
 158 int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
 159                               struct kvm *kvm, int irq_source_id, int level,
 160                               bool line_status)
 161 {
 162         struct kvm_lapic_irq irq;
 163         int r;
 164
 165         switch (e->type) {
 166         case KVM_IRQ_ROUTING_HV_SINT:
 167                 return kvm_hv_set_sint(e, kvm, irq_source_id, level,
 168                                        line_status);
 169
 170         case KVM_IRQ_ROUTING_MSI:
 171                 if (kvm_msi_route_invalid(kvm, e))
 172                         return -EINVAL;
 173
 174                 kvm_set_msi_irq(kvm, e, &irq);
 175
 176                 if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
 177                         return r;
 178                 break;
 179
 180 #ifdef CONFIG_KVM_XEN
 181         case KVM_IRQ_ROUTING_XEN_EVTCHN:
 182                 if (!level)
 183                         return -1;
 184
 185                 return kvm_xen_set_evtchn_fast(&e->xen_evtchn, kvm);
 186 #endif
 187         default:
 188                 break;
 189         }
 190
 191         return -EWOULDBLOCK;
 192 }
 193
 194 int kvm_request_irq_source_id(struct kvm *kvm)
 195 {
 196         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
 197         int irq_source_id;
 198
 199         mutex_lock(&kvm->irq_lock);
 200         irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
 201
 202         if (irq_source_id >= BITS_PER_LONG) {
 203                 pr_warn("exhausted allocatable IRQ sources!\n");
 204                 irq_source_id = -EFAULT;
 205                 goto unlock;
 206         }
 207
 208         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 209         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 210         set_bit(irq_source_id, bitmap);
 211 unlock:
 212         mutex_unlock(&kvm->irq_lock);
 213
 214         return irq_source_id;
 215 }
 216
 217 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 218 {
 219         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 220         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 221
 222         mutex_lock(&kvm->irq_lock);
 223         if (irq_source_id < 0 ||
 224             irq_source_id >= BITS_PER_LONG) {
 225                 pr_err("IRQ source ID out of range!\n");
 226                 goto unlock;
 227         }
 228         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 229         if (!irqchip_kernel(kvm))
 230                 goto unlock;
 231
 232         kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
 233         kvm_pic_clear_all(kvm->arch.vpic, irq_source_id);
 234 unlock:
 235         mutex_unlock(&kvm->irq_lock);
 236 }
 237
 238 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 239                                     struct kvm_irq_mask_notifier *kimn)
 240 {
 241         mutex_lock(&kvm->irq_lock);
 242         kimn->irq = irq;
 243         hlist_add_head_rcu(&kimn->link, &kvm->arch.mask_notifier_list);
 244         mutex_unlock(&kvm->irq_lock);
 245 }
 246
 247 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 248                                       struct kvm_irq_mask_notifier *kimn)
 249 {
 250         mutex_lock(&kvm->irq_lock);
 251         hlist_del_rcu(&kimn->link);
 252         mutex_unlock(&kvm->irq_lock);
 253         synchronize_srcu(&kvm->irq_srcu);
 254 }
 255
 256 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
 257                              bool mask)
 258 {
 259         struct kvm_irq_mask_notifier *kimn;
 260         int idx, gsi;
 261
 262         idx = srcu_read_lock(&kvm->irq_srcu);
 263         gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
 264         if (gsi != -1)
 265                 hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
 266                         if (kimn->irq == gsi)
 267                                 kimn->func(kimn, mask);
 268         srcu_read_unlock(&kvm->irq_srcu, idx);
 269 }
 270
 271 bool kvm_arch_can_set_irq_routing(struct kvm *kvm)
 272 {
 273         return irqchip_in_kernel(kvm);
 274 }
 275
 276 int kvm_set_routing_entry(struct kvm *kvm,
 277                           struct kvm_kernel_irq_routing_entry *e,
 278                           const struct kvm_irq_routing_entry *ue)
 279 {
 280         /* We can't check irqchip_in_kernel() here as some callers are
 281          * currently initializing the irqchip. Other callers should therefore
 282          * check kvm_arch_can_set_irq_routing() before calling this function.
 283          */
 284         switch (ue->type) {
 285         case KVM_IRQ_ROUTING_IRQCHIP:
 286                 if (irqchip_split(kvm))
 287                         return -EINVAL;
 288                 e->irqchip.pin = ue->u.irqchip.pin;
 289                 switch (ue->u.irqchip.irqchip) {
 290                 case KVM_IRQCHIP_PIC_SLAVE:
 291                         e->irqchip.pin += PIC_NUM_PINS / 2;
 292                         fallthrough;
 293                 case KVM_IRQCHIP_PIC_MASTER:
 294                         if (ue->u.irqchip.pin >= PIC_NUM_PINS / 2)
 295                                 return -EINVAL;
 296                         e->set = kvm_set_pic_irq;
 297                         break;
 298                 case KVM_IRQCHIP_IOAPIC:
 299                         if (ue->u.irqchip.pin >= KVM_IOAPIC_NUM_PINS)
 300                                 return -EINVAL;
 301                         e->set = kvm_set_ioapic_irq;
 302                         break;
 303                 default:
 304                         return -EINVAL;
 305                 }
 306                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 307                 break;
 308         case KVM_IRQ_ROUTING_MSI:
 309                 e->set = kvm_set_msi;
 310                 e->msi.address_lo = ue->u.msi.address_lo;
 311                 e->msi.address_hi = ue->u.msi.address_hi;
 312                 e->msi.data = ue->u.msi.data;
 313
 314                 if (kvm_msi_route_invalid(kvm, e))
 315                         return -EINVAL;
 316                 break;
 317         case KVM_IRQ_ROUTING_HV_SINT:
 318                 e->set = kvm_hv_set_sint;
 319                 e->hv_sint.vcpu = ue->u.hv_sint.vcpu;
 320                 e->hv_sint.sint = ue->u.hv_sint.sint;
 321                 break;
 322 #ifdef CONFIG_KVM_XEN
 323         case KVM_IRQ_ROUTING_XEN_EVTCHN:
 324                 return kvm_xen_setup_evtchn(kvm, e, ue);
 325 #endif
 326         default:
 327                 return -EINVAL;
 328         }
 329
 330         return 0;
 331 }
 332
 333 bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
 334                              struct kvm_vcpu **dest_vcpu)
 335 {
 336         int r = 0;
 337         unsigned long i;
 338         struct kvm_vcpu *vcpu;
 339
 340         if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
 341                 return true;
 342
 343         kvm_for_each_vcpu(i, vcpu, kvm) {
 344                 if (!kvm_apic_present(vcpu))
 345                         continue;
 346
 347                 if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand,
 348                                         irq->dest_id, irq->dest_mode))
 349                         continue;
 350
 351                 if (++r == 2)
 352                         return false;
 353
 354                 *dest_vcpu = vcpu;
 355         }
 356
 357         return r == 1;
 358 }
 359 EXPORT_SYMBOL_GPL(kvm_intr_is_single_vcpu);
 360
 361 #define IOAPIC_ROUTING_ENTRY(irq) \
 362         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 363           .u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
 364 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 365
 366 #define PIC_ROUTING_ENTRY(irq) \
 367         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 368           .u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
 369 #define ROUTING_ENTRY2(irq) \
 370         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 371
 372 static const struct kvm_irq_routing_entry default_routing[] = {
 373         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 374         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 375         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 376         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 377         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 378         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 379         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 380         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 381         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 382         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 383         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 384         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 385 };
 386
 387 int kvm_setup_default_irq_routing(struct kvm *kvm)
 388 {
 389         return kvm_set_irq_routing(kvm, default_routing,
 390                                    ARRAY_SIZE(default_routing), 0);
 391 }
 392
 393 static const struct kvm_irq_routing_entry empty_routing[] = {};
 394
 395 int kvm_setup_empty_irq_routing(struct kvm *kvm)
 396 {
 397         return kvm_set_irq_routing(kvm, empty_routing, 0, 0);
 398 }
 399
 400 void kvm_arch_post_irq_routing_update(struct kvm *kvm)
 401 {
 402         if (!irqchip_split(kvm))
 403                 return;
 404         kvm_make_scan_ioapic_request(kvm);
 405 }
 406
 407 void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu,
 408                             ulong *ioapic_handled_vectors)
 409 {
 410         struct kvm *kvm = vcpu->kvm;
 411         struct kvm_kernel_irq_routing_entry *entry;
 412         struct kvm_irq_routing_table *table;
 413         u32 i, nr_ioapic_pins;
 414         int idx;
 415
 416         idx = srcu_read_lock(&kvm->irq_srcu);
 417         table = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
 418         nr_ioapic_pins = min_t(u32, table->nr_rt_entries,
 419                                kvm->arch.nr_reserved_ioapic_pins);
 420         for (i = 0; i < nr_ioapic_pins; ++i) {
 421                 hlist_for_each_entry(entry, &table->map[i], link) {
 422                         struct kvm_lapic_irq irq;
 423
 424                         if (entry->type != KVM_IRQ_ROUTING_MSI)
 425                                 continue;
 426
 427                         kvm_set_msi_irq(vcpu->kvm, entry, &irq);
 428
 429                         if (irq.trig_mode &&
 430                             (kvm_apic_match_dest(vcpu, NULL, APIC_DEST_NOSHORT,
 431                                                  irq.dest_id, irq.dest_mode) ||
 432                              kvm_apic_pending_eoi(vcpu, irq.vector)))
 433                                 __set_bit(irq.vector, ioapic_handled_vectors);
 434                 }
 435         }
 436         srcu_read_unlock(&kvm->irq_srcu, idx);
 437 }
 438
 439 void kvm_arch_irq_routing_update(struct kvm *kvm)
 440 {
 441         kvm_hv_irq_routing_update(kvm);
 442 }