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