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 <asm/msidef.h>
  20
  21 #include "irq.h"
  22
  23 #include "ioapic.h"
  24
  25 #include "lapic.h"
  26
  27 #include "hyperv.h"
  28 #include "x86.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 i, r = -1;
  51         struct kvm_vcpu *vcpu, *lowest = NULL;
  52         unsigned long 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                 printk(KERN_INFO "kvm: 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         trace_kvm_msi_set_irq(e->msi.address_lo | (kvm->arch.x2apic_format ?
 108                                              (u64)e->msi.address_hi << 32 : 0),
 109                               e->msi.data);
 110
 111         irq->dest_id = (e->msi.address_lo &
 112                         MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
 113         if (kvm->arch.x2apic_format)
 114                 irq->dest_id |= MSI_ADDR_EXT_DEST_ID(e->msi.address_hi);
 115         irq->vector = (e->msi.data &
 116                         MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
 117         irq->dest_mode = kvm_lapic_irq_dest_mode(
 118             !!((1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo));
 119         irq->trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
 120         irq->delivery_mode = e->msi.data & 0x700;
 121         irq->msi_redir_hint = ((e->msi.address_lo
 122                 & MSI_ADDR_REDIRECTION_LOWPRI) > 0);
 123         irq->level = 1;
 124         irq->shorthand = APIC_DEST_NOSHORT;
 125 }
 126 EXPORT_SYMBOL_GPL(kvm_set_msi_irq);
 127
 128 static inline bool kvm_msi_route_invalid(struct kvm *kvm,
 129                 struct kvm_kernel_irq_routing_entry *e)
 130 {
 131         return kvm->arch.x2apic_format && (e->msi.address_hi & 0xff);
 132 }
 133
 134 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
 135                 struct kvm *kvm, int irq_source_id, int level, bool line_status)
 136 {
 137         struct kvm_lapic_irq irq;
 138
 139         if (kvm_msi_route_invalid(kvm, e))
 140                 return -EINVAL;
 141
 142         if (!level)
 143                 return -1;
 144
 145         kvm_set_msi_irq(kvm, e, &irq);
 146
 147         return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
 148 }
 149
 150
 151 static int kvm_hv_set_sint(struct kvm_kernel_irq_routing_entry *e,
 152                     struct kvm *kvm, int irq_source_id, int level,
 153                     bool line_status)
 154 {
 155         if (!level)
 156                 return -1;
 157
 158         return kvm_hv_synic_set_irq(kvm, e->hv_sint.vcpu, e->hv_sint.sint);
 159 }
 160
 161 int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
 162                               struct kvm *kvm, int irq_source_id, int level,
 163                               bool line_status)
 164 {
 165         struct kvm_lapic_irq irq;
 166         int r;
 167
 168         switch (e->type) {
 169         case KVM_IRQ_ROUTING_HV_SINT:
 170                 return kvm_hv_set_sint(e, kvm, irq_source_id, level,
 171                                        line_status);
 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         default:
 184                 break;
 185         }
 186
 187         return -EWOULDBLOCK;
 188 }
 189
 190 int kvm_request_irq_source_id(struct kvm *kvm)
 191 {
 192         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
 193         int irq_source_id;
 194
 195         mutex_lock(&kvm->irq_lock);
 196         irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
 197
 198         if (irq_source_id >= BITS_PER_LONG) {
 199                 printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
 200                 irq_source_id = -EFAULT;
 201                 goto unlock;
 202         }
 203
 204         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 205         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 206         set_bit(irq_source_id, bitmap);
 207 unlock:
 208         mutex_unlock(&kvm->irq_lock);
 209
 210         return irq_source_id;
 211 }
 212
 213 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 214 {
 215         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 216         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 217
 218         mutex_lock(&kvm->irq_lock);
 219         if (irq_source_id < 0 ||
 220             irq_source_id >= BITS_PER_LONG) {
 221                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 222                 goto unlock;
 223         }
 224         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 225         if (!irqchip_kernel(kvm))
 226                 goto unlock;
 227
 228         kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
 229         kvm_pic_clear_all(kvm->arch.vpic, irq_source_id);
 230 unlock:
 231         mutex_unlock(&kvm->irq_lock);
 232 }
 233
 234 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 235                                     struct kvm_irq_mask_notifier *kimn)
 236 {
 237         mutex_lock(&kvm->irq_lock);
 238         kimn->irq = irq;
 239         hlist_add_head_rcu(&kimn->link, &kvm->arch.mask_notifier_list);
 240         mutex_unlock(&kvm->irq_lock);
 241 }
 242
 243 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 244                                       struct kvm_irq_mask_notifier *kimn)
 245 {
 246         mutex_lock(&kvm->irq_lock);
 247         hlist_del_rcu(&kimn->link);
 248         mutex_unlock(&kvm->irq_lock);
 249         synchronize_srcu(&kvm->irq_srcu);
 250 }
 251
 252 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
 253                              bool mask)
 254 {
 255         struct kvm_irq_mask_notifier *kimn;
 256         int idx, gsi;
 257
 258         idx = srcu_read_lock(&kvm->irq_srcu);
 259         gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
 260         if (gsi != -1)
 261                 hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
 262                         if (kimn->irq == gsi)
 263                                 kimn->func(kimn, mask);
 264         srcu_read_unlock(&kvm->irq_srcu, idx);
 265 }
 266
 267 bool kvm_arch_can_set_irq_routing(struct kvm *kvm)
 268 {
 269         return irqchip_in_kernel(kvm);
 270 }
 271
 272 int kvm_set_routing_entry(struct kvm *kvm,
 273                           struct kvm_kernel_irq_routing_entry *e,
 274                           const struct kvm_irq_routing_entry *ue)
 275 {
 276         /* We can't check irqchip_in_kernel() here as some callers are
 277          * currently inititalizing the irqchip. Other callers should therefore
 278          * check kvm_arch_can_set_irq_routing() before calling this function.
 279          */
 280         switch (ue->type) {
 281         case KVM_IRQ_ROUTING_IRQCHIP:
 282                 if (irqchip_split(kvm))
 283                         return -EINVAL;
 284                 e->irqchip.pin = ue->u.irqchip.pin;
 285                 switch (ue->u.irqchip.irqchip) {
 286                 case KVM_IRQCHIP_PIC_SLAVE:
 287                         e->irqchip.pin += PIC_NUM_PINS / 2;
 288                         fallthrough;
 289                 case KVM_IRQCHIP_PIC_MASTER:
 290                         if (ue->u.irqchip.pin >= PIC_NUM_PINS / 2)
 291                                 return -EINVAL;
 292                         e->set = kvm_set_pic_irq;
 293                         break;
 294                 case KVM_IRQCHIP_IOAPIC:
 295                         if (ue->u.irqchip.pin >= KVM_IOAPIC_NUM_PINS)
 296                                 return -EINVAL;
 297                         e->set = kvm_set_ioapic_irq;
 298                         break;
 299                 default:
 300                         return -EINVAL;
 301                 }
 302                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 303                 break;
 304         case KVM_IRQ_ROUTING_MSI:
 305                 e->set = kvm_set_msi;
 306                 e->msi.address_lo = ue->u.msi.address_lo;
 307                 e->msi.address_hi = ue->u.msi.address_hi;
 308                 e->msi.data = ue->u.msi.data;
 309
 310                 if (kvm_msi_route_invalid(kvm, e))
 311                         return -EINVAL;
 312                 break;
 313         case KVM_IRQ_ROUTING_HV_SINT:
 314                 e->set = kvm_hv_set_sint;
 315                 e->hv_sint.vcpu = ue->u.hv_sint.vcpu;
 316                 e->hv_sint.sint = ue->u.hv_sint.sint;
 317                 break;
 318         default:
 319                 return -EINVAL;
 320         }
 321
 322         return 0;
 323 }
 324
 325 bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
 326                              struct kvm_vcpu **dest_vcpu)
 327 {
 328         int i, r = 0;
 329         struct kvm_vcpu *vcpu;
 330
 331         if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
 332                 return true;
 333
 334         kvm_for_each_vcpu(i, vcpu, kvm) {
 335                 if (!kvm_apic_present(vcpu))
 336                         continue;
 337
 338                 if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand,
 339                                         irq->dest_id, irq->dest_mode))
 340                         continue;
 341
 342                 if (++r == 2)
 343                         return false;
 344
 345                 *dest_vcpu = vcpu;
 346         }
 347
 348         return r == 1;
 349 }
 350 EXPORT_SYMBOL_GPL(kvm_intr_is_single_vcpu);
 351
 352 #define IOAPIC_ROUTING_ENTRY(irq) \
 353         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 354           .u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
 355 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 356
 357 #define PIC_ROUTING_ENTRY(irq) \
 358         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 359           .u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
 360 #define ROUTING_ENTRY2(irq) \
 361         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 362
 363 static const struct kvm_irq_routing_entry default_routing[] = {
 364         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 365         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 366         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 367         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 368         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 369         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 370         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 371         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 372         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 373         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 374         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 375         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 376 };
 377
 378 int kvm_setup_default_irq_routing(struct kvm *kvm)
 379 {
 380         return kvm_set_irq_routing(kvm, default_routing,
 381                                    ARRAY_SIZE(default_routing), 0);
 382 }
 383
 384 static const struct kvm_irq_routing_entry empty_routing[] = {};
 385
 386 int kvm_setup_empty_irq_routing(struct kvm *kvm)
 387 {
 388         return kvm_set_irq_routing(kvm, empty_routing, 0, 0);
 389 }
 390
 391 void kvm_arch_post_irq_routing_update(struct kvm *kvm)
 392 {
 393         if (!irqchip_split(kvm))
 394                 return;
 395         kvm_make_scan_ioapic_request(kvm);
 396 }
 397
 398 void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu,
 399                             ulong *ioapic_handled_vectors)
 400 {
 401         struct kvm *kvm = vcpu->kvm;
 402         struct kvm_kernel_irq_routing_entry *entry;
 403         struct kvm_irq_routing_table *table;
 404         u32 i, nr_ioapic_pins;
 405         int idx;
 406
 407         idx = srcu_read_lock(&kvm->irq_srcu);
 408         table = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
 409         nr_ioapic_pins = min_t(u32, table->nr_rt_entries,
 410                                kvm->arch.nr_reserved_ioapic_pins);
 411         for (i = 0; i < nr_ioapic_pins; ++i) {
 412                 hlist_for_each_entry(entry, &table->map[i], link) {
 413                         struct kvm_lapic_irq irq;
 414
 415                         if (entry->type != KVM_IRQ_ROUTING_MSI)
 416                                 continue;
 417
 418                         kvm_set_msi_irq(vcpu->kvm, entry, &irq);
 419
 420                         if (irq.trig_mode &&
 421                             kvm_apic_match_dest(vcpu, NULL, APIC_DEST_NOSHORT,
 422                                                 irq.dest_id, irq.dest_mode))
 423                                 __set_bit(irq.vector, ioapic_handled_vectors);
 424                 }
 425         }
 426         srcu_read_unlock(&kvm->irq_srcu, idx);
 427 }
 428
 429 void kvm_arch_irq_routing_update(struct kvm *kvm)
 430 {
 431         kvm_hv_irq_routing_update(kvm);
 432 }