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 <[email protected]>
   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 (irq->dest_mode == 0 && irq->dest_id == 0xff &&
  56                         kvm_lowest_prio_delivery(irq)) {
  57                 printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
  58                 irq->delivery_mode = APIC_DM_FIXED;
  59         }
  60
  61         if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
  62                 return r;
  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 = (1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo;
 118         irq->trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
 119         irq->delivery_mode = e->msi.data & 0x700;
 120         irq->msi_redir_hint = ((e->msi.address_lo
 121                 & MSI_ADDR_REDIRECTION_LOWPRI) > 0);
 122         irq->level = 1;
 123         irq->shorthand = 0;
 124 }
 125 EXPORT_SYMBOL_GPL(kvm_set_msi_irq);
 126
 127 static inline bool kvm_msi_route_invalid(struct kvm *kvm,
 128                 struct kvm_kernel_irq_routing_entry *e)
 129 {
 130         return kvm->arch.x2apic_format && (e->msi.address_hi & 0xff);
 131 }
 132
 133 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
 134                 struct kvm *kvm, int irq_source_id, int level, bool line_status)
 135 {
 136         struct kvm_lapic_irq irq;
 137
 138         if (kvm_msi_route_invalid(kvm, e))
 139                 return -EINVAL;
 140
 141         if (!level)
 142                 return -1;
 143
 144         kvm_set_msi_irq(kvm, e, &irq);
 145
 146         return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
 147 }
 148
 149
 150 static int kvm_hv_set_sint(struct kvm_kernel_irq_routing_entry *e,
 151                     struct kvm *kvm, int irq_source_id, int level,
 152                     bool line_status)
 153 {
 154         if (!level)
 155                 return -1;
 156
 157         return kvm_hv_synic_set_irq(kvm, e->hv_sint.vcpu, e->hv_sint.sint);
 158 }
 159
 160 int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
 161                               struct kvm *kvm, int irq_source_id, int level,
 162                               bool line_status)
 163 {
 164         struct kvm_lapic_irq irq;
 165         int r;
 166
 167         switch (e->type) {
 168         case KVM_IRQ_ROUTING_HV_SINT:
 169                 return kvm_hv_set_sint(e, kvm, irq_source_id, level,
 170                                        line_status);
 171
 172         case KVM_IRQ_ROUTING_MSI:
 173                 if (kvm_msi_route_invalid(kvm, e))
 174                         return -EINVAL;
 175
 176                 kvm_set_msi_irq(kvm, e, &irq);
 177
 178                 if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
 179                         return r;
 180                 break;
 181
 182         default:
 183                 break;
 184         }
 185
 186         return -EWOULDBLOCK;
 187 }
 188
 189 int kvm_request_irq_source_id(struct kvm *kvm)
 190 {
 191         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
 192         int irq_source_id;
 193
 194         mutex_lock(&kvm->irq_lock);
 195         irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
 196
 197         if (irq_source_id >= BITS_PER_LONG) {
 198                 printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
 199                 irq_source_id = -EFAULT;
 200                 goto unlock;
 201         }
 202
 203         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 204         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 205         set_bit(irq_source_id, bitmap);
 206 unlock:
 207         mutex_unlock(&kvm->irq_lock);
 208
 209         return irq_source_id;
 210 }
 211
 212 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 213 {
 214         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 215         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 216
 217         mutex_lock(&kvm->irq_lock);
 218         if (irq_source_id < 0 ||
 219             irq_source_id >= BITS_PER_LONG) {
 220                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 221                 goto unlock;
 222         }
 223         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 224         if (!irqchip_kernel(kvm))
 225                 goto unlock;
 226
 227         kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
 228         kvm_pic_clear_all(kvm->arch.vpic, irq_source_id);
 229 unlock:
 230         mutex_unlock(&kvm->irq_lock);
 231 }
 232
 233 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 234                                     struct kvm_irq_mask_notifier *kimn)
 235 {
 236         mutex_lock(&kvm->irq_lock);
 237         kimn->irq = irq;
 238         hlist_add_head_rcu(&kimn->link, &kvm->arch.mask_notifier_list);
 239         mutex_unlock(&kvm->irq_lock);
 240 }
 241
 242 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 243                                       struct kvm_irq_mask_notifier *kimn)
 244 {
 245         mutex_lock(&kvm->irq_lock);
 246         hlist_del_rcu(&kimn->link);
 247         mutex_unlock(&kvm->irq_lock);
 248         synchronize_srcu(&kvm->irq_srcu);
 249 }
 250
 251 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
 252                              bool mask)
 253 {
 254         struct kvm_irq_mask_notifier *kimn;
 255         int idx, gsi;
 256
 257         idx = srcu_read_lock(&kvm->irq_srcu);
 258         gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
 259         if (gsi != -1)
 260                 hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
 261                         if (kimn->irq == gsi)
 262                                 kimn->func(kimn, mask);
 263         srcu_read_unlock(&kvm->irq_srcu, idx);
 264 }
 265
 266 bool kvm_arch_can_set_irq_routing(struct kvm *kvm)
 267 {
 268         return irqchip_in_kernel(kvm);
 269 }
 270
 271 int kvm_set_routing_entry(struct kvm *kvm,
 272                           struct kvm_kernel_irq_routing_entry *e,
 273                           const struct kvm_irq_routing_entry *ue)
 274 {
 275         /* We can't check irqchip_in_kernel() here as some callers are
 276          * currently inititalizing the irqchip. Other callers should therefore
 277          * check kvm_arch_can_set_irq_routing() before calling this function.
 278          */
 279         switch (ue->type) {
 280         case KVM_IRQ_ROUTING_IRQCHIP:
 281                 if (irqchip_split(kvm))
 282                         return -EINVAL;
 283                 e->irqchip.pin = ue->u.irqchip.pin;
 284                 switch (ue->u.irqchip.irqchip) {
 285                 case KVM_IRQCHIP_PIC_SLAVE:
 286                         e->irqchip.pin += PIC_NUM_PINS / 2;
 287                         /* fall through */
 288                 case KVM_IRQCHIP_PIC_MASTER:
 289                         if (ue->u.irqchip.pin >= PIC_NUM_PINS / 2)
 290                                 return -EINVAL;
 291                         e->set = kvm_set_pic_irq;
 292                         break;
 293                 case KVM_IRQCHIP_IOAPIC:
 294                         if (ue->u.irqchip.pin >= KVM_IOAPIC_NUM_PINS)
 295                                 return -EINVAL;
 296                         e->set = kvm_set_ioapic_irq;
 297                         break;
 298                 default:
 299                         return -EINVAL;
 300                 }
 301                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 302                 break;
 303         case KVM_IRQ_ROUTING_MSI:
 304                 e->set = kvm_set_msi;
 305                 e->msi.address_lo = ue->u.msi.address_lo;
 306                 e->msi.address_hi = ue->u.msi.address_hi;
 307                 e->msi.data = ue->u.msi.data;
 308
 309                 if (kvm_msi_route_invalid(kvm, e))
 310                         return -EINVAL;
 311                 break;
 312         case KVM_IRQ_ROUTING_HV_SINT:
 313                 e->set = kvm_hv_set_sint;
 314                 e->hv_sint.vcpu = ue->u.hv_sint.vcpu;
 315                 e->hv_sint.sint = ue->u.hv_sint.sint;
 316                 break;
 317         default:
 318                 return -EINVAL;
 319         }
 320
 321         return 0;
 322 }
 323
 324 bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
 325                              struct kvm_vcpu **dest_vcpu)
 326 {
 327         int i, r = 0;
 328         struct kvm_vcpu *vcpu;
 329
 330         if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
 331                 return true;
 332
 333         kvm_for_each_vcpu(i, vcpu, kvm) {
 334                 if (!kvm_apic_present(vcpu))
 335                         continue;
 336
 337                 if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand,
 338                                         irq->dest_id, irq->dest_mode))
 339                         continue;
 340
 341                 if (++r == 2)
 342                         return false;
 343
 344                 *dest_vcpu = vcpu;
 345         }
 346
 347         return r == 1;
 348 }
 349 EXPORT_SYMBOL_GPL(kvm_intr_is_single_vcpu);
 350
 351 #define IOAPIC_ROUTING_ENTRY(irq) \
 352         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 353           .u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
 354 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 355
 356 #define PIC_ROUTING_ENTRY(irq) \
 357         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 358           .u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
 359 #define ROUTING_ENTRY2(irq) \
 360         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 361
 362 static const struct kvm_irq_routing_entry default_routing[] = {
 363         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 364         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 365         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 366         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 367         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 368         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 369         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 370         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 371         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 372         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 373         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 374         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 375 };
 376
 377 int kvm_setup_default_irq_routing(struct kvm *kvm)
 378 {
 379         return kvm_set_irq_routing(kvm, default_routing,
 380                                    ARRAY_SIZE(default_routing), 0);
 381 }
 382
 383 static const struct kvm_irq_routing_entry empty_routing[] = {};
 384
 385 int kvm_setup_empty_irq_routing(struct kvm *kvm)
 386 {
 387         return kvm_set_irq_routing(kvm, empty_routing, 0, 0);
 388 }
 389
 390 void kvm_arch_post_irq_routing_update(struct kvm *kvm)
 391 {
 392         if (!irqchip_split(kvm))
 393                 return;
 394         kvm_make_scan_ioapic_request(kvm);
 395 }
 396
 397 void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu,
 398                             ulong *ioapic_handled_vectors)
 399 {
 400         struct kvm *kvm = vcpu->kvm;
 401         struct kvm_kernel_irq_routing_entry *entry;
 402         struct kvm_irq_routing_table *table;
 403         u32 i, nr_ioapic_pins;
 404         int idx;
 405
 406         idx = srcu_read_lock(&kvm->irq_srcu);
 407         table = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
 408         nr_ioapic_pins = min_t(u32, table->nr_rt_entries,
 409                                kvm->arch.nr_reserved_ioapic_pins);
 410         for (i = 0; i < nr_ioapic_pins; ++i) {
 411                 hlist_for_each_entry(entry, &table->map[i], link) {
 412                         struct kvm_lapic_irq irq;
 413
 414                         if (entry->type != KVM_IRQ_ROUTING_MSI)
 415                                 continue;
 416
 417                         kvm_set_msi_irq(vcpu->kvm, entry, &irq);
 418
 419                         if (irq.level && kvm_apic_match_dest(vcpu, NULL, 0,
 420                                                 irq.dest_id, irq.dest_mode))
 421                                 __set_bit(irq.vector, ioapic_handled_vectors);
 422                 }
 423         }
 424         srcu_read_unlock(&kvm->irq_srcu, idx);
 425 }
 426
 427 void kvm_arch_irq_routing_update(struct kvm *kvm)
 428 {
 429         kvm_hv_irq_routing_update(kvm);
 430 }