arch/x86/kvm/irq_comm.c

   1 /*
   2  * irq_comm.c: Common API for in kernel interrupt controller
   3  * Copyright (c) 2007, Intel Corporation.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  16  * Place - Suite 330, Boston, MA 02111-1307 USA.
  17  * Authors:
  18  *   Yaozu (Eddie) Dong <Eddie.dong@intel.com>
  19  *
  20  * Copyright 2010 Red Hat, Inc. and/or its affiliates.
  21  */
  22
  23 #include <linux/kvm_host.h>
  24 #include <linux/slab.h>
  25 #include <linux/export.h>
  26 #include <trace/events/kvm.h>
  27
  28 #include <asm/msidef.h>
  29
  30 #include "irq.h"
  31
  32 #include "ioapic.h"
  33
  34 #include "lapic.h"
  35
  36 #include "hyperv.h"
  37 #include "x86.h"
  38
  39 static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
  40                            struct kvm *kvm, int irq_source_id, int level,
  41                            bool line_status)
  42 {
  43         struct kvm_pic *pic = pic_irqchip(kvm);
  44         return kvm_pic_set_irq(pic, e->irqchip.pin, irq_source_id, level);
  45 }
  46
  47 static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
  48                               struct kvm *kvm, int irq_source_id, int level,
  49                               bool line_status)
  50 {
  51         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
  52         return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, irq_source_id, level,
  53                                 line_status);
  54 }
  55
  56 int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
  57                 struct kvm_lapic_irq *irq, struct dest_map *dest_map)
  58 {
  59         int i, r = -1;
  60         struct kvm_vcpu *vcpu, *lowest = NULL;
  61         unsigned long dest_vcpu_bitmap[BITS_TO_LONGS(KVM_MAX_VCPUS)];
  62         unsigned int dest_vcpus = 0;
  63
  64         if (irq->dest_mode == 0 && irq->dest_id == 0xff &&
  65                         kvm_lowest_prio_delivery(irq)) {
  66                 printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
  67                 irq->delivery_mode = APIC_DM_FIXED;
  68         }
  69
  70         if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
  71                 return r;
  72
  73         memset(dest_vcpu_bitmap, 0, sizeof(dest_vcpu_bitmap));
  74
  75         kvm_for_each_vcpu(i, vcpu, kvm) {
  76                 if (!kvm_apic_present(vcpu))
  77                         continue;
  78
  79                 if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
  80                                         irq->dest_id, irq->dest_mode))
  81                         continue;
  82
  83                 if (!kvm_lowest_prio_delivery(irq)) {
  84                         if (r < 0)
  85                                 r = 0;
  86                         r += kvm_apic_set_irq(vcpu, irq, dest_map);
  87                 } else if (kvm_lapic_enabled(vcpu)) {
  88                         if (!kvm_vector_hashing_enabled()) {
  89                                 if (!lowest)
  90                                         lowest = vcpu;
  91                                 else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
  92                                         lowest = vcpu;
  93                         } else {
  94                                 __set_bit(i, dest_vcpu_bitmap);
  95                                 dest_vcpus++;
  96                         }
  97                 }
  98         }
  99
 100         if (dest_vcpus != 0) {
 101                 int idx = kvm_vector_to_index(irq->vector, dest_vcpus,
 102                                         dest_vcpu_bitmap, KVM_MAX_VCPUS);
 103
 104                 lowest = kvm_get_vcpu(kvm, idx);
 105         }
 106
 107         if (lowest)
 108                 r = kvm_apic_set_irq(lowest, irq, dest_map);
 109
 110         return r;
 111 }
 112
 113 void kvm_set_msi_irq(struct kvm_kernel_irq_routing_entry *e,
 114                      struct kvm_lapic_irq *irq)
 115 {
 116         trace_kvm_msi_set_irq(e->msi.address_lo, e->msi.data);
 117
 118         irq->dest_id = (e->msi.address_lo &
 119                         MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
 120         irq->vector = (e->msi.data &
 121                         MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
 122         irq->dest_mode = (1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo;
 123         irq->trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
 124         irq->delivery_mode = e->msi.data & 0x700;
 125         irq->msi_redir_hint = ((e->msi.address_lo
 126                 & MSI_ADDR_REDIRECTION_LOWPRI) > 0);
 127         irq->level = 1;
 128         irq->shorthand = 0;
 129 }
 130 EXPORT_SYMBOL_GPL(kvm_set_msi_irq);
 131
 132 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
 133                 struct kvm *kvm, int irq_source_id, int level, bool line_status)
 134 {
 135         struct kvm_lapic_irq irq;
 136
 137         if (!level)
 138                 return -1;
 139
 140         kvm_set_msi_irq(e, &irq);
 141
 142         return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
 143 }
 144
 145
 146 int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
 147                               struct kvm *kvm, int irq_source_id, int level,
 148                               bool line_status)
 149 {
 150         struct kvm_lapic_irq irq;
 151         int r;
 152
 153         if (unlikely(e->type != KVM_IRQ_ROUTING_MSI))
 154                 return -EWOULDBLOCK;
 155
 156         kvm_set_msi_irq(e, &irq);
 157
 158         if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
 159                 return r;
 160         else
 161                 return -EWOULDBLOCK;
 162 }
 163
 164 int kvm_request_irq_source_id(struct kvm *kvm)
 165 {
 166         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
 167         int irq_source_id;
 168
 169         mutex_lock(&kvm->irq_lock);
 170         irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
 171
 172         if (irq_source_id >= BITS_PER_LONG) {
 173                 printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
 174                 irq_source_id = -EFAULT;
 175                 goto unlock;
 176         }
 177
 178         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 179         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 180         set_bit(irq_source_id, bitmap);
 181 unlock:
 182         mutex_unlock(&kvm->irq_lock);
 183
 184         return irq_source_id;
 185 }
 186
 187 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 188 {
 189         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 190         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 191
 192         mutex_lock(&kvm->irq_lock);
 193         if (irq_source_id < 0 ||
 194             irq_source_id >= BITS_PER_LONG) {
 195                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 196                 goto unlock;
 197         }
 198         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 199         if (!ioapic_in_kernel(kvm))
 200                 goto unlock;
 201
 202         kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
 203         kvm_pic_clear_all(pic_irqchip(kvm), irq_source_id);
 204 unlock:
 205         mutex_unlock(&kvm->irq_lock);
 206 }
 207
 208 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 209                                     struct kvm_irq_mask_notifier *kimn)
 210 {
 211         mutex_lock(&kvm->irq_lock);
 212         kimn->irq = irq;
 213         hlist_add_head_rcu(&kimn->link, &kvm->arch.mask_notifier_list);
 214         mutex_unlock(&kvm->irq_lock);
 215 }
 216
 217 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 218                                       struct kvm_irq_mask_notifier *kimn)
 219 {
 220         mutex_lock(&kvm->irq_lock);
 221         hlist_del_rcu(&kimn->link);
 222         mutex_unlock(&kvm->irq_lock);
 223         synchronize_srcu(&kvm->irq_srcu);
 224 }
 225
 226 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
 227                              bool mask)
 228 {
 229         struct kvm_irq_mask_notifier *kimn;
 230         int idx, gsi;
 231
 232         idx = srcu_read_lock(&kvm->irq_srcu);
 233         gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
 234         if (gsi != -1)
 235                 hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
 236                         if (kimn->irq == gsi)
 237                                 kimn->func(kimn, mask);
 238         srcu_read_unlock(&kvm->irq_srcu, idx);
 239 }
 240
 241 static int kvm_hv_set_sint(struct kvm_kernel_irq_routing_entry *e,
 242                     struct kvm *kvm, int irq_source_id, int level,
 243                     bool line_status)
 244 {
 245         if (!level)
 246                 return -1;
 247
 248         return kvm_hv_synic_set_irq(kvm, e->hv_sint.vcpu, e->hv_sint.sint);
 249 }
 250
 251 int kvm_set_routing_entry(struct kvm_kernel_irq_routing_entry *e,
 252                           const struct kvm_irq_routing_entry *ue)
 253 {
 254         int r = -EINVAL;
 255         int delta;
 256         unsigned max_pin;
 257
 258         switch (ue->type) {
 259         case KVM_IRQ_ROUTING_IRQCHIP:
 260                 delta = 0;
 261                 switch (ue->u.irqchip.irqchip) {
 262                 case KVM_IRQCHIP_PIC_MASTER:
 263                         e->set = kvm_set_pic_irq;
 264                         max_pin = PIC_NUM_PINS;
 265                         break;
 266                 case KVM_IRQCHIP_PIC_SLAVE:
 267                         e->set = kvm_set_pic_irq;
 268                         max_pin = PIC_NUM_PINS;
 269                         delta = 8;
 270                         break;
 271                 case KVM_IRQCHIP_IOAPIC:
 272                         max_pin = KVM_IOAPIC_NUM_PINS;
 273                         e->set = kvm_set_ioapic_irq;
 274                         break;
 275                 default:
 276                         goto out;
 277                 }
 278                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 279                 e->irqchip.pin = ue->u.irqchip.pin + delta;
 280                 if (e->irqchip.pin >= max_pin)
 281                         goto out;
 282                 break;
 283         case KVM_IRQ_ROUTING_MSI:
 284                 e->set = kvm_set_msi;
 285                 e->msi.address_lo = ue->u.msi.address_lo;
 286                 e->msi.address_hi = ue->u.msi.address_hi;
 287                 e->msi.data = ue->u.msi.data;
 288                 break;
 289         case KVM_IRQ_ROUTING_HV_SINT:
 290                 e->set = kvm_hv_set_sint;
 291                 e->hv_sint.vcpu = ue->u.hv_sint.vcpu;
 292                 e->hv_sint.sint = ue->u.hv_sint.sint;
 293                 break;
 294         default:
 295                 goto out;
 296         }
 297
 298         r = 0;
 299 out:
 300         return r;
 301 }
 302
 303 bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
 304                              struct kvm_vcpu **dest_vcpu)
 305 {
 306         int i, r = 0;
 307         struct kvm_vcpu *vcpu;
 308
 309         if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
 310                 return true;
 311
 312         kvm_for_each_vcpu(i, vcpu, kvm) {
 313                 if (!kvm_apic_present(vcpu))
 314                         continue;
 315
 316                 if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand,
 317                                         irq->dest_id, irq->dest_mode))
 318                         continue;
 319
 320                 if (++r == 2)
 321                         return false;
 322
 323                 *dest_vcpu = vcpu;
 324         }
 325
 326         return r == 1;
 327 }
 328 EXPORT_SYMBOL_GPL(kvm_intr_is_single_vcpu);
 329
 330 #define IOAPIC_ROUTING_ENTRY(irq) \
 331         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 332           .u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
 333 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 334
 335 #define PIC_ROUTING_ENTRY(irq) \
 336         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 337           .u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
 338 #define ROUTING_ENTRY2(irq) \
 339         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 340
 341 static const struct kvm_irq_routing_entry default_routing[] = {
 342         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 343         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 344         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 345         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 346         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 347         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 348         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 349         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 350         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 351         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 352         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 353         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 354 };
 355
 356 int kvm_setup_default_irq_routing(struct kvm *kvm)
 357 {
 358         return kvm_set_irq_routing(kvm, default_routing,
 359                                    ARRAY_SIZE(default_routing), 0);
 360 }
 361
 362 static const struct kvm_irq_routing_entry empty_routing[] = {};
 363
 364 int kvm_setup_empty_irq_routing(struct kvm *kvm)
 365 {
 366         return kvm_set_irq_routing(kvm, empty_routing, 0, 0);
 367 }
 368
 369 void kvm_arch_post_irq_routing_update(struct kvm *kvm)
 370 {
 371         if (ioapic_in_kernel(kvm) || !irqchip_in_kernel(kvm))
 372                 return;
 373         kvm_make_scan_ioapic_request(kvm);
 374 }
 375
 376 void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu,
 377                             ulong *ioapic_handled_vectors)
 378 {
 379         struct kvm *kvm = vcpu->kvm;
 380         struct kvm_kernel_irq_routing_entry *entry;
 381         struct kvm_irq_routing_table *table;
 382         u32 i, nr_ioapic_pins;
 383         int idx;
 384
 385         /* kvm->irq_routing must be read after clearing
 386          * KVM_SCAN_IOAPIC. */
 387         smp_mb();
 388         idx = srcu_read_lock(&kvm->irq_srcu);
 389         table = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
 390         nr_ioapic_pins = min_t(u32, table->nr_rt_entries,
 391                                kvm->arch.nr_reserved_ioapic_pins);
 392         for (i = 0; i < nr_ioapic_pins; ++i) {
 393                 hlist_for_each_entry(entry, &table->map[i], link) {
 394                         u32 dest_id, dest_mode;
 395                         bool level;
 396
 397                         if (entry->type != KVM_IRQ_ROUTING_MSI)
 398                                 continue;
 399                         dest_id = (entry->msi.address_lo >> 12) & 0xff;
 400                         dest_mode = (entry->msi.address_lo >> 2) & 0x1;
 401                         level = entry->msi.data & MSI_DATA_TRIGGER_LEVEL;
 402                         if (level && kvm_apic_match_dest(vcpu, NULL, 0,
 403                                                 dest_id, dest_mode)) {
 404                                 u32 vector = entry->msi.data & 0xff;
 405
 406                                 __set_bit(vector,
 407                                           ioapic_handled_vectors);
 408                         }
 409                 }
 410         }
 411         srcu_read_unlock(&kvm->irq_srcu, idx);
 412 }
 413
 414 int kvm_arch_set_irq(struct kvm_kernel_irq_routing_entry *irq, struct kvm *kvm,
 415                      int irq_source_id, int level, bool line_status)
 416 {
 417         switch (irq->type) {
 418         case KVM_IRQ_ROUTING_HV_SINT:
 419                 return kvm_hv_set_sint(irq, kvm, irq_source_id, level,
 420                                        line_status);
 421         default:
 422                 return -EWOULDBLOCK;
 423         }
 424 }
 425
 426 void kvm_arch_irq_routing_update(struct kvm *kvm)
 427 {
 428         kvm_hv_irq_routing_update(kvm);
 429 }