virt/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 <trace/events/kvm.h>
  26
  27 #include <asm/msidef.h>
  28 #ifdef CONFIG_IA64
  29 #include <asm/iosapic.h>
  30 #endif
  31
  32 #include "irq.h"
  33
  34 #include "ioapic.h"
  35
  36 static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
  37                            struct kvm *kvm, int irq_source_id, int level)
  38 {
  39 #ifdef CONFIG_X86
  40         struct kvm_pic *pic = pic_irqchip(kvm);
  41         return kvm_pic_set_irq(pic, e->irqchip.pin, irq_source_id, level);
  42 #else
  43         return -1;
  44 #endif
  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 {
  50         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
  51         return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, irq_source_id, level);
  52 }
  53
  54 inline static bool kvm_is_dm_lowest_prio(struct kvm_lapic_irq *irq)
  55 {
  56 #ifdef CONFIG_IA64
  57         return irq->delivery_mode ==
  58                 (IOSAPIC_LOWEST_PRIORITY << IOSAPIC_DELIVERY_SHIFT);
  59 #else
  60         return irq->delivery_mode == APIC_DM_LOWEST;
  61 #endif
  62 }
  63
  64 int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
  65                 struct kvm_lapic_irq *irq)
  66 {
  67         int i, r = -1;
  68         struct kvm_vcpu *vcpu, *lowest = NULL;
  69
  70         if (irq->dest_mode == 0 && irq->dest_id == 0xff &&
  71                         kvm_is_dm_lowest_prio(irq)) {
  72                 printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
  73                 irq->delivery_mode = APIC_DM_FIXED;
  74         }
  75
  76         if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r))
  77                 return r;
  78
  79         kvm_for_each_vcpu(i, vcpu, kvm) {
  80                 if (!kvm_apic_present(vcpu))
  81                         continue;
  82
  83                 if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
  84                                         irq->dest_id, irq->dest_mode))
  85                         continue;
  86
  87                 if (!kvm_is_dm_lowest_prio(irq)) {
  88                         if (r < 0)
  89                                 r = 0;
  90                         r += kvm_apic_set_irq(vcpu, irq);
  91                 } else if (kvm_lapic_enabled(vcpu)) {
  92                         if (!lowest)
  93                                 lowest = vcpu;
  94                         else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
  95                                 lowest = vcpu;
  96                 }
  97         }
  98
  99         if (lowest)
 100                 r = kvm_apic_set_irq(lowest, irq);
 101
 102         return r;
 103 }
 104
 105 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
 106                 struct kvm *kvm, int irq_source_id, int level)
 107 {
 108         struct kvm_lapic_irq irq;
 109
 110         if (!level)
 111                 return -1;
 112
 113         trace_kvm_msi_set_irq(e->msi.address_lo, e->msi.data);
 114
 115         irq.dest_id = (e->msi.address_lo &
 116                         MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
 117         irq.vector = (e->msi.data &
 118                         MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
 119         irq.dest_mode = (1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo;
 120         irq.trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
 121         irq.delivery_mode = e->msi.data & 0x700;
 122         irq.level = 1;
 123         irq.shorthand = 0;
 124
 125         /* TODO Deal with RH bit of MSI message address */
 126         return kvm_irq_delivery_to_apic(kvm, NULL, &irq);
 127 }
 128
 129 int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi)
 130 {
 131         struct kvm_kernel_irq_routing_entry route;
 132
 133         if (!irqchip_in_kernel(kvm) || msi->flags != 0)
 134                 return -EINVAL;
 135
 136         route.msi.address_lo = msi->address_lo;
 137         route.msi.address_hi = msi->address_hi;
 138         route.msi.data = msi->data;
 139
 140         return kvm_set_msi(&route, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, 1);
 141 }
 142
 143 /*
 144  * Return value:
 145  *  < 0   Interrupt was ignored (masked or not delivered for other reasons)
 146  *  = 0   Interrupt was coalesced (previous irq is still pending)
 147  *  > 0   Number of CPUs interrupt was delivered to
 148  */
 149 int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level)
 150 {
 151         struct kvm_kernel_irq_routing_entry *e, irq_set[KVM_NR_IRQCHIPS];
 152         int ret = -1, i = 0;
 153         struct kvm_irq_routing_table *irq_rt;
 154         struct hlist_node *n;
 155
 156         trace_kvm_set_irq(irq, level, irq_source_id);
 157
 158         /* Not possible to detect if the guest uses the PIC or the
 159          * IOAPIC.  So set the bit in both. The guest will ignore
 160          * writes to the unused one.
 161          */
 162         rcu_read_lock();
 163         irq_rt = rcu_dereference(kvm->irq_routing);
 164         if (irq < irq_rt->nr_rt_entries)
 165                 hlist_for_each_entry(e, n, &irq_rt->map[irq], link)
 166                         irq_set[i++] = *e;
 167         rcu_read_unlock();
 168
 169         while(i--) {
 170                 int r;
 171                 r = irq_set[i].set(&irq_set[i], kvm, irq_source_id, level);
 172                 if (r < 0)
 173                         continue;
 174
 175                 ret = r + ((ret < 0) ? 0 : ret);
 176         }
 177
 178         return ret;
 179 }
 180
 181 void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
 182 {
 183         struct kvm_irq_ack_notifier *kian;
 184         struct hlist_node *n;
 185         int gsi;
 186
 187         trace_kvm_ack_irq(irqchip, pin);
 188
 189         rcu_read_lock();
 190         gsi = rcu_dereference(kvm->irq_routing)->chip[irqchip][pin];
 191         if (gsi != -1)
 192                 hlist_for_each_entry_rcu(kian, n, &kvm->irq_ack_notifier_list,
 193                                          link)
 194                         if (kian->gsi == gsi)
 195                                 kian->irq_acked(kian);
 196         rcu_read_unlock();
 197 }
 198
 199 void kvm_register_irq_ack_notifier(struct kvm *kvm,
 200                                    struct kvm_irq_ack_notifier *kian)
 201 {
 202         mutex_lock(&kvm->irq_lock);
 203         hlist_add_head_rcu(&kian->link, &kvm->irq_ack_notifier_list);
 204         mutex_unlock(&kvm->irq_lock);
 205 }
 206
 207 void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
 208                                     struct kvm_irq_ack_notifier *kian)
 209 {
 210         mutex_lock(&kvm->irq_lock);
 211         hlist_del_init_rcu(&kian->link);
 212         mutex_unlock(&kvm->irq_lock);
 213         synchronize_rcu();
 214 }
 215
 216 int kvm_request_irq_source_id(struct kvm *kvm)
 217 {
 218         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
 219         int irq_source_id;
 220
 221         mutex_lock(&kvm->irq_lock);
 222         irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
 223
 224         if (irq_source_id >= BITS_PER_LONG) {
 225                 printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
 226                 irq_source_id = -EFAULT;
 227                 goto unlock;
 228         }
 229
 230         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 231 #ifdef CONFIG_X86
 232         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 233 #endif
 234         set_bit(irq_source_id, bitmap);
 235 unlock:
 236         mutex_unlock(&kvm->irq_lock);
 237
 238         return irq_source_id;
 239 }
 240
 241 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 242 {
 243         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 244 #ifdef CONFIG_X86
 245         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 246 #endif
 247
 248         mutex_lock(&kvm->irq_lock);
 249         if (irq_source_id < 0 ||
 250             irq_source_id >= BITS_PER_LONG) {
 251                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 252                 goto unlock;
 253         }
 254         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 255         if (!irqchip_in_kernel(kvm))
 256                 goto unlock;
 257
 258         kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
 259 #ifdef CONFIG_X86
 260         kvm_pic_clear_all(pic_irqchip(kvm), irq_source_id);
 261 #endif
 262 unlock:
 263         mutex_unlock(&kvm->irq_lock);
 264 }
 265
 266 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 267                                     struct kvm_irq_mask_notifier *kimn)
 268 {
 269         mutex_lock(&kvm->irq_lock);
 270         kimn->irq = irq;
 271         hlist_add_head_rcu(&kimn->link, &kvm->mask_notifier_list);
 272         mutex_unlock(&kvm->irq_lock);
 273 }
 274
 275 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 276                                       struct kvm_irq_mask_notifier *kimn)
 277 {
 278         mutex_lock(&kvm->irq_lock);
 279         hlist_del_rcu(&kimn->link);
 280         mutex_unlock(&kvm->irq_lock);
 281         synchronize_rcu();
 282 }
 283
 284 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
 285                              bool mask)
 286 {
 287         struct kvm_irq_mask_notifier *kimn;
 288         struct hlist_node *n;
 289         int gsi;
 290
 291         rcu_read_lock();
 292         gsi = rcu_dereference(kvm->irq_routing)->chip[irqchip][pin];
 293         if (gsi != -1)
 294                 hlist_for_each_entry_rcu(kimn, n, &kvm->mask_notifier_list, link)
 295                         if (kimn->irq == gsi)
 296                                 kimn->func(kimn, mask);
 297         rcu_read_unlock();
 298 }
 299
 300 void kvm_free_irq_routing(struct kvm *kvm)
 301 {
 302         /* Called only during vm destruction. Nobody can use the pointer
 303            at this stage */
 304         kfree(kvm->irq_routing);
 305 }
 306
 307 static int setup_routing_entry(struct kvm_irq_routing_table *rt,
 308                                struct kvm_kernel_irq_routing_entry *e,
 309                                const struct kvm_irq_routing_entry *ue)
 310 {
 311         int r = -EINVAL;
 312         int delta;
 313         unsigned max_pin;
 314         struct kvm_kernel_irq_routing_entry *ei;
 315         struct hlist_node *n;
 316
 317         /*
 318          * Do not allow GSI to be mapped to the same irqchip more than once.
 319          * Allow only one to one mapping between GSI and MSI.
 320          */
 321         hlist_for_each_entry(ei, n, &rt->map[ue->gsi], link)
 322                 if (ei->type == KVM_IRQ_ROUTING_MSI ||
 323                     ue->type == KVM_IRQ_ROUTING_MSI ||
 324                     ue->u.irqchip.irqchip == ei->irqchip.irqchip)
 325                         return r;
 326
 327         e->gsi = ue->gsi;
 328         e->type = ue->type;
 329         switch (ue->type) {
 330         case KVM_IRQ_ROUTING_IRQCHIP:
 331                 delta = 0;
 332                 switch (ue->u.irqchip.irqchip) {
 333                 case KVM_IRQCHIP_PIC_MASTER:
 334                         e->set = kvm_set_pic_irq;
 335                         max_pin = PIC_NUM_PINS;
 336                         break;
 337                 case KVM_IRQCHIP_PIC_SLAVE:
 338                         e->set = kvm_set_pic_irq;
 339                         max_pin = PIC_NUM_PINS;
 340                         delta = 8;
 341                         break;
 342                 case KVM_IRQCHIP_IOAPIC:
 343                         max_pin = KVM_IOAPIC_NUM_PINS;
 344                         e->set = kvm_set_ioapic_irq;
 345                         break;
 346                 default:
 347                         goto out;
 348                 }
 349                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 350                 e->irqchip.pin = ue->u.irqchip.pin + delta;
 351                 if (e->irqchip.pin >= max_pin)
 352                         goto out;
 353                 rt->chip[ue->u.irqchip.irqchip][e->irqchip.pin] = ue->gsi;
 354                 break;
 355         case KVM_IRQ_ROUTING_MSI:
 356                 e->set = kvm_set_msi;
 357                 e->msi.address_lo = ue->u.msi.address_lo;
 358                 e->msi.address_hi = ue->u.msi.address_hi;
 359                 e->msi.data = ue->u.msi.data;
 360                 break;
 361         default:
 362                 goto out;
 363         }
 364
 365         hlist_add_head(&e->link, &rt->map[e->gsi]);
 366         r = 0;
 367 out:
 368         return r;
 369 }
 370
 371
 372 int kvm_set_irq_routing(struct kvm *kvm,
 373                         const struct kvm_irq_routing_entry *ue,
 374                         unsigned nr,
 375                         unsigned flags)
 376 {
 377         struct kvm_irq_routing_table *new, *old;
 378         u32 i, j, nr_rt_entries = 0;
 379         int r;
 380
 381         for (i = 0; i < nr; ++i) {
 382                 if (ue[i].gsi >= KVM_MAX_IRQ_ROUTES)
 383                         return -EINVAL;
 384                 nr_rt_entries = max(nr_rt_entries, ue[i].gsi);
 385         }
 386
 387         nr_rt_entries += 1;
 388
 389         new = kzalloc(sizeof(*new) + (nr_rt_entries * sizeof(struct hlist_head))
 390                       + (nr * sizeof(struct kvm_kernel_irq_routing_entry)),
 391                       GFP_KERNEL);
 392
 393         if (!new)
 394                 return -ENOMEM;
 395
 396         new->rt_entries = (void *)&new->map[nr_rt_entries];
 397
 398         new->nr_rt_entries = nr_rt_entries;
 399         for (i = 0; i < 3; i++)
 400                 for (j = 0; j < KVM_IOAPIC_NUM_PINS; j++)
 401                         new->chip[i][j] = -1;
 402
 403         for (i = 0; i < nr; ++i) {
 404                 r = -EINVAL;
 405                 if (ue->flags)
 406                         goto out;
 407                 r = setup_routing_entry(new, &new->rt_entries[i], ue);
 408                 if (r)
 409                         goto out;
 410                 ++ue;
 411         }
 412
 413         mutex_lock(&kvm->irq_lock);
 414         old = kvm->irq_routing;
 415         kvm_irq_routing_update(kvm, new);
 416         mutex_unlock(&kvm->irq_lock);
 417
 418         synchronize_rcu();
 419
 420         new = old;
 421         r = 0;
 422
 423 out:
 424         kfree(new);
 425         return r;
 426 }
 427
 428 #define IOAPIC_ROUTING_ENTRY(irq) \
 429         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 430           .u.irqchip.irqchip = KVM_IRQCHIP_IOAPIC, .u.irqchip.pin = (irq) }
 431 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 432
 433 #ifdef CONFIG_X86
 434 #  define PIC_ROUTING_ENTRY(irq) \
 435         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 436           .u.irqchip.irqchip = SELECT_PIC(irq), .u.irqchip.pin = (irq) % 8 }
 437 #  define ROUTING_ENTRY2(irq) \
 438         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 439 #else
 440 #  define ROUTING_ENTRY2(irq) \
 441         IOAPIC_ROUTING_ENTRY(irq)
 442 #endif
 443
 444 static const struct kvm_irq_routing_entry default_routing[] = {
 445         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 446         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 447         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 448         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 449         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 450         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 451         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 452         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 453         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 454         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 455         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 456         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 457 #ifdef CONFIG_IA64
 458         ROUTING_ENTRY1(24), ROUTING_ENTRY1(25),
 459         ROUTING_ENTRY1(26), ROUTING_ENTRY1(27),
 460         ROUTING_ENTRY1(28), ROUTING_ENTRY1(29),
 461         ROUTING_ENTRY1(30), ROUTING_ENTRY1(31),
 462         ROUTING_ENTRY1(32), ROUTING_ENTRY1(33),
 463         ROUTING_ENTRY1(34), ROUTING_ENTRY1(35),
 464         ROUTING_ENTRY1(36), ROUTING_ENTRY1(37),
 465         ROUTING_ENTRY1(38), ROUTING_ENTRY1(39),
 466         ROUTING_ENTRY1(40), ROUTING_ENTRY1(41),
 467         ROUTING_ENTRY1(42), ROUTING_ENTRY1(43),
 468         ROUTING_ENTRY1(44), ROUTING_ENTRY1(45),
 469         ROUTING_ENTRY1(46), ROUTING_ENTRY1(47),
 470 #endif
 471 };
 472
 473 int kvm_setup_default_irq_routing(struct kvm *kvm)
 474 {
 475         return kvm_set_irq_routing(kvm, default_routing,
 476                                    ARRAY_SIZE(default_routing), 0);
 477 }