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  */
  21
  22 #include <linux/kvm_host.h>
  23 #include <trace/events/kvm.h>
  24
  25 #include <asm/msidef.h>
  26 #ifdef CONFIG_IA64
  27 #include <asm/iosapic.h>
  28 #endif
  29
  30 #include "irq.h"
  31
  32 #include "ioapic.h"
  33
  34 static inline int kvm_irq_line_state(unsigned long *irq_state,
  35                                      int irq_source_id, int level)
  36 {
  37         /* Logical OR for level trig interrupt */
  38         if (level)
  39                 set_bit(irq_source_id, irq_state);
  40         else
  41                 clear_bit(irq_source_id, irq_state);
  42
  43         return !!(*irq_state);
  44 }
  45
  46 static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
  47                            struct kvm *kvm, int irq_source_id, int level)
  48 {
  49 #ifdef CONFIG_X86
  50         struct kvm_pic *pic = pic_irqchip(kvm);
  51         level = kvm_irq_line_state(&pic->irq_states[e->irqchip.pin],
  52                                    irq_source_id, level);
  53         return kvm_pic_set_irq(pic, e->irqchip.pin, level);
  54 #else
  55         return -1;
  56 #endif
  57 }
  58
  59 static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
  60                               struct kvm *kvm, int irq_source_id, int level)
  61 {
  62         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
  63         level = kvm_irq_line_state(&ioapic->irq_states[e->irqchip.pin],
  64                                    irq_source_id, level);
  65
  66         return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, level);
  67 }
  68
  69 inline static bool kvm_is_dm_lowest_prio(struct kvm_lapic_irq *irq)
  70 {
  71 #ifdef CONFIG_IA64
  72         return irq->delivery_mode ==
  73                 (IOSAPIC_LOWEST_PRIORITY << IOSAPIC_DELIVERY_SHIFT);
  74 #else
  75         return irq->delivery_mode == APIC_DM_LOWEST;
  76 #endif
  77 }
  78
  79 int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
  80                 struct kvm_lapic_irq *irq)
  81 {
  82         int i, r = -1;
  83         struct kvm_vcpu *vcpu, *lowest = NULL;
  84
  85         if (irq->dest_mode == 0 && irq->dest_id == 0xff &&
  86                         kvm_is_dm_lowest_prio(irq))
  87                 printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
  88
  89         kvm_for_each_vcpu(i, vcpu, kvm) {
  90                 if (!kvm_apic_present(vcpu))
  91                         continue;
  92
  93                 if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
  94                                         irq->dest_id, irq->dest_mode))
  95                         continue;
  96
  97                 if (!kvm_is_dm_lowest_prio(irq)) {
  98                         if (r < 0)
  99                                 r = 0;
 100                         r += kvm_apic_set_irq(vcpu, irq);
 101                 } else {
 102                         if (!lowest)
 103                                 lowest = vcpu;
 104                         else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
 105                                 lowest = vcpu;
 106                 }
 107         }
 108
 109         if (lowest)
 110                 r = kvm_apic_set_irq(lowest, irq);
 111
 112         return r;
 113 }
 114
 115 static int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
 116                        struct kvm *kvm, int irq_source_id, int level)
 117 {
 118         struct kvm_lapic_irq irq;
 119
 120         if (!level)
 121                 return -1;
 122
 123         trace_kvm_msi_set_irq(e->msi.address_lo, e->msi.data);
 124
 125         irq.dest_id = (e->msi.address_lo &
 126                         MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
 127         irq.vector = (e->msi.data &
 128                         MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
 129         irq.dest_mode = (1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo;
 130         irq.trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
 131         irq.delivery_mode = e->msi.data & 0x700;
 132         irq.level = 1;
 133         irq.shorthand = 0;
 134
 135         /* TODO Deal with RH bit of MSI message address */
 136         return kvm_irq_delivery_to_apic(kvm, NULL, &irq);
 137 }
 138
 139 /*
 140  * Return value:
 141  *  < 0   Interrupt was ignored (masked or not delivered for other reasons)
 142  *  = 0   Interrupt was coalesced (previous irq is still pending)
 143  *  > 0   Number of CPUs interrupt was delivered to
 144  */
 145 int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level)
 146 {
 147         struct kvm_kernel_irq_routing_entry *e, irq_set[KVM_NR_IRQCHIPS];
 148         int ret = -1, i = 0;
 149         struct kvm_irq_routing_table *irq_rt;
 150         struct hlist_node *n;
 151
 152         trace_kvm_set_irq(irq, level, irq_source_id);
 153
 154         /* Not possible to detect if the guest uses the PIC or the
 155          * IOAPIC.  So set the bit in both. The guest will ignore
 156          * writes to the unused one.
 157          */
 158         rcu_read_lock();
 159         irq_rt = rcu_dereference(kvm->irq_routing);
 160         if (irq < irq_rt->nr_rt_entries)
 161                 hlist_for_each_entry(e, n, &irq_rt->map[irq], link)
 162                         irq_set[i++] = *e;
 163         rcu_read_unlock();
 164
 165         while(i--) {
 166                 int r;
 167                 r = irq_set[i].set(&irq_set[i], kvm, irq_source_id, level);
 168                 if (r < 0)
 169                         continue;
 170
 171                 ret = r + ((ret < 0) ? 0 : ret);
 172         }
 173
 174         return ret;
 175 }
 176
 177 void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
 178 {
 179         struct kvm_irq_ack_notifier *kian;
 180         struct hlist_node *n;
 181         int gsi;
 182
 183         trace_kvm_ack_irq(irqchip, pin);
 184
 185         rcu_read_lock();
 186         gsi = rcu_dereference(kvm->irq_routing)->chip[irqchip][pin];
 187         if (gsi != -1)
 188                 hlist_for_each_entry_rcu(kian, n, &kvm->irq_ack_notifier_list,
 189                                          link)
 190                         if (kian->gsi == gsi)
 191                                 kian->irq_acked(kian);
 192         rcu_read_unlock();
 193 }
 194
 195 void kvm_register_irq_ack_notifier(struct kvm *kvm,
 196                                    struct kvm_irq_ack_notifier *kian)
 197 {
 198         mutex_lock(&kvm->irq_lock);
 199         hlist_add_head_rcu(&kian->link, &kvm->irq_ack_notifier_list);
 200         mutex_unlock(&kvm->irq_lock);
 201 }
 202
 203 void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
 204                                     struct kvm_irq_ack_notifier *kian)
 205 {
 206         mutex_lock(&kvm->irq_lock);
 207         hlist_del_init_rcu(&kian->link);
 208         mutex_unlock(&kvm->irq_lock);
 209         synchronize_rcu();
 210 }
 211
 212 int kvm_request_irq_source_id(struct kvm *kvm)
 213 {
 214         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
 215         int irq_source_id;
 216
 217         mutex_lock(&kvm->irq_lock);
 218         irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
 219
 220         if (irq_source_id >= BITS_PER_LONG) {
 221                 printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
 222                 irq_source_id = -EFAULT;
 223                 goto unlock;
 224         }
 225
 226         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 227         set_bit(irq_source_id, bitmap);
 228 unlock:
 229         mutex_unlock(&kvm->irq_lock);
 230
 231         return irq_source_id;
 232 }
 233
 234 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 235 {
 236         int i;
 237
 238         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 239
 240         mutex_lock(&kvm->irq_lock);
 241         if (irq_source_id < 0 ||
 242             irq_source_id >= BITS_PER_LONG) {
 243                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 244                 goto unlock;
 245         }
 246         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 247         if (!irqchip_in_kernel(kvm))
 248                 goto unlock;
 249
 250         for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++) {
 251                 clear_bit(irq_source_id, &kvm->arch.vioapic->irq_states[i]);
 252                 if (i >= 16)
 253                         continue;
 254 #ifdef CONFIG_X86
 255                 clear_bit(irq_source_id, &pic_irqchip(kvm)->irq_states[i]);
 256 #endif
 257         }
 258 unlock:
 259         mutex_unlock(&kvm->irq_lock);
 260 }
 261
 262 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 263                                     struct kvm_irq_mask_notifier *kimn)
 264 {
 265         mutex_lock(&kvm->irq_lock);
 266         kimn->irq = irq;
 267         hlist_add_head_rcu(&kimn->link, &kvm->mask_notifier_list);
 268         mutex_unlock(&kvm->irq_lock);
 269 }
 270
 271 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 272                                       struct kvm_irq_mask_notifier *kimn)
 273 {
 274         mutex_lock(&kvm->irq_lock);
 275         hlist_del_rcu(&kimn->link);
 276         mutex_unlock(&kvm->irq_lock);
 277         synchronize_rcu();
 278 }
 279
 280 void kvm_fire_mask_notifiers(struct kvm *kvm, int irq, bool mask)
 281 {
 282         struct kvm_irq_mask_notifier *kimn;
 283         struct hlist_node *n;
 284
 285         rcu_read_lock();
 286         hlist_for_each_entry_rcu(kimn, n, &kvm->mask_notifier_list, link)
 287                 if (kimn->irq == irq)
 288                         kimn->func(kimn, mask);
 289         rcu_read_unlock();
 290 }
 291
 292 void kvm_free_irq_routing(struct kvm *kvm)
 293 {
 294         /* Called only during vm destruction. Nobody can use the pointer
 295            at this stage */
 296         kfree(kvm->irq_routing);
 297 }
 298
 299 static int setup_routing_entry(struct kvm_irq_routing_table *rt,
 300                                struct kvm_kernel_irq_routing_entry *e,
 301                                const struct kvm_irq_routing_entry *ue)
 302 {
 303         int r = -EINVAL;
 304         int delta;
 305         unsigned max_pin;
 306         struct kvm_kernel_irq_routing_entry *ei;
 307         struct hlist_node *n;
 308
 309         /*
 310          * Do not allow GSI to be mapped to the same irqchip more than once.
 311          * Allow only one to one mapping between GSI and MSI.
 312          */
 313         hlist_for_each_entry(ei, n, &rt->map[ue->gsi], link)
 314                 if (ei->type == KVM_IRQ_ROUTING_MSI ||
 315                     ue->u.irqchip.irqchip == ei->irqchip.irqchip)
 316                         return r;
 317
 318         e->gsi = ue->gsi;
 319         e->type = ue->type;
 320         switch (ue->type) {
 321         case KVM_IRQ_ROUTING_IRQCHIP:
 322                 delta = 0;
 323                 switch (ue->u.irqchip.irqchip) {
 324                 case KVM_IRQCHIP_PIC_MASTER:
 325                         e->set = kvm_set_pic_irq;
 326                         max_pin = 16;
 327                         break;
 328                 case KVM_IRQCHIP_PIC_SLAVE:
 329                         e->set = kvm_set_pic_irq;
 330                         max_pin = 16;
 331                         delta = 8;
 332                         break;
 333                 case KVM_IRQCHIP_IOAPIC:
 334                         max_pin = KVM_IOAPIC_NUM_PINS;
 335                         e->set = kvm_set_ioapic_irq;
 336                         break;
 337                 default:
 338                         goto out;
 339                 }
 340                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 341                 e->irqchip.pin = ue->u.irqchip.pin + delta;
 342                 if (e->irqchip.pin >= max_pin)
 343                         goto out;
 344                 rt->chip[ue->u.irqchip.irqchip][e->irqchip.pin] = ue->gsi;
 345                 break;
 346         case KVM_IRQ_ROUTING_MSI:
 347                 e->set = kvm_set_msi;
 348                 e->msi.address_lo = ue->u.msi.address_lo;
 349                 e->msi.address_hi = ue->u.msi.address_hi;
 350                 e->msi.data = ue->u.msi.data;
 351                 break;
 352         default:
 353                 goto out;
 354         }
 355
 356         hlist_add_head(&e->link, &rt->map[e->gsi]);
 357         r = 0;
 358 out:
 359         return r;
 360 }
 361
 362
 363 int kvm_set_irq_routing(struct kvm *kvm,
 364                         const struct kvm_irq_routing_entry *ue,
 365                         unsigned nr,
 366                         unsigned flags)
 367 {
 368         struct kvm_irq_routing_table *new, *old;
 369         u32 i, j, nr_rt_entries = 0;
 370         int r;
 371
 372         for (i = 0; i < nr; ++i) {
 373                 if (ue[i].gsi >= KVM_MAX_IRQ_ROUTES)
 374                         return -EINVAL;
 375                 nr_rt_entries = max(nr_rt_entries, ue[i].gsi);
 376         }
 377
 378         nr_rt_entries += 1;
 379
 380         new = kzalloc(sizeof(*new) + (nr_rt_entries * sizeof(struct hlist_head))
 381                       + (nr * sizeof(struct kvm_kernel_irq_routing_entry)),
 382                       GFP_KERNEL);
 383
 384         if (!new)
 385                 return -ENOMEM;
 386
 387         new->rt_entries = (void *)&new->map[nr_rt_entries];
 388
 389         new->nr_rt_entries = nr_rt_entries;
 390         for (i = 0; i < 3; i++)
 391                 for (j = 0; j < KVM_IOAPIC_NUM_PINS; j++)
 392                         new->chip[i][j] = -1;
 393
 394         for (i = 0; i < nr; ++i) {
 395                 r = -EINVAL;
 396                 if (ue->flags)
 397                         goto out;
 398                 r = setup_routing_entry(new, &new->rt_entries[i], ue);
 399                 if (r)
 400                         goto out;
 401                 ++ue;
 402         }
 403
 404         mutex_lock(&kvm->irq_lock);
 405         old = kvm->irq_routing;
 406         rcu_assign_pointer(kvm->irq_routing, new);
 407         mutex_unlock(&kvm->irq_lock);
 408         synchronize_rcu();
 409
 410         new = old;
 411         r = 0;
 412
 413 out:
 414         kfree(new);
 415         return r;
 416 }
 417
 418 #define IOAPIC_ROUTING_ENTRY(irq) \
 419         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 420           .u.irqchip.irqchip = KVM_IRQCHIP_IOAPIC, .u.irqchip.pin = (irq) }
 421 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 422
 423 #ifdef CONFIG_X86
 424 #  define PIC_ROUTING_ENTRY(irq) \
 425         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 426           .u.irqchip.irqchip = SELECT_PIC(irq), .u.irqchip.pin = (irq) % 8 }
 427 #  define ROUTING_ENTRY2(irq) \
 428         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 429 #else
 430 #  define ROUTING_ENTRY2(irq) \
 431         IOAPIC_ROUTING_ENTRY(irq)
 432 #endif
 433
 434 static const struct kvm_irq_routing_entry default_routing[] = {
 435         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 436         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 437         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 438         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 439         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 440         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 441         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 442         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 443         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 444         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 445         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 446         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 447 #ifdef CONFIG_IA64
 448         ROUTING_ENTRY1(24), ROUTING_ENTRY1(25),
 449         ROUTING_ENTRY1(26), ROUTING_ENTRY1(27),
 450         ROUTING_ENTRY1(28), ROUTING_ENTRY1(29),
 451         ROUTING_ENTRY1(30), ROUTING_ENTRY1(31),
 452         ROUTING_ENTRY1(32), ROUTING_ENTRY1(33),
 453         ROUTING_ENTRY1(34), ROUTING_ENTRY1(35),
 454         ROUTING_ENTRY1(36), ROUTING_ENTRY1(37),
 455         ROUTING_ENTRY1(38), ROUTING_ENTRY1(39),
 456         ROUTING_ENTRY1(40), ROUTING_ENTRY1(41),
 457         ROUTING_ENTRY1(42), ROUTING_ENTRY1(43),
 458         ROUTING_ENTRY1(44), ROUTING_ENTRY1(45),
 459         ROUTING_ENTRY1(46), ROUTING_ENTRY1(47),
 460 #endif
 461 };
 462
 463 int kvm_setup_default_irq_routing(struct kvm *kvm)
 464 {
 465         return kvm_set_irq_routing(kvm, default_routing,
 466                                    ARRAY_SIZE(default_routing), 0);
 467 }