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