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