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