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 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, BITS_PER_LONG);
 209
 210         if (irq_source_id >= BITS_PER_LONG) {
 211                 printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
 212                 irq_source_id = -EFAULT;
 213                 goto unlock;
 214         }
 215
 216         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 217         set_bit(irq_source_id, bitmap);
 218 unlock:
 219         mutex_unlock(&kvm->irq_lock);
 220
 221         return irq_source_id;
 222 }
 223
 224 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 225 {
 226         int i;
 227
 228         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 229
 230         mutex_lock(&kvm->irq_lock);
 231         if (irq_source_id < 0 ||
 232             irq_source_id >= BITS_PER_LONG) {
 233                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 234                 goto unlock;
 235         }
 236         for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
 237                 clear_bit(irq_source_id, &kvm->arch.irq_states[i]);
 238         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 239 unlock:
 240         mutex_unlock(&kvm->irq_lock);
 241 }
 242
 243 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 244                                     struct kvm_irq_mask_notifier *kimn)
 245 {
 246         mutex_lock(&kvm->irq_lock);
 247         kimn->irq = irq;
 248         hlist_add_head(&kimn->link, &kvm->mask_notifier_list);
 249         mutex_unlock(&kvm->irq_lock);
 250 }
 251
 252 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 253                                       struct kvm_irq_mask_notifier *kimn)
 254 {
 255         mutex_lock(&kvm->irq_lock);
 256         hlist_del(&kimn->link);
 257         mutex_unlock(&kvm->irq_lock);
 258 }
 259
 260 void kvm_fire_mask_notifiers(struct kvm *kvm, int irq, bool mask)
 261 {
 262         struct kvm_irq_mask_notifier *kimn;
 263         struct hlist_node *n;
 264
 265         WARN_ON(!mutex_is_locked(&kvm->irq_lock));
 266
 267         hlist_for_each_entry(kimn, n, &kvm->mask_notifier_list, link)
 268                 if (kimn->irq == irq)
 269                         kimn->func(kimn, mask);
 270 }
 271
 272 static void __kvm_free_irq_routing(struct list_head *irq_routing)
 273 {
 274         struct kvm_kernel_irq_routing_entry *e, *n;
 275
 276         list_for_each_entry_safe(e, n, irq_routing, link)
 277                 kfree(e);
 278 }
 279
 280 void kvm_free_irq_routing(struct kvm *kvm)
 281 {
 282         mutex_lock(&kvm->irq_lock);
 283         __kvm_free_irq_routing(&kvm->irq_routing);
 284         mutex_unlock(&kvm->irq_lock);
 285 }
 286
 287 static int setup_routing_entry(struct kvm_kernel_irq_routing_entry *e,
 288                                const struct kvm_irq_routing_entry *ue)
 289 {
 290         int r = -EINVAL;
 291         int delta;
 292
 293         e->gsi = ue->gsi;
 294         e->type = ue->type;
 295         switch (ue->type) {
 296         case KVM_IRQ_ROUTING_IRQCHIP:
 297                 delta = 0;
 298                 switch (ue->u.irqchip.irqchip) {
 299                 case KVM_IRQCHIP_PIC_MASTER:
 300                         e->set = kvm_set_pic_irq;
 301                         break;
 302                 case KVM_IRQCHIP_PIC_SLAVE:
 303                         e->set = kvm_set_pic_irq;
 304                         delta = 8;
 305                         break;
 306                 case KVM_IRQCHIP_IOAPIC:
 307                         e->set = kvm_set_ioapic_irq;
 308                         break;
 309                 default:
 310                         goto out;
 311                 }
 312                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 313                 e->irqchip.pin = ue->u.irqchip.pin + delta;
 314                 break;
 315         case KVM_IRQ_ROUTING_MSI:
 316                 e->set = kvm_set_msi;
 317                 e->msi.address_lo = ue->u.msi.address_lo;
 318                 e->msi.address_hi = ue->u.msi.address_hi;
 319                 e->msi.data = ue->u.msi.data;
 320                 break;
 321         default:
 322                 goto out;
 323         }
 324         r = 0;
 325 out:
 326         return r;
 327 }
 328
 329
 330 int kvm_set_irq_routing(struct kvm *kvm,
 331                         const struct kvm_irq_routing_entry *ue,
 332                         unsigned nr,
 333                         unsigned flags)
 334 {
 335         struct list_head irq_list = LIST_HEAD_INIT(irq_list);
 336         struct list_head tmp = LIST_HEAD_INIT(tmp);
 337         struct kvm_kernel_irq_routing_entry *e = NULL;
 338         unsigned i;
 339         int r;
 340
 341         for (i = 0; i < nr; ++i) {
 342                 r = -EINVAL;
 343                 if (ue->gsi >= KVM_MAX_IRQ_ROUTES)
 344                         goto out;
 345                 if (ue->flags)
 346                         goto out;
 347                 r = -ENOMEM;
 348                 e = kzalloc(sizeof(*e), GFP_KERNEL);
 349                 if (!e)
 350                         goto out;
 351                 r = setup_routing_entry(e, ue);
 352                 if (r)
 353                         goto out;
 354                 ++ue;
 355                 list_add(&e->link, &irq_list);
 356                 e = NULL;
 357         }
 358
 359         mutex_lock(&kvm->irq_lock);
 360         list_splice(&kvm->irq_routing, &tmp);
 361         INIT_LIST_HEAD(&kvm->irq_routing);
 362         list_splice(&irq_list, &kvm->irq_routing);
 363         INIT_LIST_HEAD(&irq_list);
 364         list_splice(&tmp, &irq_list);
 365         mutex_unlock(&kvm->irq_lock);
 366
 367         r = 0;
 368
 369 out:
 370         kfree(e);
 371         __kvm_free_irq_routing(&irq_list);
 372         return r;
 373 }
 374
 375 #define IOAPIC_ROUTING_ENTRY(irq) \
 376         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 377           .u.irqchip.irqchip = KVM_IRQCHIP_IOAPIC, .u.irqchip.pin = (irq) }
 378 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 379
 380 #ifdef CONFIG_X86
 381 #  define PIC_ROUTING_ENTRY(irq) \
 382         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 383           .u.irqchip.irqchip = SELECT_PIC(irq), .u.irqchip.pin = (irq) % 8 }
 384 #  define ROUTING_ENTRY2(irq) \
 385         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 386 #else
 387 #  define ROUTING_ENTRY2(irq) \
 388         IOAPIC_ROUTING_ENTRY(irq)
 389 #endif
 390
 391 static const struct kvm_irq_routing_entry default_routing[] = {
 392         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 393         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 394         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 395         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 396         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 397         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 398         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 399         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 400         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 401         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 402         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 403         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 404 #ifdef CONFIG_IA64
 405         ROUTING_ENTRY1(24), ROUTING_ENTRY1(25),
 406         ROUTING_ENTRY1(26), ROUTING_ENTRY1(27),
 407         ROUTING_ENTRY1(28), ROUTING_ENTRY1(29),
 408         ROUTING_ENTRY1(30), ROUTING_ENTRY1(31),
 409         ROUTING_ENTRY1(32), ROUTING_ENTRY1(33),
 410         ROUTING_ENTRY1(34), ROUTING_ENTRY1(35),
 411         ROUTING_ENTRY1(36), ROUTING_ENTRY1(37),
 412         ROUTING_ENTRY1(38), ROUTING_ENTRY1(39),
 413         ROUTING_ENTRY1(40), ROUTING_ENTRY1(41),
 414         ROUTING_ENTRY1(42), ROUTING_ENTRY1(43),
 415         ROUTING_ENTRY1(44), ROUTING_ENTRY1(45),
 416         ROUTING_ENTRY1(46), ROUTING_ENTRY1(47),
 417 #endif
 418 };
 419
 420 int kvm_setup_default_irq_routing(struct kvm *kvm)
 421 {
 422         return kvm_set_irq_routing(kvm, default_routing,
 423                                    ARRAY_SIZE(default_routing), 0);
 424 }