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
  24 #include <asm/msidef.h>
  25
  26 #include "irq.h"
  27
  28 #include "ioapic.h"
  29
  30 static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
  31                            struct kvm *kvm, int level)
  32 {
  33 #ifdef CONFIG_X86
  34         return kvm_pic_set_irq(pic_irqchip(kvm), e->irqchip.pin, level);
  35 #else
  36         return -1;
  37 #endif
  38 }
  39
  40 static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
  41                               struct kvm *kvm, int level)
  42 {
  43         return kvm_ioapic_set_irq(kvm->arch.vioapic, e->irqchip.pin, level);
  44 }
  45
  46 static int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
  47                        struct kvm *kvm, int level)
  48 {
  49         int vcpu_id, r = -1;
  50         struct kvm_vcpu *vcpu;
  51         struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
  52         int dest_id = (e->msi.address_lo & MSI_ADDR_DEST_ID_MASK)
  53                         >> MSI_ADDR_DEST_ID_SHIFT;
  54         int vector = (e->msi.data & MSI_DATA_VECTOR_MASK)
  55                         >> MSI_DATA_VECTOR_SHIFT;
  56         int dest_mode = test_bit(MSI_ADDR_DEST_MODE_SHIFT,
  57                                 (unsigned long *)&e->msi.address_lo);
  58         int trig_mode = test_bit(MSI_DATA_TRIGGER_SHIFT,
  59                                 (unsigned long *)&e->msi.data);
  60         int delivery_mode = test_bit(MSI_DATA_DELIVERY_MODE_SHIFT,
  61                                 (unsigned long *)&e->msi.data);
  62         u32 deliver_bitmask;
  63
  64         BUG_ON(!ioapic);
  65
  66         deliver_bitmask = kvm_ioapic_get_delivery_bitmask(ioapic,
  67                                 dest_id, dest_mode);
  68         /* IOAPIC delivery mode value is the same as MSI here */
  69         switch (delivery_mode) {
  70         case IOAPIC_LOWEST_PRIORITY:
  71                 vcpu = kvm_get_lowest_prio_vcpu(ioapic->kvm, vector,
  72                                 deliver_bitmask);
  73                 if (vcpu != NULL)
  74                         r = kvm_apic_set_irq(vcpu, vector, trig_mode);
  75                 else
  76                         printk(KERN_INFO "kvm: null lowest priority vcpu!\n");
  77                 break;
  78         case IOAPIC_FIXED:
  79                 for (vcpu_id = 0; deliver_bitmask != 0; vcpu_id++) {
  80                         if (!(deliver_bitmask & (1 << vcpu_id)))
  81                                 continue;
  82                         deliver_bitmask &= ~(1 << vcpu_id);
  83                         vcpu = ioapic->kvm->vcpus[vcpu_id];
  84                         if (vcpu) {
  85                                 if (r < 0)
  86                                         r = 0;
  87                                 r += kvm_apic_set_irq(vcpu, vector, trig_mode);
  88                         }
  89                 }
  90                 break;
  91         default:
  92                 break;
  93         }
  94         return r;
  95 }
  96
  97 /* This should be called with the kvm->lock mutex held
  98  * Return value:
  99  *  < 0   Interrupt was ignored (masked or not delivered for other reasons)
 100  *  = 0   Interrupt was coalesced (previous irq is still pending)
 101  *  > 0   Number of CPUs interrupt was delivered to
 102  */
 103 int kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level)
 104 {
 105         struct kvm_kernel_irq_routing_entry *e;
 106         unsigned long *irq_state, sig_level;
 107         int ret = -1;
 108
 109         if (irq < KVM_IOAPIC_NUM_PINS) {
 110                 irq_state = (unsigned long *)&kvm->arch.irq_states[irq];
 111
 112                 /* Logical OR for level trig interrupt */
 113                 if (level)
 114                         set_bit(irq_source_id, irq_state);
 115                 else
 116                         clear_bit(irq_source_id, irq_state);
 117                 sig_level = !!(*irq_state);
 118         } else /* Deal with MSI/MSI-X */
 119                 sig_level = 1;
 120
 121         /* Not possible to detect if the guest uses the PIC or the
 122          * IOAPIC.  So set the bit in both. The guest will ignore
 123          * writes to the unused one.
 124          */
 125         list_for_each_entry(e, &kvm->irq_routing, link)
 126                 if (e->gsi == irq) {
 127                         int r = e->set(e, kvm, sig_level);
 128                         if (r < 0)
 129                                 continue;
 130
 131                         ret = r + ((ret < 0) ? 0 : ret);
 132                 }
 133         return ret;
 134 }
 135
 136 void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
 137 {
 138         struct kvm_kernel_irq_routing_entry *e;
 139         struct kvm_irq_ack_notifier *kian;
 140         struct hlist_node *n;
 141         unsigned gsi = pin;
 142
 143         list_for_each_entry(e, &kvm->irq_routing, link)
 144                 if (e->irqchip.irqchip == irqchip &&
 145                     e->irqchip.pin == pin) {
 146                         gsi = e->gsi;
 147                         break;
 148                 }
 149
 150         hlist_for_each_entry(kian, n, &kvm->arch.irq_ack_notifier_list, link)
 151                 if (kian->gsi == gsi)
 152                         kian->irq_acked(kian);
 153 }
 154
 155 void kvm_register_irq_ack_notifier(struct kvm *kvm,
 156                                    struct kvm_irq_ack_notifier *kian)
 157 {
 158         hlist_add_head(&kian->link, &kvm->arch.irq_ack_notifier_list);
 159 }
 160
 161 void kvm_unregister_irq_ack_notifier(struct kvm_irq_ack_notifier *kian)
 162 {
 163         hlist_del_init(&kian->link);
 164 }
 165
 166 /* The caller must hold kvm->lock mutex */
 167 int kvm_request_irq_source_id(struct kvm *kvm)
 168 {
 169         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
 170         int irq_source_id = find_first_zero_bit(bitmap,
 171                                 sizeof(kvm->arch.irq_sources_bitmap));
 172
 173         if (irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
 174                 printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
 175                 return -EFAULT;
 176         }
 177
 178         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 179         set_bit(irq_source_id, bitmap);
 180
 181         return irq_source_id;
 182 }
 183
 184 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 185 {
 186         int i;
 187
 188         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 189
 190         if (irq_source_id < 0 ||
 191             irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
 192                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 193                 return;
 194         }
 195         for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
 196                 clear_bit(irq_source_id, &kvm->arch.irq_states[i]);
 197         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 198 }
 199
 200 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 201                                     struct kvm_irq_mask_notifier *kimn)
 202 {
 203         kimn->irq = irq;
 204         hlist_add_head(&kimn->link, &kvm->mask_notifier_list);
 205 }
 206
 207 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 208                                       struct kvm_irq_mask_notifier *kimn)
 209 {
 210         hlist_del(&kimn->link);
 211 }
 212
 213 void kvm_fire_mask_notifiers(struct kvm *kvm, int irq, bool mask)
 214 {
 215         struct kvm_irq_mask_notifier *kimn;
 216         struct hlist_node *n;
 217
 218         hlist_for_each_entry(kimn, n, &kvm->mask_notifier_list, link)
 219                 if (kimn->irq == irq)
 220                         kimn->func(kimn, mask);
 221 }
 222
 223 static void __kvm_free_irq_routing(struct list_head *irq_routing)
 224 {
 225         struct kvm_kernel_irq_routing_entry *e, *n;
 226
 227         list_for_each_entry_safe(e, n, irq_routing, link)
 228                 kfree(e);
 229 }
 230
 231 void kvm_free_irq_routing(struct kvm *kvm)
 232 {
 233         __kvm_free_irq_routing(&kvm->irq_routing);
 234 }
 235
 236 static int setup_routing_entry(struct kvm_kernel_irq_routing_entry *e,
 237                                const struct kvm_irq_routing_entry *ue)
 238 {
 239         int r = -EINVAL;
 240         int delta;
 241
 242         e->gsi = ue->gsi;
 243         switch (ue->type) {
 244         case KVM_IRQ_ROUTING_IRQCHIP:
 245                 delta = 0;
 246                 switch (ue->u.irqchip.irqchip) {
 247                 case KVM_IRQCHIP_PIC_MASTER:
 248                         e->set = kvm_set_pic_irq;
 249                         break;
 250                 case KVM_IRQCHIP_PIC_SLAVE:
 251                         e->set = kvm_set_pic_irq;
 252                         delta = 8;
 253                         break;
 254                 case KVM_IRQCHIP_IOAPIC:
 255                                 e->set = kvm_set_ioapic_irq;
 256                         break;
 257                 default:
 258                         goto out;
 259                 }
 260                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 261                 e->irqchip.pin = ue->u.irqchip.pin + delta;
 262                 break;
 263         case KVM_IRQ_ROUTING_MSI:
 264                 e->set = kvm_set_msi;
 265                 e->msi.address_lo = ue->u.msi.address_lo;
 266                 e->msi.address_hi = ue->u.msi.address_hi;
 267                 e->msi.data = ue->u.msi.data;
 268                 break;
 269         default:
 270                 goto out;
 271         }
 272         r = 0;
 273 out:
 274         return r;
 275 }
 276
 277
 278 int kvm_set_irq_routing(struct kvm *kvm,
 279                         const struct kvm_irq_routing_entry *ue,
 280                         unsigned nr,
 281                         unsigned flags)
 282 {
 283         struct list_head irq_list = LIST_HEAD_INIT(irq_list);
 284         struct list_head tmp = LIST_HEAD_INIT(tmp);
 285         struct kvm_kernel_irq_routing_entry *e = NULL;
 286         unsigned i;
 287         int r;
 288
 289         for (i = 0; i < nr; ++i) {
 290                 r = -EINVAL;
 291                 if (ue->gsi >= KVM_MAX_IRQ_ROUTES)
 292                         goto out;
 293                 if (ue->flags)
 294                         goto out;
 295                 r = -ENOMEM;
 296                 e = kzalloc(sizeof(*e), GFP_KERNEL);
 297                 if (!e)
 298                         goto out;
 299                 r = setup_routing_entry(e, ue);
 300                 if (r)
 301                         goto out;
 302                 ++ue;
 303                 list_add(&e->link, &irq_list);
 304                 e = NULL;
 305         }
 306
 307         mutex_lock(&kvm->lock);
 308         list_splice(&kvm->irq_routing, &tmp);
 309         INIT_LIST_HEAD(&kvm->irq_routing);
 310         list_splice(&irq_list, &kvm->irq_routing);
 311         INIT_LIST_HEAD(&irq_list);
 312         list_splice(&tmp, &irq_list);
 313         mutex_unlock(&kvm->lock);
 314
 315         r = 0;
 316
 317 out:
 318         kfree(e);
 319         __kvm_free_irq_routing(&irq_list);
 320         return r;
 321 }
 322
 323 #define IOAPIC_ROUTING_ENTRY(irq) \
 324         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 325           .u.irqchip.irqchip = KVM_IRQCHIP_IOAPIC, .u.irqchip.pin = (irq) }
 326 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 327
 328 #ifdef CONFIG_X86
 329 #  define PIC_ROUTING_ENTRY(irq) \
 330         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 331           .u.irqchip.irqchip = SELECT_PIC(irq), .u.irqchip.pin = (irq) % 8 }
 332 #  define ROUTING_ENTRY2(irq) \
 333         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 334 #else
 335 #  define ROUTING_ENTRY2(irq) \
 336         IOAPIC_ROUTING_ENTRY(irq)
 337 #endif
 338
 339 static const struct kvm_irq_routing_entry default_routing[] = {
 340         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 341         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 342         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 343         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 344         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 345         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 346         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 347         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 348         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 349         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 350         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 351         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 352 #ifdef CONFIG_IA64
 353         ROUTING_ENTRY1(24), ROUTING_ENTRY1(25),
 354         ROUTING_ENTRY1(26), ROUTING_ENTRY1(27),
 355         ROUTING_ENTRY1(28), ROUTING_ENTRY1(29),
 356         ROUTING_ENTRY1(30), ROUTING_ENTRY1(31),
 357         ROUTING_ENTRY1(32), ROUTING_ENTRY1(33),
 358         ROUTING_ENTRY1(34), ROUTING_ENTRY1(35),
 359         ROUTING_ENTRY1(36), ROUTING_ENTRY1(37),
 360         ROUTING_ENTRY1(38), ROUTING_ENTRY1(39),
 361         ROUTING_ENTRY1(40), ROUTING_ENTRY1(41),
 362         ROUTING_ENTRY1(42), ROUTING_ENTRY1(43),
 363         ROUTING_ENTRY1(44), ROUTING_ENTRY1(45),
 364         ROUTING_ENTRY1(46), ROUTING_ENTRY1(47),
 365 #endif
 366 };
 367
 368 int kvm_setup_default_irq_routing(struct kvm *kvm)
 369 {
 370         return kvm_set_irq_routing(kvm, default_routing,
 371                                    ARRAY_SIZE(default_routing), 0);
 372 }