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->type == KVM_IRQ_ROUTING_IRQCHIP &&
 145                     e->irqchip.irqchip == irqchip &&
 146                     e->irqchip.pin == pin) {
 147                         gsi = e->gsi;
 148                         break;
 149                 }
 150
 151         hlist_for_each_entry(kian, n, &kvm->arch.irq_ack_notifier_list, link)
 152                 if (kian->gsi == gsi)
 153                         kian->irq_acked(kian);
 154 }
 155
 156 void kvm_register_irq_ack_notifier(struct kvm *kvm,
 157                                    struct kvm_irq_ack_notifier *kian)
 158 {
 159         hlist_add_head(&kian->link, &kvm->arch.irq_ack_notifier_list);
 160 }
 161
 162 void kvm_unregister_irq_ack_notifier(struct kvm_irq_ack_notifier *kian)
 163 {
 164         hlist_del_init(&kian->link);
 165 }
 166
 167 /* The caller must hold kvm->lock mutex */
 168 int kvm_request_irq_source_id(struct kvm *kvm)
 169 {
 170         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
 171         int irq_source_id = find_first_zero_bit(bitmap,
 172                                 sizeof(kvm->arch.irq_sources_bitmap));
 173
 174         if (irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
 175                 printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
 176                 return -EFAULT;
 177         }
 178
 179         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 180         set_bit(irq_source_id, bitmap);
 181
 182         return irq_source_id;
 183 }
 184
 185 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 186 {
 187         int i;
 188
 189         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 190
 191         if (irq_source_id < 0 ||
 192             irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
 193                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 194                 return;
 195         }
 196         for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
 197                 clear_bit(irq_source_id, &kvm->arch.irq_states[i]);
 198         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 199 }
 200
 201 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 202                                     struct kvm_irq_mask_notifier *kimn)
 203 {
 204         kimn->irq = irq;
 205         hlist_add_head(&kimn->link, &kvm->mask_notifier_list);
 206 }
 207
 208 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 209                                       struct kvm_irq_mask_notifier *kimn)
 210 {
 211         hlist_del(&kimn->link);
 212 }
 213
 214 void kvm_fire_mask_notifiers(struct kvm *kvm, int irq, bool mask)
 215 {
 216         struct kvm_irq_mask_notifier *kimn;
 217         struct hlist_node *n;
 218
 219         hlist_for_each_entry(kimn, n, &kvm->mask_notifier_list, link)
 220                 if (kimn->irq == irq)
 221                         kimn->func(kimn, mask);
 222 }
 223
 224 static void __kvm_free_irq_routing(struct list_head *irq_routing)
 225 {
 226         struct kvm_kernel_irq_routing_entry *e, *n;
 227
 228         list_for_each_entry_safe(e, n, irq_routing, link)
 229                 kfree(e);
 230 }
 231
 232 void kvm_free_irq_routing(struct kvm *kvm)
 233 {
 234         __kvm_free_irq_routing(&kvm->irq_routing);
 235 }
 236
 237 static int setup_routing_entry(struct kvm_kernel_irq_routing_entry *e,
 238                                const struct kvm_irq_routing_entry *ue)
 239 {
 240         int r = -EINVAL;
 241         int delta;
 242
 243         e->gsi = ue->gsi;
 244         e->type = ue->type;
 245         switch (ue->type) {
 246         case KVM_IRQ_ROUTING_IRQCHIP:
 247                 delta = 0;
 248                 switch (ue->u.irqchip.irqchip) {
 249                 case KVM_IRQCHIP_PIC_MASTER:
 250                         e->set = kvm_set_pic_irq;
 251                         break;
 252                 case KVM_IRQCHIP_PIC_SLAVE:
 253                         e->set = kvm_set_pic_irq;
 254                         delta = 8;
 255                         break;
 256                 case KVM_IRQCHIP_IOAPIC:
 257                                 e->set = kvm_set_ioapic_irq;
 258                         break;
 259                 default:
 260                         goto out;
 261                 }
 262                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 263                 e->irqchip.pin = ue->u.irqchip.pin + delta;
 264                 break;
 265         case KVM_IRQ_ROUTING_MSI:
 266                 e->set = kvm_set_msi;
 267                 e->msi.address_lo = ue->u.msi.address_lo;
 268                 e->msi.address_hi = ue->u.msi.address_hi;
 269                 e->msi.data = ue->u.msi.data;
 270                 break;
 271         default:
 272                 goto out;
 273         }
 274         r = 0;
 275 out:
 276         return r;
 277 }
 278
 279
 280 int kvm_set_irq_routing(struct kvm *kvm,
 281                         const struct kvm_irq_routing_entry *ue,
 282                         unsigned nr,
 283                         unsigned flags)
 284 {
 285         struct list_head irq_list = LIST_HEAD_INIT(irq_list);
 286         struct list_head tmp = LIST_HEAD_INIT(tmp);
 287         struct kvm_kernel_irq_routing_entry *e = NULL;
 288         unsigned i;
 289         int r;
 290
 291         for (i = 0; i < nr; ++i) {
 292                 r = -EINVAL;
 293                 if (ue->gsi >= KVM_MAX_IRQ_ROUTES)
 294                         goto out;
 295                 if (ue->flags)
 296                         goto out;
 297                 r = -ENOMEM;
 298                 e = kzalloc(sizeof(*e), GFP_KERNEL);
 299                 if (!e)
 300                         goto out;
 301                 r = setup_routing_entry(e, ue);
 302                 if (r)
 303                         goto out;
 304                 ++ue;
 305                 list_add(&e->link, &irq_list);
 306                 e = NULL;
 307         }
 308
 309         mutex_lock(&kvm->lock);
 310         list_splice(&kvm->irq_routing, &tmp);
 311         INIT_LIST_HEAD(&kvm->irq_routing);
 312         list_splice(&irq_list, &kvm->irq_routing);
 313         INIT_LIST_HEAD(&irq_list);
 314         list_splice(&tmp, &irq_list);
 315         mutex_unlock(&kvm->lock);
 316
 317         r = 0;
 318
 319 out:
 320         kfree(e);
 321         __kvm_free_irq_routing(&irq_list);
 322         return r;
 323 }
 324
 325 #define IOAPIC_ROUTING_ENTRY(irq) \
 326         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 327           .u.irqchip.irqchip = KVM_IRQCHIP_IOAPIC, .u.irqchip.pin = (irq) }
 328 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 329
 330 #ifdef CONFIG_X86
 331 #  define PIC_ROUTING_ENTRY(irq) \
 332         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 333           .u.irqchip.irqchip = SELECT_PIC(irq), .u.irqchip.pin = (irq) % 8 }
 334 #  define ROUTING_ENTRY2(irq) \
 335         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 336 #else
 337 #  define ROUTING_ENTRY2(irq) \
 338         IOAPIC_ROUTING_ENTRY(irq)
 339 #endif
 340
 341 static const struct kvm_irq_routing_entry default_routing[] = {
 342         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 343         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 344         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 345         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 346         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 347         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 348         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 349         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 350         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 351         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 352         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 353         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 354 #ifdef CONFIG_IA64
 355         ROUTING_ENTRY1(24), ROUTING_ENTRY1(25),
 356         ROUTING_ENTRY1(26), ROUTING_ENTRY1(27),
 357         ROUTING_ENTRY1(28), ROUTING_ENTRY1(29),
 358         ROUTING_ENTRY1(30), ROUTING_ENTRY1(31),
 359         ROUTING_ENTRY1(32), ROUTING_ENTRY1(33),
 360         ROUTING_ENTRY1(34), ROUTING_ENTRY1(35),
 361         ROUTING_ENTRY1(36), ROUTING_ENTRY1(37),
 362         ROUTING_ENTRY1(38), ROUTING_ENTRY1(39),
 363         ROUTING_ENTRY1(40), ROUTING_ENTRY1(41),
 364         ROUTING_ENTRY1(42), ROUTING_ENTRY1(43),
 365         ROUTING_ENTRY1(44), ROUTING_ENTRY1(45),
 366         ROUTING_ENTRY1(46), ROUTING_ENTRY1(47),
 367 #endif
 368 };
 369
 370 int kvm_setup_default_irq_routing(struct kvm *kvm)
 371 {
 372         return kvm_set_irq_routing(kvm, default_routing,
 373                                    ARRAY_SIZE(default_routing), 0);
 374 }