kernel/arch/x86/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  * Copyright 2010 Red Hat, Inc. and/or its affiliates.
  21  */
  22
  23 #include <linux/kvm_host.h>
  24 #include <linux/slab.h>
  25 #include <linux/export.h>
  26 #include <trace/events/kvm.h>
  27
  28 #include <asm/msidef.h>
  29
  30 #include "irq.h"
  31
  32 #include "ioapic.h"
  33
  34 #include "lapic.h"
  35
  36 static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
  37                            struct kvm *kvm, int irq_source_id, int level,
  38                            bool line_status)
  39 {
  40         struct kvm_pic *pic = pic_irqchip(kvm);
  41         return kvm_pic_set_irq(pic, e->irqchip.pin, irq_source_id, level);
  42 }
  43
  44 static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
  45                               struct kvm *kvm, int irq_source_id, int level,
  46                               bool line_status)
  47 {
  48         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
  49         return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, irq_source_id, level,
  50                                 line_status);
  51 }
  52
  53 int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
  54                 struct kvm_lapic_irq *irq, unsigned long *dest_map)
  55 {
  56         int i, r = -1;
  57         struct kvm_vcpu *vcpu, *lowest = NULL;
  58
  59         if (irq->dest_mode == 0 && irq->dest_id == 0xff &&
  60                         kvm_lowest_prio_delivery(irq)) {
  61                 printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
  62                 irq->delivery_mode = APIC_DM_FIXED;
  63         }
  64
  65         if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
  66                 return r;
  67
  68         kvm_for_each_vcpu(i, vcpu, kvm) {
  69                 if (!kvm_apic_present(vcpu))
  70                         continue;
  71
  72                 if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
  73                                         irq->dest_id, irq->dest_mode))
  74                         continue;
  75
  76                 if (!kvm_lowest_prio_delivery(irq)) {
  77                         if (r < 0)
  78                                 r = 0;
  79                         r += kvm_apic_set_irq(vcpu, irq, dest_map);
  80                 } else if (kvm_lapic_enabled(vcpu)) {
  81                         if (!lowest)
  82                                 lowest = vcpu;
  83                         else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
  84                                 lowest = vcpu;
  85                 }
  86         }
  87
  88         if (lowest)
  89                 r = kvm_apic_set_irq(lowest, irq, dest_map);
  90
  91         return r;
  92 }
  93
  94 void kvm_set_msi_irq(struct kvm_kernel_irq_routing_entry *e,
  95                      struct kvm_lapic_irq *irq)
  96 {
  97         trace_kvm_msi_set_irq(e->msi.address_lo, e->msi.data);
  98
  99         irq->dest_id = (e->msi.address_lo &
 100                         MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
 101         irq->vector = (e->msi.data &
 102                         MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
 103         irq->dest_mode = (1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo;
 104         irq->trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
 105         irq->delivery_mode = e->msi.data & 0x700;
 106         irq->msi_redir_hint = ((e->msi.address_lo
 107                 & MSI_ADDR_REDIRECTION_LOWPRI) > 0);
 108         irq->level = 1;
 109         irq->shorthand = 0;
 110 }
 111 EXPORT_SYMBOL_GPL(kvm_set_msi_irq);
 112
 113 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
 114                 struct kvm *kvm, int irq_source_id, int level, bool line_status)
 115 {
 116         struct kvm_lapic_irq irq;
 117
 118         if (!level)
 119                 return -1;
 120
 121         kvm_set_msi_irq(e, &irq);
 122
 123         return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
 124 }
 125
 126
 127 int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
 128                               struct kvm *kvm, int irq_source_id, int level,
 129                               bool line_status)
 130 {
 131         struct kvm_lapic_irq irq;
 132         int r;
 133
 134         if (unlikely(e->type != KVM_IRQ_ROUTING_MSI))
 135                 return -EWOULDBLOCK;
 136
 137         kvm_set_msi_irq(e, &irq);
 138
 139         if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
 140                 return r;
 141         else
 142                 return -EWOULDBLOCK;
 143 }
 144
 145 int kvm_request_irq_source_id(struct kvm *kvm)
 146 {
 147         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
 148         int irq_source_id;
 149
 150         mutex_lock(&kvm->irq_lock);
 151         irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
 152
 153         if (irq_source_id >= BITS_PER_LONG) {
 154                 printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
 155                 irq_source_id = -EFAULT;
 156                 goto unlock;
 157         }
 158
 159         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 160         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 161         set_bit(irq_source_id, bitmap);
 162 unlock:
 163         mutex_unlock(&kvm->irq_lock);
 164
 165         return irq_source_id;
 166 }
 167
 168 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 169 {
 170         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 171         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 172
 173         mutex_lock(&kvm->irq_lock);
 174         if (irq_source_id < 0 ||
 175             irq_source_id >= BITS_PER_LONG) {
 176                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 177                 goto unlock;
 178         }
 179         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 180         if (!ioapic_in_kernel(kvm))
 181                 goto unlock;
 182
 183         kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
 184         kvm_pic_clear_all(pic_irqchip(kvm), irq_source_id);
 185 unlock:
 186         mutex_unlock(&kvm->irq_lock);
 187 }
 188
 189 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 190                                     struct kvm_irq_mask_notifier *kimn)
 191 {
 192         mutex_lock(&kvm->irq_lock);
 193         kimn->irq = irq;
 194         hlist_add_head_rcu(&kimn->link, &kvm->arch.mask_notifier_list);
 195         mutex_unlock(&kvm->irq_lock);
 196 }
 197
 198 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 199                                       struct kvm_irq_mask_notifier *kimn)
 200 {
 201         mutex_lock(&kvm->irq_lock);
 202         hlist_del_rcu(&kimn->link);
 203         mutex_unlock(&kvm->irq_lock);
 204         synchronize_srcu(&kvm->irq_srcu);
 205 }
 206
 207 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
 208                              bool mask)
 209 {
 210         struct kvm_irq_mask_notifier *kimn;
 211         int idx, gsi;
 212
 213         idx = srcu_read_lock(&kvm->irq_srcu);
 214         gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
 215         if (gsi != -1)
 216                 hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
 217                         if (kimn->irq == gsi)
 218                                 kimn->func(kimn, mask);
 219         srcu_read_unlock(&kvm->irq_srcu, idx);
 220 }
 221
 222 int kvm_set_routing_entry(struct kvm_kernel_irq_routing_entry *e,
 223                           const struct kvm_irq_routing_entry *ue)
 224 {
 225         int r = -EINVAL;
 226         int delta;
 227         unsigned max_pin;
 228
 229         switch (ue->type) {
 230         case KVM_IRQ_ROUTING_IRQCHIP:
 231                 delta = 0;
 232                 switch (ue->u.irqchip.irqchip) {
 233                 case KVM_IRQCHIP_PIC_MASTER:
 234                         e->set = kvm_set_pic_irq;
 235                         max_pin = PIC_NUM_PINS;
 236                         break;
 237                 case KVM_IRQCHIP_PIC_SLAVE:
 238                         e->set = kvm_set_pic_irq;
 239                         max_pin = PIC_NUM_PINS;
 240                         delta = 8;
 241                         break;
 242                 case KVM_IRQCHIP_IOAPIC:
 243                         max_pin = KVM_IOAPIC_NUM_PINS;
 244                         e->set = kvm_set_ioapic_irq;
 245                         break;
 246                 default:
 247                         goto out;
 248                 }
 249                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 250                 e->irqchip.pin = ue->u.irqchip.pin + delta;
 251                 if (e->irqchip.pin >= max_pin)
 252                         goto out;
 253                 break;
 254         case KVM_IRQ_ROUTING_MSI:
 255                 e->set = kvm_set_msi;
 256                 e->msi.address_lo = ue->u.msi.address_lo;
 257                 e->msi.address_hi = ue->u.msi.address_hi;
 258                 e->msi.data = ue->u.msi.data;
 259                 break;
 260         default:
 261                 goto out;
 262         }
 263
 264         r = 0;
 265 out:
 266         return r;
 267 }
 268
 269 bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
 270                              struct kvm_vcpu **dest_vcpu)
 271 {
 272         int i, r = 0;
 273         struct kvm_vcpu *vcpu;
 274
 275         if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
 276                 return true;
 277
 278         kvm_for_each_vcpu(i, vcpu, kvm) {
 279                 if (!kvm_apic_present(vcpu))
 280                         continue;
 281
 282                 if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand,
 283                                         irq->dest_id, irq->dest_mode))
 284                         continue;
 285
 286                 if (++r == 2)
 287                         return false;
 288
 289                 *dest_vcpu = vcpu;
 290         }
 291
 292         return r == 1;
 293 }
 294 EXPORT_SYMBOL_GPL(kvm_intr_is_single_vcpu);
 295
 296 #define IOAPIC_ROUTING_ENTRY(irq) \
 297         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 298           .u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
 299 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 300
 301 #define PIC_ROUTING_ENTRY(irq) \
 302         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 303           .u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
 304 #define ROUTING_ENTRY2(irq) \
 305         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 306
 307 static const struct kvm_irq_routing_entry default_routing[] = {
 308         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 309         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 310         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 311         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 312         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 313         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 314         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 315         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 316         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 317         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 318         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 319         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 320 };
 321
 322 int kvm_setup_default_irq_routing(struct kvm *kvm)
 323 {
 324         return kvm_set_irq_routing(kvm, default_routing,
 325                                    ARRAY_SIZE(default_routing), 0);
 326 }
 327
 328 static const struct kvm_irq_routing_entry empty_routing[] = {};
 329
 330 int kvm_setup_empty_irq_routing(struct kvm *kvm)
 331 {
 332         return kvm_set_irq_routing(kvm, empty_routing, 0, 0);
 333 }
 334
 335 void kvm_arch_irq_routing_update(struct kvm *kvm)
 336 {
 337         if (ioapic_in_kernel(kvm) || !irqchip_in_kernel(kvm))
 338                 return;
 339         kvm_make_scan_ioapic_request(kvm);
 340 }
 341
 342 void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap)
 343 {
 344         struct kvm *kvm = vcpu->kvm;
 345         struct kvm_kernel_irq_routing_entry *entry;
 346         struct kvm_irq_routing_table *table;
 347         u32 i, nr_ioapic_pins;
 348         int idx;
 349
 350         /* kvm->irq_routing must be read after clearing
 351          * KVM_SCAN_IOAPIC. */
 352         smp_mb();
 353         idx = srcu_read_lock(&kvm->irq_srcu);
 354         table = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
 355         nr_ioapic_pins = min_t(u32, table->nr_rt_entries,
 356                                kvm->arch.nr_reserved_ioapic_pins);
 357         for (i = 0; i < nr_ioapic_pins; ++i) {
 358                 hlist_for_each_entry(entry, &table->map[i], link) {
 359                         u32 dest_id, dest_mode;
 360                         bool level;
 361
 362                         if (entry->type != KVM_IRQ_ROUTING_MSI)
 363                                 continue;
 364                         dest_id = (entry->msi.address_lo >> 12) & 0xff;
 365                         dest_mode = (entry->msi.address_lo >> 2) & 0x1;
 366                         level = entry->msi.data & MSI_DATA_TRIGGER_LEVEL;
 367                         if (level && kvm_apic_match_dest(vcpu, NULL, 0,
 368                                                 dest_id, dest_mode)) {
 369                                 u32 vector = entry->msi.data & 0xff;
 370
 371                                 __set_bit(vector,
 372                                           (unsigned long *) eoi_exit_bitmap);
 373                         }
 374                 }
 375         }
 376         srcu_read_unlock(&kvm->irq_srcu, idx);
 377 }