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
  42         /*
  43          * XXX: rejecting pic routes when pic isn't in use would be better,
  44          * but the default routing table is installed while kvm->arch.vpic is
  45          * NULL and KVM_CREATE_IRQCHIP can race with KVM_IRQ_LINE.
  46          */
  47         if (!pic)
  48                 return -1;
  49
  50         return kvm_pic_set_irq(pic, e->irqchip.pin, irq_source_id, level);
  51 }
  52
  53 static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
  54                               struct kvm *kvm, int irq_source_id, int level,
  55                               bool line_status)
  56 {
  57         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
  58
  59         if (!ioapic)
  60                 return -1;
  61
  62         return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, irq_source_id, level,
  63                                 line_status);
  64 }
  65
  66 int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
  67                 struct kvm_lapic_irq *irq, unsigned long *dest_map)
  68 {
  69         int i, r = -1;
  70         struct kvm_vcpu *vcpu, *lowest = NULL;
  71
  72         if (irq->dest_mode == 0 && irq->dest_id == 0xff &&
  73                         kvm_lowest_prio_delivery(irq)) {
  74                 printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
  75                 irq->delivery_mode = APIC_DM_FIXED;
  76         }
  77
  78         if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
  79                 return r;
  80
  81         kvm_for_each_vcpu(i, vcpu, kvm) {
  82                 if (!kvm_apic_present(vcpu))
  83                         continue;
  84
  85                 if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
  86                                         irq->dest_id, irq->dest_mode))
  87                         continue;
  88
  89                 if (!kvm_lowest_prio_delivery(irq)) {
  90                         if (r < 0)
  91                                 r = 0;
  92                         r += kvm_apic_set_irq(vcpu, irq, dest_map);
  93                 } else if (kvm_lapic_enabled(vcpu)) {
  94                         if (!lowest)
  95                                 lowest = vcpu;
  96                         else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
  97                                 lowest = vcpu;
  98                 }
  99         }
 100
 101         if (lowest)
 102                 r = kvm_apic_set_irq(lowest, irq, dest_map);
 103
 104         return r;
 105 }
 106
 107 void kvm_set_msi_irq(struct kvm_kernel_irq_routing_entry *e,
 108                      struct kvm_lapic_irq *irq)
 109 {
 110         trace_kvm_msi_set_irq(e->msi.address_lo, e->msi.data);
 111
 112         irq->dest_id = (e->msi.address_lo &
 113                         MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
 114         irq->vector = (e->msi.data &
 115                         MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
 116         irq->dest_mode = (1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo;
 117         irq->trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
 118         irq->delivery_mode = e->msi.data & 0x700;
 119         irq->msi_redir_hint = ((e->msi.address_lo
 120                 & MSI_ADDR_REDIRECTION_LOWPRI) > 0);
 121         irq->level = 1;
 122         irq->shorthand = 0;
 123 }
 124 EXPORT_SYMBOL_GPL(kvm_set_msi_irq);
 125
 126 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
 127                 struct kvm *kvm, int irq_source_id, int level, bool line_status)
 128 {
 129         struct kvm_lapic_irq irq;
 130
 131         if (!level)
 132                 return -1;
 133
 134         kvm_set_msi_irq(e, &irq);
 135
 136         return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
 137 }
 138
 139
 140 int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
 141                               struct kvm *kvm, int irq_source_id, int level,
 142                               bool line_status)
 143 {
 144         struct kvm_lapic_irq irq;
 145         int r;
 146
 147         if (unlikely(e->type != KVM_IRQ_ROUTING_MSI))
 148                 return -EWOULDBLOCK;
 149
 150         kvm_set_msi_irq(e, &irq);
 151
 152         if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
 153                 return r;
 154         else
 155                 return -EWOULDBLOCK;
 156 }
 157
 158 int kvm_request_irq_source_id(struct kvm *kvm)
 159 {
 160         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
 161         int irq_source_id;
 162
 163         mutex_lock(&kvm->irq_lock);
 164         irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
 165
 166         if (irq_source_id >= BITS_PER_LONG) {
 167                 printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
 168                 irq_source_id = -EFAULT;
 169                 goto unlock;
 170         }
 171
 172         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 173         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 174         set_bit(irq_source_id, bitmap);
 175 unlock:
 176         mutex_unlock(&kvm->irq_lock);
 177
 178         return irq_source_id;
 179 }
 180
 181 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 182 {
 183         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 184         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 185
 186         mutex_lock(&kvm->irq_lock);
 187         if (irq_source_id < 0 ||
 188             irq_source_id >= BITS_PER_LONG) {
 189                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 190                 goto unlock;
 191         }
 192         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 193         if (!ioapic_in_kernel(kvm))
 194                 goto unlock;
 195
 196         kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
 197         kvm_pic_clear_all(pic_irqchip(kvm), irq_source_id);
 198 unlock:
 199         mutex_unlock(&kvm->irq_lock);
 200 }
 201
 202 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 203                                     struct kvm_irq_mask_notifier *kimn)
 204 {
 205         mutex_lock(&kvm->irq_lock);
 206         kimn->irq = irq;
 207         hlist_add_head_rcu(&kimn->link, &kvm->arch.mask_notifier_list);
 208         mutex_unlock(&kvm->irq_lock);
 209 }
 210
 211 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 212                                       struct kvm_irq_mask_notifier *kimn)
 213 {
 214         mutex_lock(&kvm->irq_lock);
 215         hlist_del_rcu(&kimn->link);
 216         mutex_unlock(&kvm->irq_lock);
 217         synchronize_srcu(&kvm->irq_srcu);
 218 }
 219
 220 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
 221                              bool mask)
 222 {
 223         struct kvm_irq_mask_notifier *kimn;
 224         int idx, gsi;
 225
 226         idx = srcu_read_lock(&kvm->irq_srcu);
 227         gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
 228         if (gsi != -1)
 229                 hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
 230                         if (kimn->irq == gsi)
 231                                 kimn->func(kimn, mask);
 232         srcu_read_unlock(&kvm->irq_srcu, idx);
 233 }
 234
 235 int kvm_set_routing_entry(struct kvm_kernel_irq_routing_entry *e,
 236                           const struct kvm_irq_routing_entry *ue)
 237 {
 238         int r = -EINVAL;
 239         int delta;
 240         unsigned max_pin;
 241
 242         switch (ue->type) {
 243         case KVM_IRQ_ROUTING_IRQCHIP:
 244                 delta = 0;
 245                 switch (ue->u.irqchip.irqchip) {
 246                 case KVM_IRQCHIP_PIC_MASTER:
 247                         e->set = kvm_set_pic_irq;
 248                         max_pin = PIC_NUM_PINS;
 249                         break;
 250                 case KVM_IRQCHIP_PIC_SLAVE:
 251                         e->set = kvm_set_pic_irq;
 252                         max_pin = PIC_NUM_PINS;
 253                         delta = 8;
 254                         break;
 255                 case KVM_IRQCHIP_IOAPIC:
 256                         max_pin = KVM_IOAPIC_NUM_PINS;
 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                 if (e->irqchip.pin >= max_pin)
 265                         goto out;
 266                 break;
 267         case KVM_IRQ_ROUTING_MSI:
 268                 e->set = kvm_set_msi;
 269                 e->msi.address_lo = ue->u.msi.address_lo;
 270                 e->msi.address_hi = ue->u.msi.address_hi;
 271                 e->msi.data = ue->u.msi.data;
 272                 break;
 273         default:
 274                 goto out;
 275         }
 276
 277         r = 0;
 278 out:
 279         return r;
 280 }
 281
 282 bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
 283                              struct kvm_vcpu **dest_vcpu)
 284 {
 285         int i, r = 0;
 286         struct kvm_vcpu *vcpu;
 287
 288         if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
 289                 return true;
 290
 291         kvm_for_each_vcpu(i, vcpu, kvm) {
 292                 if (!kvm_apic_present(vcpu))
 293                         continue;
 294
 295                 if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand,
 296                                         irq->dest_id, irq->dest_mode))
 297                         continue;
 298
 299                 if (++r == 2)
 300                         return false;
 301
 302                 *dest_vcpu = vcpu;
 303         }
 304
 305         return r == 1;
 306 }
 307 EXPORT_SYMBOL_GPL(kvm_intr_is_single_vcpu);
 308
 309 #define IOAPIC_ROUTING_ENTRY(irq) \
 310         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 311           .u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
 312 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 313
 314 #define PIC_ROUTING_ENTRY(irq) \
 315         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 316           .u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
 317 #define ROUTING_ENTRY2(irq) \
 318         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 319
 320 static const struct kvm_irq_routing_entry default_routing[] = {
 321         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 322         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 323         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 324         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 325         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 326         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 327         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 328         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 329         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 330         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 331         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 332         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 333 };
 334
 335 int kvm_setup_default_irq_routing(struct kvm *kvm)
 336 {
 337         return kvm_set_irq_routing(kvm, default_routing,
 338                                    ARRAY_SIZE(default_routing), 0);
 339 }
 340
 341 static const struct kvm_irq_routing_entry empty_routing[] = {};
 342
 343 int kvm_setup_empty_irq_routing(struct kvm *kvm)
 344 {
 345         return kvm_set_irq_routing(kvm, empty_routing, 0, 0);
 346 }
 347
 348 void kvm_arch_irq_routing_update(struct kvm *kvm)
 349 {
 350         if (ioapic_in_kernel(kvm) || !irqchip_in_kernel(kvm))
 351                 return;
 352         kvm_make_scan_ioapic_request(kvm);
 353 }
 354
 355 void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap)
 356 {
 357         struct kvm *kvm = vcpu->kvm;
 358         struct kvm_kernel_irq_routing_entry *entry;
 359         struct kvm_irq_routing_table *table;
 360         u32 i, nr_ioapic_pins;
 361         int idx;
 362
 363         /* kvm->irq_routing must be read after clearing
 364          * KVM_SCAN_IOAPIC. */
 365         smp_mb();
 366         idx = srcu_read_lock(&kvm->irq_srcu);
 367         table = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
 368         nr_ioapic_pins = min_t(u32, table->nr_rt_entries,
 369                                kvm->arch.nr_reserved_ioapic_pins);
 370         for (i = 0; i < nr_ioapic_pins; ++i) {
 371                 hlist_for_each_entry(entry, &table->map[i], link) {
 372                         u32 dest_id, dest_mode;
 373                         bool level;
 374
 375                         if (entry->type != KVM_IRQ_ROUTING_MSI)
 376                                 continue;
 377                         dest_id = (entry->msi.address_lo >> 12) & 0xff;
 378                         dest_mode = (entry->msi.address_lo >> 2) & 0x1;
 379                         level = entry->msi.data & MSI_DATA_TRIGGER_LEVEL;
 380                         if (level && kvm_apic_match_dest(vcpu, NULL, 0,
 381                                                 dest_id, dest_mode)) {
 382                                 u32 vector = entry->msi.data & 0xff;
 383
 384                                 __set_bit(vector,
 385                                           (unsigned long *) eoi_exit_bitmap);
 386                         }
 387                 }
 388         }
 389         srcu_read_unlock(&kvm->irq_srcu, idx);
 390 }