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  * 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 #ifdef CONFIG_IA64
  30 #include <asm/iosapic.h>
  31 #endif
  32
  33 #include "irq.h"
  34
  35 #include "ioapic.h"
  36
  37 static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
  38                            struct kvm *kvm, int irq_source_id, int level,
  39                            bool line_status)
  40 {
  41 #ifdef CONFIG_X86
  42         struct kvm_pic *pic = pic_irqchip(kvm);
  43         return kvm_pic_set_irq(pic, e->irqchip.pin, irq_source_id, level);
  44 #else
  45         return -1;
  46 #endif
  47 }
  48
  49 static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
  50                               struct kvm *kvm, int irq_source_id, int level,
  51                               bool line_status)
  52 {
  53         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
  54         return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, irq_source_id, level,
  55                                 line_status);
  56 }
  57
  58 inline static bool kvm_is_dm_lowest_prio(struct kvm_lapic_irq *irq)
  59 {
  60 #ifdef CONFIG_IA64
  61         return irq->delivery_mode ==
  62                 (IOSAPIC_LOWEST_PRIORITY << IOSAPIC_DELIVERY_SHIFT);
  63 #else
  64         return irq->delivery_mode == APIC_DM_LOWEST;
  65 #endif
  66 }
  67
  68 int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
  69                 struct kvm_lapic_irq *irq, unsigned long *dest_map)
  70 {
  71         int i, r = -1;
  72         struct kvm_vcpu *vcpu, *lowest = NULL;
  73
  74         if (irq->dest_mode == 0 && irq->dest_id == 0xff &&
  75                         kvm_is_dm_lowest_prio(irq)) {
  76                 printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
  77                 irq->delivery_mode = APIC_DM_FIXED;
  78         }
  79
  80         if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
  81                 return r;
  82
  83         kvm_for_each_vcpu(i, vcpu, kvm) {
  84                 if (!kvm_apic_present(vcpu))
  85                         continue;
  86
  87                 if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
  88                                         irq->dest_id, irq->dest_mode))
  89                         continue;
  90
  91                 if (!kvm_is_dm_lowest_prio(irq)) {
  92                         if (r < 0)
  93                                 r = 0;
  94                         r += kvm_apic_set_irq(vcpu, irq, dest_map);
  95                 } else if (kvm_lapic_enabled(vcpu)) {
  96                         if (!lowest)
  97                                 lowest = vcpu;
  98                         else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
  99                                 lowest = vcpu;
 100                 }
 101         }
 102
 103         if (lowest)
 104                 r = kvm_apic_set_irq(lowest, irq, dest_map);
 105
 106         return r;
 107 }
 108
 109 static inline void kvm_set_msi_irq(struct kvm_kernel_irq_routing_entry *e,
 110                                    struct kvm_lapic_irq *irq)
 111 {
 112         trace_kvm_msi_set_irq(e->msi.address_lo, e->msi.data);
 113
 114         irq->dest_id = (e->msi.address_lo &
 115                         MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
 116         irq->vector = (e->msi.data &
 117                         MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
 118         irq->dest_mode = (1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo;
 119         irq->trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
 120         irq->delivery_mode = e->msi.data & 0x700;
 121         irq->level = 1;
 122         irq->shorthand = 0;
 123         /* TODO Deal with RH bit of MSI message address */
 124 }
 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 static int kvm_set_msi_inatomic(struct kvm_kernel_irq_routing_entry *e,
 141                          struct kvm *kvm)
 142 {
 143         struct kvm_lapic_irq irq;
 144         int r;
 145
 146         kvm_set_msi_irq(e, &irq);
 147
 148         if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
 149                 return r;
 150         else
 151                 return -EWOULDBLOCK;
 152 }
 153
 154 /*
 155  * Deliver an IRQ in an atomic context if we can, or return a failure,
 156  * user can retry in a process context.
 157  * Return value:
 158  *  -EWOULDBLOCK - Can't deliver in atomic context: retry in a process context.
 159  *  Other values - No need to retry.
 160  */
 161 int kvm_set_irq_inatomic(struct kvm *kvm, int irq_source_id, u32 irq, int level)
 162 {
 163         struct kvm_kernel_irq_routing_entry entries[KVM_NR_IRQCHIPS];
 164         struct kvm_kernel_irq_routing_entry *e;
 165         int ret = -EINVAL;
 166         int idx;
 167
 168         trace_kvm_set_irq(irq, level, irq_source_id);
 169
 170         /*
 171          * Injection into either PIC or IOAPIC might need to scan all CPUs,
 172          * which would need to be retried from thread context;  when same GSI
 173          * is connected to both PIC and IOAPIC, we'd have to report a
 174          * partial failure here.
 175          * Since there's no easy way to do this, we only support injecting MSI
 176          * which is limited to 1:1 GSI mapping.
 177          */
 178         idx = srcu_read_lock(&kvm->irq_srcu);
 179         if (kvm_irq_map_gsi(kvm, entries, irq) > 0) {
 180                 e = &entries[0];
 181                 if (likely(e->type == KVM_IRQ_ROUTING_MSI))
 182                         ret = kvm_set_msi_inatomic(e, kvm);
 183                 else
 184                         ret = -EWOULDBLOCK;
 185         }
 186         srcu_read_unlock(&kvm->irq_srcu, idx);
 187         return ret;
 188 }
 189
 190 int kvm_request_irq_source_id(struct kvm *kvm)
 191 {
 192         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
 193         int irq_source_id;
 194
 195         mutex_lock(&kvm->irq_lock);
 196         irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
 197
 198         if (irq_source_id >= BITS_PER_LONG) {
 199                 printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
 200                 irq_source_id = -EFAULT;
 201                 goto unlock;
 202         }
 203
 204         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 205 #ifdef CONFIG_X86
 206         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 207 #endif
 208         set_bit(irq_source_id, bitmap);
 209 unlock:
 210         mutex_unlock(&kvm->irq_lock);
 211
 212         return irq_source_id;
 213 }
 214
 215 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 216 {
 217         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 218 #ifdef CONFIG_X86
 219         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 220 #endif
 221
 222         mutex_lock(&kvm->irq_lock);
 223         if (irq_source_id < 0 ||
 224             irq_source_id >= BITS_PER_LONG) {
 225                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 226                 goto unlock;
 227         }
 228         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 229         if (!irqchip_in_kernel(kvm))
 230                 goto unlock;
 231
 232         kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
 233 #ifdef CONFIG_X86
 234         kvm_pic_clear_all(pic_irqchip(kvm), irq_source_id);
 235 #endif
 236 unlock:
 237         mutex_unlock(&kvm->irq_lock);
 238 }
 239
 240 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 241                                     struct kvm_irq_mask_notifier *kimn)
 242 {
 243         mutex_lock(&kvm->irq_lock);
 244         kimn->irq = irq;
 245         hlist_add_head_rcu(&kimn->link, &kvm->mask_notifier_list);
 246         mutex_unlock(&kvm->irq_lock);
 247 }
 248
 249 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 250                                       struct kvm_irq_mask_notifier *kimn)
 251 {
 252         mutex_lock(&kvm->irq_lock);
 253         hlist_del_rcu(&kimn->link);
 254         mutex_unlock(&kvm->irq_lock);
 255         synchronize_srcu(&kvm->irq_srcu);
 256 }
 257
 258 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
 259                              bool mask)
 260 {
 261         struct kvm_irq_mask_notifier *kimn;
 262         int idx, gsi;
 263
 264         idx = srcu_read_lock(&kvm->irq_srcu);
 265         gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
 266         if (gsi != -1)
 267                 hlist_for_each_entry_rcu(kimn, &kvm->mask_notifier_list, link)
 268                         if (kimn->irq == gsi)
 269                                 kimn->func(kimn, mask);
 270         srcu_read_unlock(&kvm->irq_srcu, idx);
 271 }
 272
 273 int kvm_set_routing_entry(struct kvm_kernel_irq_routing_entry *e,
 274                           const struct kvm_irq_routing_entry *ue)
 275 {
 276         int r = -EINVAL;
 277         int delta;
 278         unsigned max_pin;
 279
 280         switch (ue->type) {
 281         case KVM_IRQ_ROUTING_IRQCHIP:
 282                 delta = 0;
 283                 switch (ue->u.irqchip.irqchip) {
 284                 case KVM_IRQCHIP_PIC_MASTER:
 285                         e->set = kvm_set_pic_irq;
 286                         max_pin = PIC_NUM_PINS;
 287                         break;
 288                 case KVM_IRQCHIP_PIC_SLAVE:
 289                         e->set = kvm_set_pic_irq;
 290                         max_pin = PIC_NUM_PINS;
 291                         delta = 8;
 292                         break;
 293                 case KVM_IRQCHIP_IOAPIC:
 294                         max_pin = KVM_IOAPIC_NUM_PINS;
 295                         e->set = kvm_set_ioapic_irq;
 296                         break;
 297                 default:
 298                         goto out;
 299                 }
 300                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 301                 e->irqchip.pin = ue->u.irqchip.pin + delta;
 302                 if (e->irqchip.pin >= max_pin)
 303                         goto out;
 304                 break;
 305         case KVM_IRQ_ROUTING_MSI:
 306                 e->set = kvm_set_msi;
 307                 e->msi.address_lo = ue->u.msi.address_lo;
 308                 e->msi.address_hi = ue->u.msi.address_hi;
 309                 e->msi.data = ue->u.msi.data;
 310                 break;
 311         default:
 312                 goto out;
 313         }
 314
 315         r = 0;
 316 out:
 317         return r;
 318 }
 319
 320 #define IOAPIC_ROUTING_ENTRY(irq) \
 321         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 322           .u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
 323 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 324
 325 #ifdef CONFIG_X86
 326 #  define PIC_ROUTING_ENTRY(irq) \
 327         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 328           .u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
 329 #  define ROUTING_ENTRY2(irq) \
 330         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 331 #else
 332 #  define ROUTING_ENTRY2(irq) \
 333         IOAPIC_ROUTING_ENTRY(irq)
 334 #endif
 335
 336 static const struct kvm_irq_routing_entry default_routing[] = {
 337         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 338         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 339         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 340         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 341         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 342         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 343         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 344         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 345         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 346         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 347         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 348         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 349 #ifdef CONFIG_IA64
 350         ROUTING_ENTRY1(24), ROUTING_ENTRY1(25),
 351         ROUTING_ENTRY1(26), ROUTING_ENTRY1(27),
 352         ROUTING_ENTRY1(28), ROUTING_ENTRY1(29),
 353         ROUTING_ENTRY1(30), ROUTING_ENTRY1(31),
 354         ROUTING_ENTRY1(32), ROUTING_ENTRY1(33),
 355         ROUTING_ENTRY1(34), ROUTING_ENTRY1(35),
 356         ROUTING_ENTRY1(36), ROUTING_ENTRY1(37),
 357         ROUTING_ENTRY1(38), ROUTING_ENTRY1(39),
 358         ROUTING_ENTRY1(40), ROUTING_ENTRY1(41),
 359         ROUTING_ENTRY1(42), ROUTING_ENTRY1(43),
 360         ROUTING_ENTRY1(44), ROUTING_ENTRY1(45),
 361         ROUTING_ENTRY1(46), ROUTING_ENTRY1(47),
 362 #endif
 363 };
 364
 365 int kvm_setup_default_irq_routing(struct kvm *kvm)
 366 {
 367         return kvm_set_irq_routing(kvm, default_routing,
 368                                    ARRAY_SIZE(default_routing), 0);
 369 }