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 static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
  35                            struct kvm *kvm, int irq_source_id, int level,
  36                            bool line_status)
  37 {
  38         struct kvm_pic *pic = pic_irqchip(kvm);
  39         return kvm_pic_set_irq(pic, e->irqchip.pin, irq_source_id, level);
  40 }
  41
  42 static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
  43                               struct kvm *kvm, int irq_source_id, int level,
  44                               bool line_status)
  45 {
  46         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
  47         return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, irq_source_id, level,
  48                                 line_status);
  49 }
  50
  51 inline static bool kvm_is_dm_lowest_prio(struct kvm_lapic_irq *irq)
  52 {
  53         return irq->delivery_mode == APIC_DM_LOWEST;
  54 }
  55
  56 int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
  57                 struct kvm_lapic_irq *irq, unsigned long *dest_map)
  58 {
  59         int i, r = -1;
  60         struct kvm_vcpu *vcpu, *lowest = NULL;
  61
  62         if (irq->dest_mode == 0 && irq->dest_id == 0xff &&
  63                         kvm_is_dm_lowest_prio(irq)) {
  64                 printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
  65                 irq->delivery_mode = APIC_DM_FIXED;
  66         }
  67
  68         if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
  69                 return r;
  70
  71         kvm_for_each_vcpu(i, vcpu, kvm) {
  72                 if (!kvm_apic_present(vcpu))
  73                         continue;
  74
  75                 if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
  76                                         irq->dest_id, irq->dest_mode))
  77                         continue;
  78
  79                 if (!kvm_is_dm_lowest_prio(irq)) {
  80                         if (r < 0)
  81                                 r = 0;
  82                         r += kvm_apic_set_irq(vcpu, irq, dest_map);
  83                 } else if (kvm_lapic_enabled(vcpu)) {
  84                         if (!lowest)
  85                                 lowest = vcpu;
  86                         else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
  87                                 lowest = vcpu;
  88                 }
  89         }
  90
  91         if (lowest)
  92                 r = kvm_apic_set_irq(lowest, irq, dest_map);
  93
  94         return r;
  95 }
  96
  97 static inline void kvm_set_msi_irq(struct kvm_kernel_irq_routing_entry *e,
  98                                    struct kvm_lapic_irq *irq)
  99 {
 100         trace_kvm_msi_set_irq(e->msi.address_lo, e->msi.data);
 101
 102         irq->dest_id = (e->msi.address_lo &
 103                         MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
 104         irq->vector = (e->msi.data &
 105                         MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
 106         irq->dest_mode = (1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo;
 107         irq->trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
 108         irq->delivery_mode = e->msi.data & 0x700;
 109         irq->level = 1;
 110         irq->shorthand = 0;
 111         /* TODO Deal with RH bit of MSI message address */
 112 }
 113
 114 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
 115                 struct kvm *kvm, int irq_source_id, int level, bool line_status)
 116 {
 117         struct kvm_lapic_irq irq;
 118
 119         if (!level)
 120                 return -1;
 121
 122         kvm_set_msi_irq(e, &irq);
 123
 124         return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
 125 }
 126
 127
 128 static int kvm_set_msi_inatomic(struct kvm_kernel_irq_routing_entry *e,
 129                          struct kvm *kvm)
 130 {
 131         struct kvm_lapic_irq irq;
 132         int r;
 133
 134         kvm_set_msi_irq(e, &irq);
 135
 136         if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
 137                 return r;
 138         else
 139                 return -EWOULDBLOCK;
 140 }
 141
 142 /*
 143  * Deliver an IRQ in an atomic context if we can, or return a failure,
 144  * user can retry in a process context.
 145  * Return value:
 146  *  -EWOULDBLOCK - Can't deliver in atomic context: retry in a process context.
 147  *  Other values - No need to retry.
 148  */
 149 int kvm_set_irq_inatomic(struct kvm *kvm, int irq_source_id, u32 irq, int level)
 150 {
 151         struct kvm_kernel_irq_routing_entry entries[KVM_NR_IRQCHIPS];
 152         struct kvm_kernel_irq_routing_entry *e;
 153         int ret = -EINVAL;
 154         int idx;
 155
 156         trace_kvm_set_irq(irq, level, irq_source_id);
 157
 158         /*
 159          * Injection into either PIC or IOAPIC might need to scan all CPUs,
 160          * which would need to be retried from thread context;  when same GSI
 161          * is connected to both PIC and IOAPIC, we'd have to report a
 162          * partial failure here.
 163          * Since there's no easy way to do this, we only support injecting MSI
 164          * which is limited to 1:1 GSI mapping.
 165          */
 166         idx = srcu_read_lock(&kvm->irq_srcu);
 167         if (kvm_irq_map_gsi(kvm, entries, irq) > 0) {
 168                 e = &entries[0];
 169                 if (likely(e->type == KVM_IRQ_ROUTING_MSI))
 170                         ret = kvm_set_msi_inatomic(e, kvm);
 171                 else
 172                         ret = -EWOULDBLOCK;
 173         }
 174         srcu_read_unlock(&kvm->irq_srcu, idx);
 175         return ret;
 176 }
 177
 178 int kvm_request_irq_source_id(struct kvm *kvm)
 179 {
 180         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
 181         int irq_source_id;
 182
 183         mutex_lock(&kvm->irq_lock);
 184         irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
 185
 186         if (irq_source_id >= BITS_PER_LONG) {
 187                 printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
 188                 irq_source_id = -EFAULT;
 189                 goto unlock;
 190         }
 191
 192         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 193         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 194         set_bit(irq_source_id, bitmap);
 195 unlock:
 196         mutex_unlock(&kvm->irq_lock);
 197
 198         return irq_source_id;
 199 }
 200
 201 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 202 {
 203         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 204         ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 205
 206         mutex_lock(&kvm->irq_lock);
 207         if (irq_source_id < 0 ||
 208             irq_source_id >= BITS_PER_LONG) {
 209                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 210                 goto unlock;
 211         }
 212         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 213         if (!irqchip_in_kernel(kvm))
 214                 goto unlock;
 215
 216         kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
 217         kvm_pic_clear_all(pic_irqchip(kvm), irq_source_id);
 218 unlock:
 219         mutex_unlock(&kvm->irq_lock);
 220 }
 221
 222 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 223                                     struct kvm_irq_mask_notifier *kimn)
 224 {
 225         mutex_lock(&kvm->irq_lock);
 226         kimn->irq = irq;
 227         hlist_add_head_rcu(&kimn->link, &kvm->arch.mask_notifier_list);
 228         mutex_unlock(&kvm->irq_lock);
 229 }
 230
 231 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 232                                       struct kvm_irq_mask_notifier *kimn)
 233 {
 234         mutex_lock(&kvm->irq_lock);
 235         hlist_del_rcu(&kimn->link);
 236         mutex_unlock(&kvm->irq_lock);
 237         synchronize_srcu(&kvm->irq_srcu);
 238 }
 239
 240 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
 241                              bool mask)
 242 {
 243         struct kvm_irq_mask_notifier *kimn;
 244         int idx, gsi;
 245
 246         idx = srcu_read_lock(&kvm->irq_srcu);
 247         gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
 248         if (gsi != -1)
 249                 hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
 250                         if (kimn->irq == gsi)
 251                                 kimn->func(kimn, mask);
 252         srcu_read_unlock(&kvm->irq_srcu, idx);
 253 }
 254
 255 int kvm_set_routing_entry(struct kvm_kernel_irq_routing_entry *e,
 256                           const struct kvm_irq_routing_entry *ue)
 257 {
 258         int r = -EINVAL;
 259         int delta;
 260         unsigned max_pin;
 261
 262         switch (ue->type) {
 263         case KVM_IRQ_ROUTING_IRQCHIP:
 264                 delta = 0;
 265                 switch (ue->u.irqchip.irqchip) {
 266                 case KVM_IRQCHIP_PIC_MASTER:
 267                         e->set = kvm_set_pic_irq;
 268                         max_pin = PIC_NUM_PINS;
 269                         break;
 270                 case KVM_IRQCHIP_PIC_SLAVE:
 271                         e->set = kvm_set_pic_irq;
 272                         max_pin = PIC_NUM_PINS;
 273                         delta = 8;
 274                         break;
 275                 case KVM_IRQCHIP_IOAPIC:
 276                         max_pin = KVM_IOAPIC_NUM_PINS;
 277                         e->set = kvm_set_ioapic_irq;
 278                         break;
 279                 default:
 280                         goto out;
 281                 }
 282                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 283                 e->irqchip.pin = ue->u.irqchip.pin + delta;
 284                 if (e->irqchip.pin >= max_pin)
 285                         goto out;
 286                 break;
 287         case KVM_IRQ_ROUTING_MSI:
 288                 e->set = kvm_set_msi;
 289                 e->msi.address_lo = ue->u.msi.address_lo;
 290                 e->msi.address_hi = ue->u.msi.address_hi;
 291                 e->msi.data = ue->u.msi.data;
 292                 break;
 293         default:
 294                 goto out;
 295         }
 296
 297         r = 0;
 298 out:
 299         return r;
 300 }
 301
 302 #define IOAPIC_ROUTING_ENTRY(irq) \
 303         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 304           .u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
 305 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 306
 307 #define PIC_ROUTING_ENTRY(irq) \
 308         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 309           .u.irqchip = { .irqchip = SELECT_PIC(irq), .pin = (irq) % 8 } }
 310 #define ROUTING_ENTRY2(irq) \
 311         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 312
 313 static const struct kvm_irq_routing_entry default_routing[] = {
 314         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 315         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 316         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 317         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 318         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 319         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 320         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 321         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 322         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 323         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 324         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 325         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 326 };
 327
 328 int kvm_setup_default_irq_routing(struct kvm *kvm)
 329 {
 330         return kvm_set_irq_routing(kvm, default_routing,
 331                                    ARRAY_SIZE(default_routing), 0);
 332 }