1 /* 2 * irqchip.c: Common API for in kernel interrupt controllers 3 * Copyright (c) 2007, Intel Corporation. 4 * Copyright 2010 Red Hat, Inc. and/or its affiliates. 5 * Copyright (c) 2013, Alexander Graf <agraf@suse.de> 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms and conditions of the GNU General Public License, 9 * version 2, as published by the Free Software Foundation. 10 * 11 * This program is distributed in the hope it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 14 * more details. 15 * 16 * You should have received a copy of the GNU General Public License along with 17 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple 18 * Place - Suite 330, Boston, MA 02111-1307 USA. 19 * 20 * This file is derived from virt/kvm/irq_comm.c. 21 * 22 * Authors: 23 * Yaozu (Eddie) Dong <Eddie.dong@intel.com> 24 * Alexander Graf <agraf@suse.de> 25 */ 26 27 #include <linux/kvm_host.h> 28 #include <linux/slab.h> 29 #include <linux/srcu.h> 30 #include <linux/export.h> 31 #include <trace/events/kvm.h> 32 #include "irq.h" 33 34 int kvm_irq_map_gsi(struct kvm *kvm, 35 struct kvm_kernel_irq_routing_entry *entries, int gsi) 36 { 37 struct kvm_irq_routing_table *irq_rt; 38 struct kvm_kernel_irq_routing_entry *e; 39 int n = 0; 40 41 irq_rt = srcu_dereference_check(kvm->irq_routing, &kvm->irq_srcu, 42 lockdep_is_held(&kvm->irq_lock)); 43 if (irq_rt && gsi < irq_rt->nr_rt_entries) { 44 hlist_for_each_entry(e, &irq_rt->map[gsi], link) { 45 entries[n] = *e; 46 ++n; 47 } 48 } 49 50 return n; 51 } 52 53 int kvm_irq_map_chip_pin(struct kvm *kvm, unsigned irqchip, unsigned pin) 54 { 55 struct kvm_irq_routing_table *irq_rt; 56 57 irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu); 58 return irq_rt->chip[irqchip][pin]; 59 } 60 61 int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi) 62 { 63 struct kvm_kernel_irq_routing_entry route; 64 65 if (!irqchip_in_kernel(kvm) || (msi->flags & ~KVM_MSI_VALID_DEVID)) 66 return -EINVAL; 67 68 route.msi.address_lo = msi->address_lo; 69 route.msi.address_hi = msi->address_hi; 70 route.msi.data = msi->data; 71 route.msi.flags = msi->flags; 72 route.msi.devid = msi->devid; 73 74 return kvm_set_msi(&route, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, 1, false); 75 } 76 77 /* 78 * Return value: 79 * < 0 Interrupt was ignored (masked or not delivered for other reasons) 80 * = 0 Interrupt was coalesced (previous irq is still pending) 81 * > 0 Number of CPUs interrupt was delivered to 82 */ 83 int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level, 84 bool line_status) 85 { 86 struct kvm_kernel_irq_routing_entry irq_set[KVM_NR_IRQCHIPS]; 87 int ret = -1, i, idx; 88 89 trace_kvm_set_irq(irq, level, irq_source_id); 90 91 /* Not possible to detect if the guest uses the PIC or the 92 * IOAPIC. So set the bit in both. The guest will ignore 93 * writes to the unused one. 94 */ 95 idx = srcu_read_lock(&kvm->irq_srcu); 96 i = kvm_irq_map_gsi(kvm, irq_set, irq); 97 srcu_read_unlock(&kvm->irq_srcu, idx); 98 99 while (i--) { 100 int r; 101 r = irq_set[i].set(&irq_set[i], kvm, irq_source_id, level, 102 line_status); 103 if (r < 0) 104 continue; 105 106 ret = r + ((ret < 0) ? 0 : ret); 107 } 108 109 return ret; 110 } 111 112 static void free_irq_routing_table(struct kvm_irq_routing_table *rt) 113 { 114 int i; 115 116 if (!rt) 117 return; 118 119 for (i = 0; i < rt->nr_rt_entries; ++i) { 120 struct kvm_kernel_irq_routing_entry *e; 121 struct hlist_node *n; 122 123 hlist_for_each_entry_safe(e, n, &rt->map[i], link) { 124 hlist_del(&e->link); 125 kfree(e); 126 } 127 } 128 129 kfree(rt); 130 } 131 132 void kvm_free_irq_routing(struct kvm *kvm) 133 { 134 /* Called only during vm destruction. Nobody can use the pointer 135 at this stage */ 136 struct kvm_irq_routing_table *rt = rcu_access_pointer(kvm->irq_routing); 137 free_irq_routing_table(rt); 138 } 139 140 static int setup_routing_entry(struct kvm *kvm, 141 struct kvm_irq_routing_table *rt, 142 struct kvm_kernel_irq_routing_entry *e, 143 const struct kvm_irq_routing_entry *ue) 144 { 145 struct kvm_kernel_irq_routing_entry *ei; 146 int r; 147 148 /* 149 * Do not allow GSI to be mapped to the same irqchip more than once. 150 * Allow only one to one mapping between GSI and non-irqchip routing. 151 */ 152 hlist_for_each_entry(ei, &rt->map[ue->gsi], link) 153 if (ei->type != KVM_IRQ_ROUTING_IRQCHIP || 154 ue->type != KVM_IRQ_ROUTING_IRQCHIP || 155 ue->u.irqchip.irqchip == ei->irqchip.irqchip) 156 return -EINVAL; 157 158 e->gsi = ue->gsi; 159 e->type = ue->type; 160 r = kvm_set_routing_entry(kvm, e, ue); 161 if (r) 162 return r; 163 if (e->type == KVM_IRQ_ROUTING_IRQCHIP) 164 rt->chip[e->irqchip.irqchip][e->irqchip.pin] = e->gsi; 165 166 hlist_add_head(&e->link, &rt->map[e->gsi]); 167 168 return 0; 169 } 170 171 void __attribute__((weak)) kvm_arch_irq_routing_update(struct kvm *kvm) 172 { 173 } 174 175 bool __weak kvm_arch_can_set_irq_routing(struct kvm *kvm) 176 { 177 return true; 178 } 179 180 int kvm_set_irq_routing(struct kvm *kvm, 181 const struct kvm_irq_routing_entry *ue, 182 unsigned nr, 183 unsigned flags) 184 { 185 struct kvm_irq_routing_table *new, *old; 186 struct kvm_kernel_irq_routing_entry *e; 187 u32 i, j, nr_rt_entries = 0; 188 int r; 189 190 for (i = 0; i < nr; ++i) { 191 if (ue[i].gsi >= KVM_MAX_IRQ_ROUTES) 192 return -EINVAL; 193 nr_rt_entries = max(nr_rt_entries, ue[i].gsi); 194 } 195 196 nr_rt_entries += 1; 197 198 new = kzalloc(sizeof(*new) + (nr_rt_entries * sizeof(struct hlist_head)), 199 GFP_KERNEL); 200 201 if (!new) 202 return -ENOMEM; 203 204 new->nr_rt_entries = nr_rt_entries; 205 for (i = 0; i < KVM_NR_IRQCHIPS; i++) 206 for (j = 0; j < KVM_IRQCHIP_NUM_PINS; j++) 207 new->chip[i][j] = -1; 208 209 for (i = 0; i < nr; ++i) { 210 r = -ENOMEM; 211 e = kzalloc(sizeof(*e), GFP_KERNEL); 212 if (!e) 213 goto out; 214 215 r = -EINVAL; 216 switch (ue->type) { 217 case KVM_IRQ_ROUTING_MSI: 218 if (ue->flags & ~KVM_MSI_VALID_DEVID) 219 goto free_entry; 220 break; 221 default: 222 if (ue->flags) 223 goto free_entry; 224 break; 225 } 226 r = setup_routing_entry(kvm, new, e, ue); 227 if (r) 228 goto free_entry; 229 ++ue; 230 } 231 232 mutex_lock(&kvm->irq_lock); 233 old = kvm->irq_routing; 234 rcu_assign_pointer(kvm->irq_routing, new); 235 kvm_irq_routing_update(kvm); 236 kvm_arch_irq_routing_update(kvm); 237 mutex_unlock(&kvm->irq_lock); 238 239 kvm_arch_post_irq_routing_update(kvm); 240 241 synchronize_srcu_expedited(&kvm->irq_srcu); 242 243 new = old; 244 r = 0; 245 goto out; 246 247 free_entry: 248 kfree(e); 249 out: 250 free_irq_routing_table(new); 251 252 return r; 253 } 254