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 bool kvm_irq_has_notifier(struct kvm *kvm, unsigned irqchip, unsigned pin) 35 { 36 struct kvm_irq_ack_notifier *kian; 37 int gsi, idx; 38 39 idx = srcu_read_lock(&kvm->irq_srcu); 40 gsi = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu)->chip[irqchip][pin]; 41 if (gsi != -1) 42 hlist_for_each_entry_rcu(kian, &kvm->irq_ack_notifier_list, 43 link) 44 if (kian->gsi == gsi) { 45 srcu_read_unlock(&kvm->irq_srcu, idx); 46 return true; 47 } 48 49 srcu_read_unlock(&kvm->irq_srcu, idx); 50 51 return false; 52 } 53 EXPORT_SYMBOL_GPL(kvm_irq_has_notifier); 54 55 void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin) 56 { 57 struct kvm_irq_ack_notifier *kian; 58 int gsi, idx; 59 60 trace_kvm_ack_irq(irqchip, pin); 61 62 idx = srcu_read_lock(&kvm->irq_srcu); 63 gsi = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu)->chip[irqchip][pin]; 64 if (gsi != -1) 65 hlist_for_each_entry_rcu(kian, &kvm->irq_ack_notifier_list, 66 link) 67 if (kian->gsi == gsi) 68 kian->irq_acked(kian); 69 srcu_read_unlock(&kvm->irq_srcu, idx); 70 } 71 72 void kvm_register_irq_ack_notifier(struct kvm *kvm, 73 struct kvm_irq_ack_notifier *kian) 74 { 75 mutex_lock(&kvm->irq_lock); 76 hlist_add_head_rcu(&kian->link, &kvm->irq_ack_notifier_list); 77 mutex_unlock(&kvm->irq_lock); 78 #ifdef __KVM_HAVE_IOAPIC 79 kvm_vcpu_request_scan_ioapic(kvm); 80 #endif 81 } 82 83 void kvm_unregister_irq_ack_notifier(struct kvm *kvm, 84 struct kvm_irq_ack_notifier *kian) 85 { 86 mutex_lock(&kvm->irq_lock); 87 hlist_del_init_rcu(&kian->link); 88 mutex_unlock(&kvm->irq_lock); 89 synchronize_srcu(&kvm->irq_srcu); 90 #ifdef __KVM_HAVE_IOAPIC 91 kvm_vcpu_request_scan_ioapic(kvm); 92 #endif 93 } 94 95 int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi) 96 { 97 struct kvm_kernel_irq_routing_entry route; 98 99 if (!irqchip_in_kernel(kvm) || msi->flags != 0) 100 return -EINVAL; 101 102 route.msi.address_lo = msi->address_lo; 103 route.msi.address_hi = msi->address_hi; 104 route.msi.data = msi->data; 105 106 return kvm_set_msi(&route, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, 1, false); 107 } 108 109 /* 110 * Return value: 111 * < 0 Interrupt was ignored (masked or not delivered for other reasons) 112 * = 0 Interrupt was coalesced (previous irq is still pending) 113 * > 0 Number of CPUs interrupt was delivered to 114 */ 115 int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level, 116 bool line_status) 117 { 118 struct kvm_kernel_irq_routing_entry *e, irq_set[KVM_NR_IRQCHIPS]; 119 int ret = -1, i = 0, idx; 120 struct kvm_irq_routing_table *irq_rt; 121 122 trace_kvm_set_irq(irq, level, irq_source_id); 123 124 /* Not possible to detect if the guest uses the PIC or the 125 * IOAPIC. So set the bit in both. The guest will ignore 126 * writes to the unused one. 127 */ 128 idx = srcu_read_lock(&kvm->irq_srcu); 129 irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu); 130 if (irq < irq_rt->nr_rt_entries) 131 hlist_for_each_entry(e, &irq_rt->map[irq], link) 132 irq_set[i++] = *e; 133 srcu_read_unlock(&kvm->irq_srcu, idx); 134 135 while(i--) { 136 int r; 137 r = irq_set[i].set(&irq_set[i], kvm, irq_source_id, level, 138 line_status); 139 if (r < 0) 140 continue; 141 142 ret = r + ((ret < 0) ? 0 : ret); 143 } 144 145 return ret; 146 } 147 148 void kvm_free_irq_routing(struct kvm *kvm) 149 { 150 /* Called only during vm destruction. Nobody can use the pointer 151 at this stage */ 152 kfree(kvm->irq_routing); 153 } 154 155 static int setup_routing_entry(struct kvm_irq_routing_table *rt, 156 struct kvm_kernel_irq_routing_entry *e, 157 const struct kvm_irq_routing_entry *ue) 158 { 159 int r = -EINVAL; 160 struct kvm_kernel_irq_routing_entry *ei; 161 162 /* 163 * Do not allow GSI to be mapped to the same irqchip more than once. 164 * Allow only one to one mapping between GSI and MSI. 165 */ 166 hlist_for_each_entry(ei, &rt->map[ue->gsi], link) 167 if (ei->type == KVM_IRQ_ROUTING_MSI || 168 ue->type == KVM_IRQ_ROUTING_MSI || 169 ue->u.irqchip.irqchip == ei->irqchip.irqchip) 170 return r; 171 172 e->gsi = ue->gsi; 173 e->type = ue->type; 174 r = kvm_set_routing_entry(rt, e, ue); 175 if (r) 176 goto out; 177 178 hlist_add_head(&e->link, &rt->map[e->gsi]); 179 r = 0; 180 out: 181 return r; 182 } 183 184 int kvm_set_irq_routing(struct kvm *kvm, 185 const struct kvm_irq_routing_entry *ue, 186 unsigned nr, 187 unsigned flags) 188 { 189 struct kvm_irq_routing_table *new, *old; 190 u32 i, j, nr_rt_entries = 0; 191 int r; 192 193 for (i = 0; i < nr; ++i) { 194 if (ue[i].gsi >= KVM_MAX_IRQ_ROUTES) 195 return -EINVAL; 196 nr_rt_entries = max(nr_rt_entries, ue[i].gsi); 197 } 198 199 nr_rt_entries += 1; 200 201 new = kzalloc(sizeof(*new) + (nr_rt_entries * sizeof(struct hlist_head)) 202 + (nr * sizeof(struct kvm_kernel_irq_routing_entry)), 203 GFP_KERNEL); 204 205 if (!new) 206 return -ENOMEM; 207 208 new->rt_entries = (void *)&new->map[nr_rt_entries]; 209 210 new->nr_rt_entries = nr_rt_entries; 211 for (i = 0; i < KVM_NR_IRQCHIPS; i++) 212 for (j = 0; j < KVM_IRQCHIP_NUM_PINS; j++) 213 new->chip[i][j] = -1; 214 215 for (i = 0; i < nr; ++i) { 216 r = -EINVAL; 217 if (ue->flags) 218 goto out; 219 r = setup_routing_entry(new, &new->rt_entries[i], ue); 220 if (r) 221 goto out; 222 ++ue; 223 } 224 225 mutex_lock(&kvm->irq_lock); 226 old = kvm->irq_routing; 227 kvm_irq_routing_update(kvm, new); 228 mutex_unlock(&kvm->irq_lock); 229 230 synchronize_srcu_expedited(&kvm->irq_srcu); 231 232 new = old; 233 r = 0; 234 235 out: 236 kfree(new); 237 return r; 238 } 239