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