264 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * irqchip.c: Common API for in kernel interrupt controllers4 * Copyright (c) 2007, Intel Corporation.5 * Copyright 2010 Red Hat, Inc. and/or its affiliates.6 * Copyright (c) 2013, Alexander Graf <agraf@suse.de>7 *8 * This file is derived from virt/kvm/irq_comm.c.9 *10 * Authors:11 * Yaozu (Eddie) Dong <Eddie.dong@intel.com>12 * Alexander Graf <agraf@suse.de>13 */14 15#include <linux/kvm_host.h>16#include <linux/slab.h>17#include <linux/srcu.h>18#include <linux/export.h>19#include <trace/events/kvm.h>20 21int kvm_irq_map_gsi(struct kvm *kvm,22 struct kvm_kernel_irq_routing_entry *entries, int gsi)23{24 struct kvm_irq_routing_table *irq_rt;25 struct kvm_kernel_irq_routing_entry *e;26 int n = 0;27 28 irq_rt = srcu_dereference_check(kvm->irq_routing, &kvm->irq_srcu,29 lockdep_is_held(&kvm->irq_lock));30 if (irq_rt && gsi < irq_rt->nr_rt_entries) {31 hlist_for_each_entry(e, &irq_rt->map[gsi], link) {32 entries[n] = *e;33 ++n;34 }35 }36 37 return n;38}39 40int kvm_irq_map_chip_pin(struct kvm *kvm, unsigned irqchip, unsigned pin)41{42 struct kvm_irq_routing_table *irq_rt;43 44 irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);45 return irq_rt->chip[irqchip][pin];46}47 48int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi)49{50 struct kvm_kernel_irq_routing_entry route;51 52 if (!kvm_arch_irqchip_in_kernel(kvm) || (msi->flags & ~KVM_MSI_VALID_DEVID))53 return -EINVAL;54 55 route.msi.address_lo = msi->address_lo;56 route.msi.address_hi = msi->address_hi;57 route.msi.data = msi->data;58 route.msi.flags = msi->flags;59 route.msi.devid = msi->devid;60 61 return kvm_set_msi(&route, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, 1, false);62}63 64/*65 * Return value:66 * < 0 Interrupt was ignored (masked or not delivered for other reasons)67 * = 0 Interrupt was coalesced (previous irq is still pending)68 * > 0 Number of CPUs interrupt was delivered to69 */70int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level,71 bool line_status)72{73 struct kvm_kernel_irq_routing_entry irq_set[KVM_NR_IRQCHIPS];74 int ret = -1, i, idx;75 76 trace_kvm_set_irq(irq, level, irq_source_id);77 78 /* Not possible to detect if the guest uses the PIC or the79 * IOAPIC. So set the bit in both. The guest will ignore80 * writes to the unused one.81 */82 idx = srcu_read_lock(&kvm->irq_srcu);83 i = kvm_irq_map_gsi(kvm, irq_set, irq);84 srcu_read_unlock(&kvm->irq_srcu, idx);85 86 while (i--) {87 int r;88 r = irq_set[i].set(&irq_set[i], kvm, irq_source_id, level,89 line_status);90 if (r < 0)91 continue;92 93 ret = r + ((ret < 0) ? 0 : ret);94 }95 96 return ret;97}98 99static void free_irq_routing_table(struct kvm_irq_routing_table *rt)100{101 int i;102 103 if (!rt)104 return;105 106 for (i = 0; i < rt->nr_rt_entries; ++i) {107 struct kvm_kernel_irq_routing_entry *e;108 struct hlist_node *n;109 110 hlist_for_each_entry_safe(e, n, &rt->map[i], link) {111 hlist_del(&e->link);112 kfree(e);113 }114 }115 116 kfree(rt);117}118 119void kvm_free_irq_routing(struct kvm *kvm)120{121 /* Called only during vm destruction. Nobody can use the pointer122 at this stage */123 struct kvm_irq_routing_table *rt = rcu_access_pointer(kvm->irq_routing);124 free_irq_routing_table(rt);125}126 127static int setup_routing_entry(struct kvm *kvm,128 struct kvm_irq_routing_table *rt,129 struct kvm_kernel_irq_routing_entry *e,130 const struct kvm_irq_routing_entry *ue)131{132 struct kvm_kernel_irq_routing_entry *ei;133 int r;134 u32 gsi = array_index_nospec(ue->gsi, KVM_MAX_IRQ_ROUTES);135 136 /*137 * Do not allow GSI to be mapped to the same irqchip more than once.138 * Allow only one to one mapping between GSI and non-irqchip routing.139 */140 hlist_for_each_entry(ei, &rt->map[gsi], link)141 if (ei->type != KVM_IRQ_ROUTING_IRQCHIP ||142 ue->type != KVM_IRQ_ROUTING_IRQCHIP ||143 ue->u.irqchip.irqchip == ei->irqchip.irqchip)144 return -EINVAL;145 146 e->gsi = gsi;147 e->type = ue->type;148 r = kvm_set_routing_entry(kvm, e, ue);149 if (r)150 return r;151 if (e->type == KVM_IRQ_ROUTING_IRQCHIP)152 rt->chip[e->irqchip.irqchip][e->irqchip.pin] = e->gsi;153 154 hlist_add_head(&e->link, &rt->map[e->gsi]);155 156 return 0;157}158 159void __attribute__((weak)) kvm_arch_irq_routing_update(struct kvm *kvm)160{161}162 163bool __weak kvm_arch_can_set_irq_routing(struct kvm *kvm)164{165 return true;166}167 168int kvm_set_irq_routing(struct kvm *kvm,169 const struct kvm_irq_routing_entry *ue,170 unsigned nr,171 unsigned flags)172{173 struct kvm_irq_routing_table *new, *old;174 struct kvm_kernel_irq_routing_entry *e;175 u32 i, j, nr_rt_entries = 0;176 int r;177 178 for (i = 0; i < nr; ++i) {179 if (ue[i].gsi >= KVM_MAX_IRQ_ROUTES)180 return -EINVAL;181 nr_rt_entries = max(nr_rt_entries, ue[i].gsi);182 }183 184 nr_rt_entries += 1;185 186 new = kzalloc(struct_size(new, map, nr_rt_entries), GFP_KERNEL_ACCOUNT);187 if (!new)188 return -ENOMEM;189 190 new->nr_rt_entries = nr_rt_entries;191 for (i = 0; i < KVM_NR_IRQCHIPS; i++)192 for (j = 0; j < KVM_IRQCHIP_NUM_PINS; j++)193 new->chip[i][j] = -1;194 195 for (i = 0; i < nr; ++i) {196 r = -ENOMEM;197 e = kzalloc(sizeof(*e), GFP_KERNEL_ACCOUNT);198 if (!e)199 goto out;200 201 r = -EINVAL;202 switch (ue->type) {203 case KVM_IRQ_ROUTING_MSI:204 if (ue->flags & ~KVM_MSI_VALID_DEVID)205 goto free_entry;206 break;207 default:208 if (ue->flags)209 goto free_entry;210 break;211 }212 r = setup_routing_entry(kvm, new, e, ue);213 if (r)214 goto free_entry;215 ++ue;216 }217 218 mutex_lock(&kvm->irq_lock);219 old = rcu_dereference_protected(kvm->irq_routing, 1);220 rcu_assign_pointer(kvm->irq_routing, new);221 kvm_irq_routing_update(kvm);222 kvm_arch_irq_routing_update(kvm);223 mutex_unlock(&kvm->irq_lock);224 225 kvm_arch_post_irq_routing_update(kvm);226 227 synchronize_srcu_expedited(&kvm->irq_srcu);228 229 new = old;230 r = 0;231 goto out;232 233free_entry:234 kfree(e);235out:236 free_irq_routing_table(new);237 238 return r;239}240 241/*242 * Allocate empty IRQ routing by default so that additional setup isn't needed243 * when userspace-driven IRQ routing is activated, and so that kvm->irq_routing244 * is guaranteed to be non-NULL.245 */246int kvm_init_irq_routing(struct kvm *kvm)247{248 struct kvm_irq_routing_table *new;249 int chip_size;250 251 new = kzalloc(struct_size(new, map, 1), GFP_KERNEL_ACCOUNT);252 if (!new)253 return -ENOMEM;254 255 new->nr_rt_entries = 1;256 257 chip_size = sizeof(int) * KVM_NR_IRQCHIPS * KVM_IRQCHIP_NUM_PINS;258 memset(new->chip, -1, chip_size);259 260 RCU_INIT_POINTER(kvm->irq_routing, new);261 262 return 0;263}264