1 /* 2 * Copyright 2012 Michael Ellerman, IBM Corporation. 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License, version 2, as 6 * published by the Free Software Foundation. 7 */ 8 9 #include <linux/kernel.h> 10 #include <linux/kvm_host.h> 11 #include <linux/kvm.h> 12 #include <linux/err.h> 13 14 #include <linux/uaccess.h> 15 #include <asm/kvm_book3s.h> 16 #include <asm/kvm_ppc.h> 17 #include <asm/hvcall.h> 18 #include <asm/rtas.h> 19 #include <asm/xive.h> 20 21 #ifdef CONFIG_KVM_XICS 22 static void kvm_rtas_set_xive(struct kvm_vcpu *vcpu, struct rtas_args *args) 23 { 24 u32 irq, server, priority; 25 int rc; 26 27 if (be32_to_cpu(args->nargs) != 3 || be32_to_cpu(args->nret) != 1) { 28 rc = -3; 29 goto out; 30 } 31 32 irq = be32_to_cpu(args->args[0]); 33 server = be32_to_cpu(args->args[1]); 34 priority = be32_to_cpu(args->args[2]); 35 36 if (xics_on_xive()) 37 rc = kvmppc_xive_set_xive(vcpu->kvm, irq, server, priority); 38 else 39 rc = kvmppc_xics_set_xive(vcpu->kvm, irq, server, priority); 40 if (rc) 41 rc = -3; 42 out: 43 args->rets[0] = cpu_to_be32(rc); 44 } 45 46 static void kvm_rtas_get_xive(struct kvm_vcpu *vcpu, struct rtas_args *args) 47 { 48 u32 irq, server, priority; 49 int rc; 50 51 if (be32_to_cpu(args->nargs) != 1 || be32_to_cpu(args->nret) != 3) { 52 rc = -3; 53 goto out; 54 } 55 56 irq = be32_to_cpu(args->args[0]); 57 58 server = priority = 0; 59 if (xics_on_xive()) 60 rc = kvmppc_xive_get_xive(vcpu->kvm, irq, &server, &priority); 61 else 62 rc = kvmppc_xics_get_xive(vcpu->kvm, irq, &server, &priority); 63 if (rc) { 64 rc = -3; 65 goto out; 66 } 67 68 args->rets[1] = cpu_to_be32(server); 69 args->rets[2] = cpu_to_be32(priority); 70 out: 71 args->rets[0] = cpu_to_be32(rc); 72 } 73 74 static void kvm_rtas_int_off(struct kvm_vcpu *vcpu, struct rtas_args *args) 75 { 76 u32 irq; 77 int rc; 78 79 if (be32_to_cpu(args->nargs) != 1 || be32_to_cpu(args->nret) != 1) { 80 rc = -3; 81 goto out; 82 } 83 84 irq = be32_to_cpu(args->args[0]); 85 86 if (xics_on_xive()) 87 rc = kvmppc_xive_int_off(vcpu->kvm, irq); 88 else 89 rc = kvmppc_xics_int_off(vcpu->kvm, irq); 90 if (rc) 91 rc = -3; 92 out: 93 args->rets[0] = cpu_to_be32(rc); 94 } 95 96 static void kvm_rtas_int_on(struct kvm_vcpu *vcpu, struct rtas_args *args) 97 { 98 u32 irq; 99 int rc; 100 101 if (be32_to_cpu(args->nargs) != 1 || be32_to_cpu(args->nret) != 1) { 102 rc = -3; 103 goto out; 104 } 105 106 irq = be32_to_cpu(args->args[0]); 107 108 if (xics_on_xive()) 109 rc = kvmppc_xive_int_on(vcpu->kvm, irq); 110 else 111 rc = kvmppc_xics_int_on(vcpu->kvm, irq); 112 if (rc) 113 rc = -3; 114 out: 115 args->rets[0] = cpu_to_be32(rc); 116 } 117 #endif /* CONFIG_KVM_XICS */ 118 119 struct rtas_handler { 120 void (*handler)(struct kvm_vcpu *vcpu, struct rtas_args *args); 121 char *name; 122 }; 123 124 static struct rtas_handler rtas_handlers[] = { 125 #ifdef CONFIG_KVM_XICS 126 { .name = "ibm,set-xive", .handler = kvm_rtas_set_xive }, 127 { .name = "ibm,get-xive", .handler = kvm_rtas_get_xive }, 128 { .name = "ibm,int-off", .handler = kvm_rtas_int_off }, 129 { .name = "ibm,int-on", .handler = kvm_rtas_int_on }, 130 #endif 131 }; 132 133 struct rtas_token_definition { 134 struct list_head list; 135 struct rtas_handler *handler; 136 u64 token; 137 }; 138 139 static int rtas_name_matches(char *s1, char *s2) 140 { 141 struct kvm_rtas_token_args args; 142 return !strncmp(s1, s2, sizeof(args.name)); 143 } 144 145 static int rtas_token_undefine(struct kvm *kvm, char *name) 146 { 147 struct rtas_token_definition *d, *tmp; 148 149 lockdep_assert_held(&kvm->lock); 150 151 list_for_each_entry_safe(d, tmp, &kvm->arch.rtas_tokens, list) { 152 if (rtas_name_matches(d->handler->name, name)) { 153 list_del(&d->list); 154 kfree(d); 155 return 0; 156 } 157 } 158 159 /* It's not an error to undefine an undefined token */ 160 return 0; 161 } 162 163 static int rtas_token_define(struct kvm *kvm, char *name, u64 token) 164 { 165 struct rtas_token_definition *d; 166 struct rtas_handler *h = NULL; 167 bool found; 168 int i; 169 170 lockdep_assert_held(&kvm->lock); 171 172 list_for_each_entry(d, &kvm->arch.rtas_tokens, list) { 173 if (d->token == token) 174 return -EEXIST; 175 } 176 177 found = false; 178 for (i = 0; i < ARRAY_SIZE(rtas_handlers); i++) { 179 h = &rtas_handlers[i]; 180 if (rtas_name_matches(h->name, name)) { 181 found = true; 182 break; 183 } 184 } 185 186 if (!found) 187 return -ENOENT; 188 189 d = kzalloc(sizeof(*d), GFP_KERNEL); 190 if (!d) 191 return -ENOMEM; 192 193 d->handler = h; 194 d->token = token; 195 196 list_add_tail(&d->list, &kvm->arch.rtas_tokens); 197 198 return 0; 199 } 200 201 int kvm_vm_ioctl_rtas_define_token(struct kvm *kvm, void __user *argp) 202 { 203 struct kvm_rtas_token_args args; 204 int rc; 205 206 if (copy_from_user(&args, argp, sizeof(args))) 207 return -EFAULT; 208 209 mutex_lock(&kvm->lock); 210 211 if (args.token) 212 rc = rtas_token_define(kvm, args.name, args.token); 213 else 214 rc = rtas_token_undefine(kvm, args.name); 215 216 mutex_unlock(&kvm->lock); 217 218 return rc; 219 } 220 221 int kvmppc_rtas_hcall(struct kvm_vcpu *vcpu) 222 { 223 struct rtas_token_definition *d; 224 struct rtas_args args; 225 rtas_arg_t *orig_rets; 226 gpa_t args_phys; 227 int rc; 228 229 /* 230 * r4 contains the guest physical address of the RTAS args 231 * Mask off the top 4 bits since this is a guest real address 232 */ 233 args_phys = kvmppc_get_gpr(vcpu, 4) & KVM_PAM; 234 235 rc = kvm_read_guest(vcpu->kvm, args_phys, &args, sizeof(args)); 236 if (rc) 237 goto fail; 238 239 /* 240 * args->rets is a pointer into args->args. Now that we've 241 * copied args we need to fix it up to point into our copy, 242 * not the guest args. We also need to save the original 243 * value so we can restore it on the way out. 244 */ 245 orig_rets = args.rets; 246 args.rets = &args.args[be32_to_cpu(args.nargs)]; 247 248 mutex_lock(&vcpu->kvm->lock); 249 250 rc = -ENOENT; 251 list_for_each_entry(d, &vcpu->kvm->arch.rtas_tokens, list) { 252 if (d->token == be32_to_cpu(args.token)) { 253 d->handler->handler(vcpu, &args); 254 rc = 0; 255 break; 256 } 257 } 258 259 mutex_unlock(&vcpu->kvm->lock); 260 261 if (rc == 0) { 262 args.rets = orig_rets; 263 rc = kvm_write_guest(vcpu->kvm, args_phys, &args, sizeof(args)); 264 if (rc) 265 goto fail; 266 } 267 268 return rc; 269 270 fail: 271 /* 272 * We only get here if the guest has called RTAS with a bogus 273 * args pointer. That means we can't get to the args, and so we 274 * can't fail the RTAS call. So fail right out to userspace, 275 * which should kill the guest. 276 */ 277 return rc; 278 } 279 EXPORT_SYMBOL_GPL(kvmppc_rtas_hcall); 280 281 void kvmppc_rtas_tokens_free(struct kvm *kvm) 282 { 283 struct rtas_token_definition *d, *tmp; 284 285 lockdep_assert_held(&kvm->lock); 286 287 list_for_each_entry_safe(d, tmp, &kvm->arch.rtas_tokens, list) { 288 list_del(&d->list); 289 kfree(d); 290 } 291 } 292