2 * Copyright 2012 Michael Ellerman, IBM Corporation.
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.
9 #include <linux/kernel.h>
10 #include <linux/kvm_host.h>
11 #include <linux/kvm.h>
12 #include <linux/err.h>
14 #include <asm/uaccess.h>
15 #include <asm/kvm_book3s.h>
16 #include <asm/kvm_ppc.h>
17 #include <asm/hvcall.h>
20 #ifdef CONFIG_KVM_XICS
21 static void kvm_rtas_set_xive(struct kvm_vcpu *vcpu, struct rtas_args *args)
23 u32 irq, server, priority;
26 if (args->nargs != 3 || args->nret != 1) {
32 server = args->args[1];
33 priority = args->args[2];
35 rc = kvmppc_xics_set_xive(vcpu->kvm, irq, server, priority);
42 static void kvm_rtas_get_xive(struct kvm_vcpu *vcpu, struct rtas_args *args)
44 u32 irq, server, priority;
47 if (args->nargs != 1 || args->nret != 3) {
54 server = priority = 0;
55 rc = kvmppc_xics_get_xive(vcpu->kvm, irq, &server, &priority);
61 args->rets[1] = server;
62 args->rets[2] = priority;
67 static void kvm_rtas_int_off(struct kvm_vcpu *vcpu, struct rtas_args *args)
72 if (args->nargs != 1 || args->nret != 1) {
79 rc = kvmppc_xics_int_off(vcpu->kvm, irq);
86 static void kvm_rtas_int_on(struct kvm_vcpu *vcpu, struct rtas_args *args)
91 if (args->nargs != 1 || args->nret != 1) {
98 rc = kvmppc_xics_int_on(vcpu->kvm, irq);
104 #endif /* CONFIG_KVM_XICS */
106 struct rtas_handler {
107 void (*handler)(struct kvm_vcpu *vcpu, struct rtas_args *args);
111 static struct rtas_handler rtas_handlers[] = {
112 #ifdef CONFIG_KVM_XICS
113 { .name = "ibm,set-xive", .handler = kvm_rtas_set_xive },
114 { .name = "ibm,get-xive", .handler = kvm_rtas_get_xive },
115 { .name = "ibm,int-off", .handler = kvm_rtas_int_off },
116 { .name = "ibm,int-on", .handler = kvm_rtas_int_on },
120 struct rtas_token_definition {
121 struct list_head list;
122 struct rtas_handler *handler;
126 static int rtas_name_matches(char *s1, char *s2)
128 struct kvm_rtas_token_args args;
129 return !strncmp(s1, s2, sizeof(args.name));
132 static int rtas_token_undefine(struct kvm *kvm, char *name)
134 struct rtas_token_definition *d, *tmp;
136 lockdep_assert_held(&kvm->lock);
138 list_for_each_entry_safe(d, tmp, &kvm->arch.rtas_tokens, list) {
139 if (rtas_name_matches(d->handler->name, name)) {
146 /* It's not an error to undefine an undefined token */
150 static int rtas_token_define(struct kvm *kvm, char *name, u64 token)
152 struct rtas_token_definition *d;
153 struct rtas_handler *h = NULL;
157 lockdep_assert_held(&kvm->lock);
159 list_for_each_entry(d, &kvm->arch.rtas_tokens, list) {
160 if (d->token == token)
165 for (i = 0; i < ARRAY_SIZE(rtas_handlers); i++) {
166 h = &rtas_handlers[i];
167 if (rtas_name_matches(h->name, name)) {
176 d = kzalloc(sizeof(*d), GFP_KERNEL);
183 list_add_tail(&d->list, &kvm->arch.rtas_tokens);
188 int kvm_vm_ioctl_rtas_define_token(struct kvm *kvm, void __user *argp)
190 struct kvm_rtas_token_args args;
193 if (copy_from_user(&args, argp, sizeof(args)))
196 mutex_lock(&kvm->lock);
199 rc = rtas_token_define(kvm, args.name, args.token);
201 rc = rtas_token_undefine(kvm, args.name);
203 mutex_unlock(&kvm->lock);
208 int kvmppc_rtas_hcall(struct kvm_vcpu *vcpu)
210 struct rtas_token_definition *d;
211 struct rtas_args args;
212 rtas_arg_t *orig_rets;
216 /* r4 contains the guest physical address of the RTAS args */
217 args_phys = kvmppc_get_gpr(vcpu, 4);
219 rc = kvm_read_guest(vcpu->kvm, args_phys, &args, sizeof(args));
224 * args->rets is a pointer into args->args. Now that we've
225 * copied args we need to fix it up to point into our copy,
226 * not the guest args. We also need to save the original
227 * value so we can restore it on the way out.
229 orig_rets = args.rets;
230 args.rets = &args.args[args.nargs];
232 mutex_lock(&vcpu->kvm->lock);
235 list_for_each_entry(d, &vcpu->kvm->arch.rtas_tokens, list) {
236 if (d->token == args.token) {
237 d->handler->handler(vcpu, &args);
243 mutex_unlock(&vcpu->kvm->lock);
246 args.rets = orig_rets;
247 rc = kvm_write_guest(vcpu->kvm, args_phys, &args, sizeof(args));
256 * We only get here if the guest has called RTAS with a bogus
257 * args pointer. That means we can't get to the args, and so we
258 * can't fail the RTAS call. So fail right out to userspace,
259 * which should kill the guest.
263 EXPORT_SYMBOL_GPL(kvmppc_rtas_hcall);
265 void kvmppc_rtas_tokens_free(struct kvm *kvm)
267 struct rtas_token_definition *d, *tmp;
269 lockdep_assert_held(&kvm->lock);
271 list_for_each_entry_safe(d, tmp, &kvm->arch.rtas_tokens, list) {