KVM_CREATE_IRQCHIP, but before calling KVM_RUN on any of the VCPUs. Calling
this ioctl twice for any of the base addresses will return -EEXIST.
+4.82 KVM_PPC_RTAS_DEFINE_TOKEN
+
+Capability: KVM_CAP_PPC_RTAS
+Architectures: ppc
+Type: vm ioctl
+Parameters: struct kvm_rtas_token_args
+Returns: 0 on success, -1 on error
+
+Defines a token value for a RTAS (Run Time Abstraction Services)
+service in order to allow it to be handled in the kernel. The
+argument struct gives the name of the service, which must be the name
+of a service that has a kernel-side implementation. If the token
+value is non-zero, it will be associated with that service, and
+subsequent RTAS calls by the guest specifying that token will be
+handled by the kernel. If the token value is 0, then any token
+associated with the service will be forgotten, and subsequent RTAS
+calls by the guest for that service will be passed to userspace to be
+handled.
+
5. The kvm_run structure
------------------------
--- /dev/null
+/*
+ * Copyright 2012 Michael Ellerman, IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/kvm_host.h>
+#include <linux/kvm.h>
+#include <linux/err.h>
+
+#include <asm/uaccess.h>
+#include <asm/kvm_book3s.h>
+#include <asm/kvm_ppc.h>
+#include <asm/hvcall.h>
+#include <asm/rtas.h>
+
+
+struct rtas_handler {
+ void (*handler)(struct kvm_vcpu *vcpu, struct rtas_args *args);
+ char *name;
+};
+
+static struct rtas_handler rtas_handlers[] = { };
+
+struct rtas_token_definition {
+ struct list_head list;
+ struct rtas_handler *handler;
+ u64 token;
+};
+
+static int rtas_name_matches(char *s1, char *s2)
+{
+ struct kvm_rtas_token_args args;
+ return !strncmp(s1, s2, sizeof(args.name));
+}
+
+static int rtas_token_undefine(struct kvm *kvm, char *name)
+{
+ struct rtas_token_definition *d, *tmp;
+
+ lockdep_assert_held(&kvm->lock);
+
+ list_for_each_entry_safe(d, tmp, &kvm->arch.rtas_tokens, list) {
+ if (rtas_name_matches(d->handler->name, name)) {
+ list_del(&d->list);
+ kfree(d);
+ return 0;
+ }
+ }
+
+ /* It's not an error to undefine an undefined token */
+ return 0;
+}
+
+static int rtas_token_define(struct kvm *kvm, char *name, u64 token)
+{
+ struct rtas_token_definition *d;
+ struct rtas_handler *h = NULL;
+ bool found;
+ int i;
+
+ lockdep_assert_held(&kvm->lock);
+
+ list_for_each_entry(d, &kvm->arch.rtas_tokens, list) {
+ if (d->token == token)
+ return -EEXIST;
+ }
+
+ found = false;
+ for (i = 0; i < ARRAY_SIZE(rtas_handlers); i++) {
+ h = &rtas_handlers[i];
+ if (rtas_name_matches(h->name, name)) {
+ found = true;
+ break;
+ }
+ }
+
+ if (!found)
+ return -ENOENT;
+
+ d = kzalloc(sizeof(*d), GFP_KERNEL);
+ if (!d)
+ return -ENOMEM;
+
+ d->handler = h;
+ d->token = token;
+
+ list_add_tail(&d->list, &kvm->arch.rtas_tokens);
+
+ return 0;
+}
+
+int kvm_vm_ioctl_rtas_define_token(struct kvm *kvm, void __user *argp)
+{
+ struct kvm_rtas_token_args args;
+ int rc;
+
+ if (copy_from_user(&args, argp, sizeof(args)))
+ return -EFAULT;
+
+ mutex_lock(&kvm->lock);
+
+ if (args.token)
+ rc = rtas_token_define(kvm, args.name, args.token);
+ else
+ rc = rtas_token_undefine(kvm, args.name);
+
+ mutex_unlock(&kvm->lock);
+
+ return rc;
+}
+
+int kvmppc_rtas_hcall(struct kvm_vcpu *vcpu)
+{
+ struct rtas_token_definition *d;
+ struct rtas_args args;
+ rtas_arg_t *orig_rets;
+ gpa_t args_phys;
+ int rc;
+
+ /* r4 contains the guest physical address of the RTAS args */
+ args_phys = kvmppc_get_gpr(vcpu, 4);
+
+ rc = kvm_read_guest(vcpu->kvm, args_phys, &args, sizeof(args));
+ if (rc)
+ goto fail;
+
+ /*
+ * args->rets is a pointer into args->args. Now that we've
+ * copied args we need to fix it up to point into our copy,
+ * not the guest args. We also need to save the original
+ * value so we can restore it on the way out.
+ */
+ orig_rets = args.rets;
+ args.rets = &args.args[args.nargs];
+
+ mutex_lock(&vcpu->kvm->lock);
+
+ rc = -ENOENT;
+ list_for_each_entry(d, &vcpu->kvm->arch.rtas_tokens, list) {
+ if (d->token == args.token) {
+ d->handler->handler(vcpu, &args);
+ rc = 0;
+ break;
+ }
+ }
+
+ mutex_unlock(&vcpu->kvm->lock);
+
+ if (rc == 0) {
+ args.rets = orig_rets;
+ rc = kvm_write_guest(vcpu->kvm, args_phys, &args, sizeof(args));
+ if (rc)
+ goto fail;
+ }
+
+ return rc;
+
+fail:
+ /*
+ * We only get here if the guest has called RTAS with a bogus
+ * args pointer. That means we can't get to the args, and so we
+ * can't fail the RTAS call. So fail right out to userspace,
+ * which should kill the guest.
+ */
+ return rc;
+}
+
+void kvmppc_rtas_tokens_free(struct kvm *kvm)
+{
+ struct rtas_token_definition *d, *tmp;
+
+ lockdep_assert_held(&kvm->lock);
+
+ list_for_each_entry_safe(d, tmp, &kvm->arch.rtas_tokens, list) {
+ list_del(&d->list);
+ kfree(d);
+ }
+}
projects / linux-imx.git / commitdiff