diff options
Diffstat (limited to 'arch/powerpc/kvm/book3s_rtas.c')
| -rw-r--r-- | arch/powerpc/kvm/book3s_rtas.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_rtas.c b/arch/powerpc/kvm/book3s_rtas.c new file mode 100644 index 000000000000..3219ba895246 --- /dev/null +++ b/arch/powerpc/kvm/book3s_rtas.c @@ -0,0 +1,274 @@ +/* + * 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> + +#ifdef CONFIG_KVM_XICS +static void kvm_rtas_set_xive(struct kvm_vcpu *vcpu, struct rtas_args *args) +{ + u32 irq, server, priority; + int rc; + + if (args->nargs != 3 || args->nret != 1) { + rc = -3; + goto out; + } + + irq = args->args[0]; + server = args->args[1]; + priority = args->args[2]; + + rc = kvmppc_xics_set_xive(vcpu->kvm, irq, server, priority); + if (rc) + rc = -3; +out: + args->rets[0] = rc; +} + +static void kvm_rtas_get_xive(struct kvm_vcpu *vcpu, struct rtas_args *args) +{ + u32 irq, server, priority; + int rc; + + if (args->nargs != 1 || args->nret != 3) { + rc = -3; + goto out; + } + + irq = args->args[0]; + + server = priority = 0; + rc = kvmppc_xics_get_xive(vcpu->kvm, irq, &server, &priority); + if (rc) { + rc = -3; + goto out; + } + + args->rets[1] = server; + args->rets[2] = priority; +out: + args->rets[0] = rc; +} + +static void kvm_rtas_int_off(struct kvm_vcpu *vcpu, struct rtas_args *args) +{ + u32 irq; + int rc; + + if (args->nargs != 1 || args->nret != 1) { + rc = -3; + goto out; + } + + irq = args->args[0]; + + rc = kvmppc_xics_int_off(vcpu->kvm, irq); + if (rc) + rc = -3; +out: + args->rets[0] = rc; +} + +static void kvm_rtas_int_on(struct kvm_vcpu *vcpu, struct rtas_args *args) +{ + u32 irq; + int rc; + + if (args->nargs != 1 || args->nret != 1) { + rc = -3; + goto out; + } + + irq = args->args[0]; + + rc = kvmppc_xics_int_on(vcpu->kvm, irq); + if (rc) + rc = -3; +out: + args->rets[0] = rc; +} +#endif /* CONFIG_KVM_XICS */ + +struct rtas_handler { + void (*handler)(struct kvm_vcpu *vcpu, struct rtas_args *args); + char *name; +}; + +static struct rtas_handler rtas_handlers[] = { +#ifdef CONFIG_KVM_XICS + { .name = "ibm,set-xive", .handler = kvm_rtas_set_xive }, + { .name = "ibm,get-xive", .handler = kvm_rtas_get_xive }, + { .name = "ibm,int-off", .handler = kvm_rtas_int_off }, + { .name = "ibm,int-on", .handler = kvm_rtas_int_on }, +#endif +}; + +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); + } +} |