12 files changed, 252 insertions, 1 deletions

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 149558b1e81e..fb308be8521b 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2341,6 +2341,25 @@ and distributor interface, the ioctl must be called after calling
 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
 ------------------------
diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
index 4bc2c3dad6ad..cf4df8e2139a 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -270,6 +270,9 @@
 #define H_SET_MODE              0x31C
 #define MAX_HCALL_OPCODE        H_SET_MODE
 
+/* Platform specific hcalls, used by KVM */
+#define H_RTAS                  0xf000
+
 #ifndef __ASSEMBLY__
 
 /**
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 13740a645a6d..311f7e6f09e9 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -259,6 +259,7 @@ struct kvm_arch {
 #endif /* CONFIG_KVM_BOOK3S_64_HV */
 #ifdef CONFIG_PPC_BOOK3S_64
         struct list_head spapr_tce_tables;
+        struct list_head rtas_tokens;
 #endif
 #ifdef CONFIG_KVM_MPIC
         struct openpic *mpic;
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index df9c80b37905..8a30eb7f2bec 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -166,6 +166,10 @@ extern int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *);
 
 int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq);
 
+extern int kvm_vm_ioctl_rtas_define_token(struct kvm *kvm, void __user *argp);
+extern int kvmppc_rtas_hcall(struct kvm_vcpu *vcpu);
+extern void kvmppc_rtas_tokens_free(struct kvm *kvm);
+
 /*
  * Cuts out inst bits with ordering according to spec.
  * That means the leftmost bit is zero. All given bits are included.
diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h
index 03c7819a44a3..eb9e25c194ad 100644
--- a/arch/powerpc/include/uapi/asm/kvm.h
+++ b/arch/powerpc/include/uapi/asm/kvm.h
@@ -324,6 +324,12 @@ struct kvm_allocate_rma {
         __u64 rma_size;
 };
 
+/* for KVM_CAP_PPC_RTAS */
+struct kvm_rtas_token_args {
+        char name[120];
+        __u64 token;    /* Use a token of 0 to undefine a mapping */
+};
+
 struct kvm_book3e_206_tlb_entry {
         __u32 mas8;
         __u32 mas1;
diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index 4eada0c01082..3faf5c07329c 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -86,6 +86,7 @@ kvm-book3s_64-module-objs := \
         emulate.o \
         book3s.o \
         book3s_64_vio.o \
+        book3s_rtas.o \
         $(kvm-book3s_64-objs-y)
 
 kvm-objs-$(CONFIG_KVM_BOOK3S_64) := $(kvm-book3s_64-module-objs)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 5af0f2979833..f3d7af7981c7 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -483,7 +483,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
         unsigned long req = kvmppc_get_gpr(vcpu, 3);
         unsigned long target, ret = H_SUCCESS;
         struct kvm_vcpu *tvcpu;
-        int idx;
+        int idx, rc;
 
         switch (req) {
         case H_ENTER:
@@ -519,6 +519,19 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
                                         kvmppc_get_gpr(vcpu, 5),
                                         kvmppc_get_gpr(vcpu, 6));
                 break;
+        case H_RTAS:
+                if (list_empty(&vcpu->kvm->arch.rtas_tokens))
+                        return RESUME_HOST;
+
+                rc = kvmppc_rtas_hcall(vcpu);
+
+                if (rc == -ENOENT)
+                        return RESUME_HOST;
+                else if (rc == 0)
+                        break;
+
+                /* Send the error out to userspace via KVM_RUN */
+                return rc;
         default:
                 return RESUME_HOST;
         }
@@ -1829,6 +1842,7 @@ int kvmppc_core_init_vm(struct kvm *kvm)
         cpumask_setall(&kvm->arch.need_tlb_flush);
 
         INIT_LIST_HEAD(&kvm->arch.spapr_tce_tables);
+        INIT_LIST_HEAD(&kvm->arch.rtas_tokens);
 
         kvm->arch.rma = NULL;
 
@@ -1874,6 +1888,8 @@ void kvmppc_core_destroy_vm(struct kvm *kvm)
                 kvm->arch.rma = NULL;
         }
 
+        kvmppc_rtas_tokens_free(kvm);
+
         kvmppc_free_hpt(kvm);
         WARN_ON(!list_empty(&kvm->arch.spapr_tce_tables));
 }
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index c1cffa882a69..d09baf143500 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -1296,6 +1296,7 @@ int kvmppc_core_init_vm(struct kvm *kvm)
 {
 #ifdef CONFIG_PPC64
         INIT_LIST_HEAD(&kvm->arch.spapr_tce_tables);
+        INIT_LIST_HEAD(&kvm->arch.rtas_tokens);
 #endif
 
         if (firmware_has_feature(FW_FEATURE_SET_MODE)) {
diff --git a/arch/powerpc/kvm/book3s_pr_papr.c b/arch/powerpc/kvm/book3s_pr_papr.c
index ee02b30878ed..4efa4a4f3722 100644
--- a/arch/powerpc/kvm/book3s_pr_papr.c
+++ b/arch/powerpc/kvm/book3s_pr_papr.c
@@ -246,6 +246,13 @@ int kvmppc_h_pr(struct kvm_vcpu *vcpu, unsigned long cmd)
                 clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
                 vcpu->stat.halt_wakeup++;
                 return EMULATE_DONE;
+        case H_RTAS:
+                if (list_empty(&vcpu->kvm->arch.rtas_tokens))
+                        return RESUME_HOST;
+                if (kvmppc_rtas_hcall(vcpu))
+                        break;
+                kvmppc_set_gpr(vcpu, 3, 0);
+                return EMULATE_DONE;
         }
 
         return EMULATE_FAIL;
diff --git a/arch/powerpc/kvm/book3s_rtas.c b/arch/powerpc/kvm/book3s_rtas.c
new file mode 100644
index 000000000000..6ad7050eb67d
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_rtas.c
@@ -0,0 +1,182 @@
+/*
+ * 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);
+        }
+}
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index d8e81e6c1afe..d4fd443ae7bd 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -341,6 +341,7 @@ int kvm_dev_ioctl_check_extension(long ext)
 #ifdef CONFIG_PPC_BOOK3S_64
         case KVM_CAP_SPAPR_TCE:
         case KVM_CAP_PPC_ALLOC_HTAB:
+        case KVM_CAP_PPC_RTAS:
                 r = 1;
                 break;
 #endif /* CONFIG_PPC_BOOK3S_64 */
@@ -986,6 +987,7 @@ long kvm_arch_vm_ioctl(struct file *filp,
 #ifdef CONFIG_KVM_BOOK3S_64_HV
         case KVM_ALLOCATE_RMA: {
                 struct kvm_allocate_rma rma;
+                struct kvm *kvm = filp->private_data;
 
                 r = kvm_vm_ioctl_allocate_rma(kvm, &rma);
                 if (r >= 0 && copy_to_user(argp, &rma, sizeof(rma)))
@@ -1030,6 +1032,12 @@ long kvm_arch_vm_ioctl(struct file *filp,
                         r = -EFAULT;
                 break;
         }
+        case KVM_PPC_RTAS_DEFINE_TOKEN: {
+                struct kvm *kvm = filp->private_data;
+
+                r = kvm_vm_ioctl_rtas_define_token(kvm, argp);
+                break;
+        }
 #endif /* CONFIG_PPC_BOOK3S_64 */
         default:
                 r = -ENOTTY;
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 0ebf59b50ed0..d4005192ad6e 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -668,6 +668,7 @@ struct kvm_ppc_smmu_info {
 #define KVM_CAP_ARM_SET_DEVICE_ADDR 88
 #define KVM_CAP_DEVICE_CTRL 89
 #define KVM_CAP_IRQ_MPIC 90
+#define KVM_CAP_PPC_RTAS 91
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
@@ -928,6 +929,8 @@ struct kvm_s390_ucas_mapping {
 #define KVM_PPC_GET_HTAB_FD       _IOW(KVMIO,  0xaa, struct kvm_get_htab_fd)
 /* Available with KVM_CAP_ARM_SET_DEVICE_ADDR */
 #define KVM_ARM_SET_DEVICE_ADDR   _IOW(KVMIO,  0xab, struct kvm_arm_device_addr)
+/* Available with KVM_CAP_PPC_RTAS */
+#define KVM_PPC_RTAS_DEFINE_TOKEN _IOW(KVMIO,  0xac, struct kvm_rtas_token_args)
 
 /* ioctl for vm fd */
 #define KVM_CREATE_DEVICE         _IOWR(KVMIO,  0xe0, struct kvm_create_device)