1 files changed, 274 insertions, 0 deletions

diff --git a/arch/s390/kvm/gaccess.h b/arch/s390/kvm/gaccess.h
new file mode 100644
index 000000000000..4e0633c413f3
--- /dev/null
+++ b/arch/s390/kvm/gaccess.h
@@ -0,0 +1,274 @@
+/*
+ * gaccess.h -  access guest memory
+ *
+ * Copyright IBM Corp. 2008
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License (version 2 only)
+ * as published by the Free Software Foundation.
+ *
+ *    Author(s): Carsten Otte <cotte@de.ibm.com>
+ */
+
+#ifndef __KVM_S390_GACCESS_H
+#define __KVM_S390_GACCESS_H
+
+#include <linux/compiler.h>
+#include <linux/kvm_host.h>
+#include <asm/uaccess.h>
+
+static inline void __user *__guestaddr_to_user(struct kvm_vcpu *vcpu,
+                                               u64 guestaddr)
+{
+        u64 prefix  = vcpu->arch.sie_block->prefix;
+        u64 origin  = vcpu->kvm->arch.guest_origin;
+        u64 memsize = vcpu->kvm->arch.guest_memsize;
+
+        if (guestaddr < 2 * PAGE_SIZE)
+                guestaddr += prefix;
+        else if ((guestaddr >= prefix) && (guestaddr < prefix + 2 * PAGE_SIZE))
+                guestaddr -= prefix;
+
+        if (guestaddr > memsize)
+                return (void __user __force *) ERR_PTR(-EFAULT);
+
+        guestaddr += origin;
+
+        return (void __user *) guestaddr;
+}
+
+static inline int get_guest_u64(struct kvm_vcpu *vcpu, u64 guestaddr,
+                                u64 *result)
+{
+        void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
+
+        BUG_ON(guestaddr & 7);
+
+        if (IS_ERR((void __force *) uptr))
+                return PTR_ERR((void __force *) uptr);
+
+        return get_user(*result, (u64 __user *) uptr);
+}
+
+static inline int get_guest_u32(struct kvm_vcpu *vcpu, u64 guestaddr,
+                                u32 *result)
+{
+        void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
+
+        BUG_ON(guestaddr & 3);
+
+        if (IS_ERR((void __force *) uptr))
+                return PTR_ERR((void __force *) uptr);
+
+        return get_user(*result, (u32 __user *) uptr);
+}
+
+static inline int get_guest_u16(struct kvm_vcpu *vcpu, u64 guestaddr,
+                                u16 *result)
+{
+        void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
+
+        BUG_ON(guestaddr & 1);
+
+        if (IS_ERR(uptr))
+                return PTR_ERR(uptr);
+
+        return get_user(*result, (u16 __user *) uptr);
+}
+
+static inline int get_guest_u8(struct kvm_vcpu *vcpu, u64 guestaddr,
+                               u8 *result)
+{
+        void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
+
+        if (IS_ERR((void __force *) uptr))
+                return PTR_ERR((void __force *) uptr);
+
+        return get_user(*result, (u8 __user *) uptr);
+}
+
+static inline int put_guest_u64(struct kvm_vcpu *vcpu, u64 guestaddr,
+                                u64 value)
+{
+        void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
+
+        BUG_ON(guestaddr & 7);
+
+        if (IS_ERR((void __force *) uptr))
+                return PTR_ERR((void __force *) uptr);
+
+        return put_user(value, (u64 __user *) uptr);
+}
+
+static inline int put_guest_u32(struct kvm_vcpu *vcpu, u64 guestaddr,
+                                u32 value)
+{
+        void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
+
+        BUG_ON(guestaddr & 3);
+
+        if (IS_ERR((void __force *) uptr))
+                return PTR_ERR((void __force *) uptr);
+
+        return put_user(value, (u32 __user *) uptr);
+}
+
+static inline int put_guest_u16(struct kvm_vcpu *vcpu, u64 guestaddr,
+                                u16 value)
+{
+        void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
+
+        BUG_ON(guestaddr & 1);
+
+        if (IS_ERR((void __force *) uptr))
+                return PTR_ERR((void __force *) uptr);
+
+        return put_user(value, (u16 __user *) uptr);
+}
+
+static inline int put_guest_u8(struct kvm_vcpu *vcpu, u64 guestaddr,
+                               u8 value)
+{
+        void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
+
+        if (IS_ERR((void __force *) uptr))
+                return PTR_ERR((void __force *) uptr);
+
+        return put_user(value, (u8 __user *) uptr);
+}
+
+
+static inline int __copy_to_guest_slow(struct kvm_vcpu *vcpu, u64 guestdest,
+                                       const void *from, unsigned long n)
+{
+        int rc;
+        unsigned long i;
+        const u8 *data = from;
+
+        for (i = 0; i < n; i++) {
+                rc = put_guest_u8(vcpu, guestdest++, *(data++));
+                if (rc < 0)
+                        return rc;
+        }
+        return 0;
+}
+
+static inline int copy_to_guest(struct kvm_vcpu *vcpu, u64 guestdest,
+                                const void *from, unsigned long n)
+{
+        u64 prefix  = vcpu->arch.sie_block->prefix;
+        u64 origin  = vcpu->kvm->arch.guest_origin;
+        u64 memsize = vcpu->kvm->arch.guest_memsize;
+
+        if ((guestdest < 2 * PAGE_SIZE) && (guestdest + n > 2 * PAGE_SIZE))
+                goto slowpath;
+
+        if ((guestdest < prefix) && (guestdest + n > prefix))
+                goto slowpath;
+
+        if ((guestdest < prefix + 2 * PAGE_SIZE)
+            && (guestdest + n > prefix + 2 * PAGE_SIZE))
+                goto slowpath;
+
+        if (guestdest < 2 * PAGE_SIZE)
+                guestdest += prefix;
+        else if ((guestdest >= prefix) && (guestdest < prefix + 2 * PAGE_SIZE))
+                guestdest -= prefix;
+
+        if (guestdest + n > memsize)
+                return -EFAULT;
+
+        if (guestdest + n < guestdest)
+                return -EFAULT;
+
+        guestdest += origin;
+
+        return copy_to_user((void __user *) guestdest, from, n);
+slowpath:
+        return __copy_to_guest_slow(vcpu, guestdest, from, n);
+}
+
+static inline int __copy_from_guest_slow(struct kvm_vcpu *vcpu, void *to,
+                                         u64 guestsrc, unsigned long n)
+{
+        int rc;
+        unsigned long i;
+        u8 *data = to;
+
+        for (i = 0; i < n; i++) {
+                rc = get_guest_u8(vcpu, guestsrc++, data++);
+                if (rc < 0)
+                        return rc;
+        }
+        return 0;
+}
+
+static inline int copy_from_guest(struct kvm_vcpu *vcpu, void *to,
+                                  u64 guestsrc, unsigned long n)
+{
+        u64 prefix  = vcpu->arch.sie_block->prefix;
+        u64 origin  = vcpu->kvm->arch.guest_origin;
+        u64 memsize = vcpu->kvm->arch.guest_memsize;
+
+        if ((guestsrc < 2 * PAGE_SIZE) && (guestsrc + n > 2 * PAGE_SIZE))
+                goto slowpath;
+
+        if ((guestsrc < prefix) && (guestsrc + n > prefix))
+                goto slowpath;
+
+        if ((guestsrc < prefix + 2 * PAGE_SIZE)
+            && (guestsrc + n > prefix + 2 * PAGE_SIZE))
+                goto slowpath;
+
+        if (guestsrc < 2 * PAGE_SIZE)
+                guestsrc += prefix;
+        else if ((guestsrc >= prefix) && (guestsrc < prefix + 2 * PAGE_SIZE))
+                guestsrc -= prefix;
+
+        if (guestsrc + n > memsize)
+                return -EFAULT;
+
+        if (guestsrc + n < guestsrc)
+                return -EFAULT;
+
+        guestsrc += origin;
+
+        return copy_from_user(to, (void __user *) guestsrc, n);
+slowpath:
+        return __copy_from_guest_slow(vcpu, to, guestsrc, n);
+}
+
+static inline int copy_to_guest_absolute(struct kvm_vcpu *vcpu, u64 guestdest,
+                                         const void *from, unsigned long n)
+{
+        u64 origin  = vcpu->kvm->arch.guest_origin;
+        u64 memsize = vcpu->kvm->arch.guest_memsize;
+
+        if (guestdest + n > memsize)
+                return -EFAULT;
+
+        if (guestdest + n < guestdest)
+                return -EFAULT;
+
+        guestdest += origin;
+
+        return copy_to_user((void __user *) guestdest, from, n);
+}
+
+static inline int copy_from_guest_absolute(struct kvm_vcpu *vcpu, void *to,
+                                           u64 guestsrc, unsigned long n)
+{
+        u64 origin  = vcpu->kvm->arch.guest_origin;
+        u64 memsize = vcpu->kvm->arch.guest_memsize;
+
+        if (guestsrc + n > memsize)
+                return -EFAULT;
+
+        if (guestsrc + n < guestsrc)
+                return -EFAULT;
+
+        guestsrc += origin;
+
+        return copy_from_user(to, (void __user *) guestsrc, n);
+}
+#endif