+ struct kvm_vcpu *vcpu = filp->private_data;
+ void __user *argp = (void __user *)arg;
+ struct kvm_ia64_vcpu_stack *stack = NULL;
+ long r;
+
+ switch (ioctl) {
+ case KVM_IA64_VCPU_GET_STACK: {
+ struct kvm_ia64_vcpu_stack __user *user_stack;
+ void __user *first_p = argp;
+
+ r = -EFAULT;
+ if (copy_from_user(&user_stack, first_p, sizeof(void *)))
+ goto out;
+
+ if (!access_ok(VERIFY_WRITE, user_stack,
+ sizeof(struct kvm_ia64_vcpu_stack))) {
+ printk(KERN_INFO "KVM_IA64_VCPU_GET_STACK: "
+ "Illegal user destination address for stack\n");
+ goto out;
+ }
+ stack = kzalloc(sizeof(struct kvm_ia64_vcpu_stack), GFP_KERNEL);
+ if (!stack) {
+ r = -ENOMEM;
+ goto out;
+ }
+
+ r = kvm_arch_vcpu_ioctl_get_stack(vcpu, stack);
+ if (r)
+ goto out;
+
+ if (copy_to_user(user_stack, stack,
+ sizeof(struct kvm_ia64_vcpu_stack)))
+ goto out;
+
+ break;
+ }
+ case KVM_IA64_VCPU_SET_STACK: {
+ struct kvm_ia64_vcpu_stack __user *user_stack;
+ void __user *first_p = argp;
+
+ r = -EFAULT;
+ if (copy_from_user(&user_stack, first_p, sizeof(void *)))
+ goto out;
+
+ if (!access_ok(VERIFY_READ, user_stack,
+ sizeof(struct kvm_ia64_vcpu_stack))) {
+ printk(KERN_INFO "KVM_IA64_VCPU_SET_STACK: "
+ "Illegal user address for stack\n");
+ goto out;
+ }
+ stack = kmalloc(sizeof(struct kvm_ia64_vcpu_stack), GFP_KERNEL);
+ if (!stack) {
+ r = -ENOMEM;
+ goto out;
+ }
+ if (copy_from_user(stack, user_stack,
+ sizeof(struct kvm_ia64_vcpu_stack)))
+ goto out;
+
+ r = kvm_arch_vcpu_ioctl_set_stack(vcpu, stack);
+ break;
+ }
+
+ default:
+ r = -EINVAL;
+ }
+
+out:
+ kfree(stack);
+ return r;