KVM: ia64: stack get/restore patch

Implement KVM_IA64_VCPU_[GS]ET_STACK ioctl calls. This is required
for live migrations.

Patch is based on previous implementation that was part of old
GET/SET_REGS ioctl calls.

Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 89 insertions, 3 deletions

diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index de47467a0e61..1477f91617a5 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -1421,6 +1421,23 @@ int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
         return 0;
 }
 
+int kvm_arch_vcpu_ioctl_get_stack(struct kvm_vcpu *vcpu,
+                                  struct kvm_ia64_vcpu_stack *stack)
+{
+        memcpy(stack, vcpu, sizeof(struct kvm_ia64_vcpu_stack));
+        return 0;
+}
+
+int kvm_arch_vcpu_ioctl_set_stack(struct kvm_vcpu *vcpu,
+                                  struct kvm_ia64_vcpu_stack *stack)
+{
+        memcpy(vcpu + 1, &stack->stack[0] + sizeof(struct kvm_vcpu),
+               sizeof(struct kvm_ia64_vcpu_stack) - sizeof(struct kvm_vcpu));
+
+        vcpu->arch.exit_data = ((struct kvm_vcpu *)stack)->arch.exit_data;
+        return 0;
+}
+
 void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
 {
 
@@ -1430,9 +1447,78 @@ void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
 
 
 long kvm_arch_vcpu_ioctl(struct file *filp,
-                unsigned int ioctl, unsigned long arg)
+                         unsigned int ioctl, unsigned long arg)
 {
-        return -EINVAL;
+        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;
 }
 
 int kvm_arch_set_memory_region(struct kvm *kvm,
@@ -1472,7 +1558,7 @@ void kvm_arch_flush_shadow(struct kvm *kvm)
 }
 
 long kvm_arch_dev_ioctl(struct file *filp,
-                unsigned int ioctl, unsigned long arg)
+                        unsigned int ioctl, unsigned long arg)
 {
         return -EINVAL;
 }