KVM: Fix assigned devices circular locking dependency

[safe/jmp/linux-2.6] / virt / kvm / kvm_main.c

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index d9bbb20..29a667c 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -466,6 +466,7 @@ static int kvm_vm_ioctl_assign_device(struct kvm *kvm,
        struct kvm_assigned_dev_kernel *match;
        struct pci_dev *dev;
 
+       down_read(&kvm->slots_lock);
        mutex_lock(&kvm->lock);
 
        match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
@@ -527,6 +528,7 @@ static int kvm_vm_ioctl_assign_device(struct kvm *kvm,
 
 out:
        mutex_unlock(&kvm->lock);
+       up_read(&kvm->slots_lock);
        return r;
 out_list_del:
        list_del(&match->list);
@@ -538,6 +540,7 @@ out_put:
 out_free:
        kfree(match);
        mutex_unlock(&kvm->lock);
+       up_read(&kvm->slots_lock);
        return r;
 }
 #endif