KVM: Fix assigned devices circular locking dependency
kvm->slots_lock is outer to kvm->lock, so take slots_lock
in kvm_vm_ioctl_assign_device() before taking kvm->lock,
rather than taking it in kvm_iommu_map_memslots().
Cc: stable@kernel.org
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index d9bbb20..29a667c 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -466,6 +466,7 @@
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 @@
out:
mutex_unlock(&kvm->lock);
+ up_read(&kvm->slots_lock);
return r;
out_list_del:
list_del(&match->list);
@@ -538,6 +540,7 @@
out_free:
kfree(match);
mutex_unlock(&kvm->lock);
+ up_read(&kvm->slots_lock);
return r;
}
#endif