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/iommu.c b/virt/kvm/iommu.c
index e9693a2..4c40375 100644
--- a/virt/kvm/iommu.c
+++ b/virt/kvm/iommu.c
@@ -73,14 +73,13 @@
{
int i, r = 0;
- down_read(&kvm->slots_lock);
for (i = 0; i < kvm->nmemslots; i++) {
r = kvm_iommu_map_pages(kvm, kvm->memslots[i].base_gfn,
kvm->memslots[i].npages);
if (r)
break;
}
- up_read(&kvm->slots_lock);
+
return r;
}
@@ -190,12 +189,11 @@
static int kvm_iommu_unmap_memslots(struct kvm *kvm)
{
int i;
- down_read(&kvm->slots_lock);
+
for (i = 0; i < kvm->nmemslots; i++) {
kvm_iommu_put_pages(kvm, kvm->memslots[i].base_gfn,
kvm->memslots[i].npages);
}
- up_read(&kvm->slots_lock);
return 0;
}