KVM: take mmu_lock when updating a deleted slot

kvm_handle_hva relies on mmu_lock protection to safely access
the memslot structures.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 687d113a3e5e..5fed9bfc3cf5 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1210,8 +1210,10 @@ int __kvm_set_memory_region(struct kvm *kvm,
 
         kvm_free_physmem_slot(&old, npages ? &new : NULL);
         /* Slot deletion case: we have to update the current slot */
+        spin_lock(&kvm->mmu_lock);
         if (!npages)
                 *memslot = old;
+        spin_unlock(&kvm->mmu_lock);
 #ifdef CONFIG_DMAR
         /* map the pages in iommu page table */
         r = kvm_iommu_map_pages(kvm, base_gfn, npages);