diff options
authorAlex Williamson <alex.williamson@redhat.com>2012-12-10 10:32:51 -0700
committerMarcelo Tosatti <mtosatti@redhat.com>2012-12-13 23:21:51 -0200
commit9c695d42dbd465bcaa865603b411a73c60e60978 (patch)
parentf0736cf0550b349a5d5a374d65ca0488cc2eee40 (diff)
KVM: Check userspace_addr when modifying a memory slot
The API documents that only flags and guest physical memory space can be modified on an existing slot, but we don't enforce that the userspace address cannot be modified. Instead we just ignore it. This means that a user may think they've successfully moved both the guest and user addresses, when in fact only the guest address changed. Check and error instead. Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
1 files changed, 7 insertions, 1 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 3caf8162eb6..e4d358195e5 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -784,13 +784,19 @@ int __kvm_set_memory_region(struct kvm *kvm,
r = -ENOMEM;
- /* Allocate if a slot is being created */
+ /*
+ * Allocate if a slot is being created. If modifying a slot,
+ * the userspace_addr cannot change.
+ */
if (!old.npages) {
new.user_alloc = user_alloc;
new.userspace_addr = mem->userspace_addr;
if (kvm_arch_create_memslot(&new, npages))
goto out_free;
+ } else if (npages && mem->userspace_addr != old.userspace_addr) {
+ r = -EINVAL;
+ goto out_free;
/* Allocate page dirty bitmap if needed */