@@ -779,13 +779,19 @@ 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 */
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. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> --- virt/kvm/kvm_main.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html