Commit 9c695d42 authored Dec 10, 2012 by Alex Williamson Committed by Marcelo Tosatti Dec 13, 2012

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>

parent f0736cf0

virt/kvm/kvm_main.c

+7 −1

Original line number	Diff line number	Diff line
		@@ -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 */

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