On 18/02/21 17:15, Sean Christopherson wrote:
On Thu, Feb 18, 2021, Paolo Bonzini wrote:
On 13/02/21 01:50, Sean Christopherson wrote:
- * Nothing to do for RO slots or CREATE/MOVE/DELETE of a slot.
- * See comments below.
+ * Nothing to do for RO slots (which can't be dirtied and can't be made
+ * writable) or CREATE/MOVE/DELETE of a slot. See comments below.
*/
if ((change != KVM_MR_FLAGS_ONLY) || (new->flags & KVM_MEM_READONLY))
return;
+ /*
+ * READONLY and non-flags changes were filtered out above, and the only
+ * other flag is LOG_DIRTY_PAGES, i.e. something is wrong if dirty
+ * logging isn't being toggled on or off.
+ */
+ if (WARN_ON_ONCE(!((old->flags ^ new->flags) & KVM_MEM_LOG_DIRTY_PAGES)))
+ return;
+
What about readonly -> readwrite changes?
Not allowed without first deleting the memslot. See commit 75d61fbcf563 ("KVM:
set_memory_region: Disallow changing read-only attribute later"). RW->RO is
also not supported.
if (!old.npages) {
change = KVM_MR_CREATE;
new.dirty_bitmap = NULL;
memset(&new.arch, 0, sizeof(new.arch));
} else { /* Modify an existing slot. */
if ((new.userspace_addr != old.userspace_addr) ||
(new.npages != old.npages) ||
((new.flags ^ old.flags) & KVM_MEM_READONLY))
return -EINVAL;
Right you are, thanks. Then the warning would catch this quick. I
queued 10 and 11 too, and will reply on 12 now that I looked at it more
closely.
Paolo
