On 08/27/2012 10:14 AM, Jan Kiszka wrote: > > > > Deregistration is fine, the problem is destruction. > > > > It isn't as you access memory region states that can change after > deregistration. Devices can remove memory regions from the mapping, > alter and then reinsert them. The last to steps must not happen while > anyone is still using a reference to that region. >
Why not? If the guest is accessing an mmio region while reconfiguring it in a way that changes its meaning, either the previous or the next meaning is valid. It is true that memory_region_set_enabled(..., false) will become weaker as a result. Code will have to be prepared for that. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.
