On Fri, Jun 11, 2021 at 3:31 AM Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote: > > On 10/06/21 22:39, Jim Mattson wrote: > > But, even worse, it can modify guest memory, > > even while all vCPU threads are stopped! > > To some extent this is a userspace issue---they could declare vCPU > threads stopped only after KVM_GET_MPSTATE is done, and only start the > downtime phase of migration after that. But it is nevertheless a pretty > bad excuse. I agree that this could be fixed by documenting the behavior. Since I don't think there's any existing documentation that says which ioctls can modify guest memory, such a documentation change wouldn't actually constitute an API breakage. BTW, which ioctls can modify guest memory? And, while we're at it, can we document the required orderings of the various _GET_ and _SET_ ioctls for save and restore?
