Hi All, I was wondering if someone could help me understand some of the rules of the memory sharing implementation in Xen?
Specifically I'm looking to understand what restrictions Xen places on granting access from one Dom to another from Xen's perspective, and what types of grant requests would be allowed/rejected by Xen? I.e. How would the situation be handled if the same frame of memory was attempted to be shared multiple times? As an example scenario, DomA shares 1 physical page of memory in a transaction with DomB. And then without releasing any memory, DomA attempts to share another region of memory, which includes the same physical page of the previous share with DomB again. This would result in two concurrent shares containing an overlap. Apologies if I've missed something but is there any documentation / threat model that would cover these types of scenarios? So far I have been trying to read through the code but was wondering if there is something else I could refer to help me with my understanding? Thanks Kind Regards, Marc Bonnici
