On Fri, Mar 14, 2025 at 05:24:53PM +0000, Alejandro Vallejo wrote: > With a single global count for the claims it's easy to substract > domain_tot_pages() from the claim so the number given in the hypercall > is the real reservation of the domain. This is the current behaviour. > > However, a later patch introduces exact-node claims and those interact > very poorly with such a scheme. Since accounting domain_tot_pages() in > one case but not the other seems strictly worse than not accounting them > at all (which is at least consistent), this patch stops substracting > tot_pages from the claim and instead checks that claimed memory + > allocated memory don't exceed max_mem.
Hm, while I don't have any specific interest in keeping the current behavior, XENMEM_claim_pages is part of the stable ABI (it's not a domctl), and hence should be stable. Note also the comment above the definition of XENMEM_claim_pages how it states the specific behavior that you are trying to change (and which should have been adjusted as part of this change). I have no idea why this was made a xenmem rather than a domctl hypercall, but if you want to change the semantics I think the only option is introducing a new hypercall. Thanks, Roger.
