On Tue, Jun 10, 2025 at 02:23:26PM +0200, Jan Beulich wrote: > On 05.06.2025 18:42, Roger Pau Monné wrote: > > 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. > > Is that true? It sits inside a > > #if defined(__XEN__) || defined(__XEN_TOOLS__) > > which generally de-marks unstable (tools-only) interfaces.
Ops, my bad, I didn't realize it was inside such region. > > 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). > > This is the more important part, imo. I see. Well, it's in a kind of a weird position then, because there's no equivalent of XEN_DOMCTL_INTERFACE_VERSION that we could use to signal callers of the changed interface, like we do for domctl. Thanks, Roger.
