On 05.01.2021 14:38, Andrew Cooper wrote: > On 05/01/2021 13:24, Jan Beulich wrote: >> Even more so when using rcu_lock_domain_by_id() in place of the more >> efficient rcu_lock_current_domain(). >> >> Signed-off-by: Jan Beulich <jbeul...@suse.com> > > Acked-by: Andrew Cooper <andrew.coop...@citrix.com>
Thanks. >> --- >> Besides get_pg_owner(), gnttab_copy_lock_domain() has similar strange(?) >> behavior: They accept DOMID_SELF, but not the resolved ID of the caller. > > I queried that behaviour years and years ago. > > According to Keir, it is part of the attempt to force guests to not know > their own domid. Xen itself does (or did) its very hardest to prevent a > domU knowing its own domid, while at the same time the "domid" key in > xenstore is mandatory for setting up PV rings. > > I'd personally think was a short sighted move. Let me make another patch then, unless you can see reasons we should stick to the current behavior. Figuring out its own domid is possible for a domain, after all, and even shouldn't be overly difficult. Jan
