On 24/08/2020 13:34, Jan Beulich wrote: > While in most cases code ahead of the invocation of set_gpfn_from_mfn() > deals with shared pages, at least in set_typed_p2m_entry() I can't spot > such handling (it's entirely possible there's code missing there). Let's > try to play safe and add an extra check. > > Signed-off-by: Jan Beulich <jbeul...@suse.com>
I agree that this is an improvement. Therefore, tentatively Acked-by: Andrew Cooper <andrew.coop...@citrix.com> However, I don't think it is legitimate for set_gpfn_from_mfn() to be overriding anything. IMO, we should be asserting something like (pfn == SHARED_M2P_ENTRY) == (d == dom_cow). Any code not passing this properly is almost certainly broken anyway, and fixing up behind its back like this doesn't feel like a clever idea (in debug builds at least). ~Andrew
