On 08/02/17 18:06, George Dunlap wrote: > On 08/02/17 13:20, Andrew Cooper wrote: >> On 08/02/17 13:13, Jan Beulich wrote: >>>>>> On 07.02.17 at 19:48, <andrew.coop...@citrix.com> wrote: >>>> Until the IPI has completed, other processors might be running on this >>>> nested >>>> p2m object. clear_domain_page() does not guarantee to make 8-byte atomic >>>> updates, which means that a pagewalk on a remote processor might encounter >>>> a >>>> partial update. >>>> >>>> This is currently safe as other issues prevents a nested p2m ever being >>>> shared >>>> between two cpus (although this is contrary to the original plan). >>>> >>>> Setting p2m->np2m_base to P2M_BASE_EADDR before the IPI ensures that the >>>> IPI'd >>>> processors won't continue to use the flushed mappings. >>>> >>>> While modifying this function, remove all the trailing whitespace and tweak >>>> style in the affected areas. >>>> >>>> Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com> >>> Reviewed-by: Jan Beulich <jbeul...@suse.com> >>> but ... >>> >>>> @@ -1633,19 +1635,21 @@ p2m_flush_table(struct p2m_domain *p2m) >>>> >>>> /* This is no longer a valid nested p2m for any address space */ >>>> p2m->np2m_base = P2M_BASE_EADDR; >>>> - >>>> - /* Zap the top level of the trie */ >>>> - mfn = pagetable_get_mfn(p2m_get_pagetable(p2m)); >>>> - clear_domain_page(mfn); >>>> >>>> /* Make sure nobody else is using this p2m table */ >>>> nestedhvm_vmcx_flushtlb(p2m); >>>> >>>> + /* Zap the top level of the trie */ >>> s/trie/tree/ here, as you touch it anyway? >> >> Trie here refers to the datastructure https://en.wikipedia.org/wiki/Trie >> which is the structure implemented by processor pagetables. It is more >> specific than just calling them trees. > > Never heard that before, but we seem to already have at least six > instances in the hypervisor (and an ocaml file called 'trie.mli'), so I > guess there's precedent. :-) > > Reviewed-by: George Dunlap <george.dun...@citrix.com> > > I'll check this one in.
Or maybe I won't. :-) -George _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
