On 20.12.2019 15:26, George Dunlap wrote: > On 12/20/19 2:21 PM, Jan Beulich wrote: >> In ept_p2m_type_to_flags() passing in type and access as separate >> parameters can be considered an optimization, as all callers set the >> respective fields in the entry being updated before the call. Retain >> this behavior but add assertions. >> >> Signed-off-by: Jan Beulich <jbeul...@suse.com> > > In what way is it an optimization?
There's no pointer de-ref needed; the values will already come in via registers. And "can be considered" because possibly some compilers are smart enough to eliminate the pointer de-ref again (but then it'll still be a bitfield extract, which callers may be able to avoid). > I don't necessarily oppose this, but given that 3 of the 4 callers > literally do something like: > > ept_p2m_type_to_flags(p2m, &e, e.sa_p2mt, e.access); > > It seems like just getting rid of the extraneous arguments might a be > better option. That was my original intention as well, but iirc Andrew didn't like it when we discussed it back then (the context here being XSA-304). Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
