>Are there other functions also absent when z/OS is >running as a guest under z/VM? >If so, where is that documented?
I'm sure the answer to the first is "yes", and I don't know the answer to the second. But if you were to turn the question around and ask "where is it documented what you can rely on", that question can be answered for the z/OS releases that have architecture level sets. Those level sets do not say (although we tend to think of them this way) "z9 machine" (z/OS 2.1) or "z10 machine" (z/OS 2.2) but instead indicate the list of facilities which must be present. Those facilities correlate to the machine, but may not be a complete set. I'd guess that if z/OS ever level sets to the zEC12, it won't have transactional execution facility on the list of facilities (unless by then there is VM support so that it can say "if running with VM release x/y/z", or unless it chooses to say "only if not running under VM"). The compilers (I hope) -- I've tried asking them and have not gotten much of an answer -- tend to limit their exploitation of an ARCH level to those facilities that -- do not require operating system support (so that if you're running on the machine it's available) -- do not require VM support (so that it will work whether running z/OS native or under VM) -- are supported by some release of zPDT (so that you'll get correct results whether running on the machine or the "right" release of zPDT) For transactional execution, to the extent that the compiler support is to use the instruction only when the user explicitly codes something to tell you to do so, then it could be left to the user to provide whatever suitable run-time test is needed to ensure availability. Peter Relson z/OS Core Technology Design ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
