On Thu, Feb 22, 2018 at 2:51 PM, Alastair D'Silva <alast...@au1.ibm.com> wrote: > On Thu, 2018-02-22 at 14:46 +1100, Balbir Singh wrote: > <snip> >> lpc_size could be added. It's currently useless to the library, but >> > doesn't >> > hurt. The one which was giving me troubles on a previous version of >> > this >> > patch was the lpc numa node ID, since that was experimental code >> > and felt >> > out of place considering what's been upstreamed in skiboot and >> > linux so far. >> > >> >> Yeah, I think metadata will evolve for a while till it settle's down. >> Since ocxl_ioctl_get_metadata is exposed via uapi, a newer program >> calling an older kernel will never work, since the size of that >> struct >> will always be larger than what the OS supports and our >> copy_to_user() >> will fail. The other option is for the user program to try all >> possible versions till one succeeds, that is bad as well. I think >> there are a few ways around it, if we care about this combination. >> >> Balbir Singh. >> > > We have a number of reserved members at the end of the struct which can > be re-purposed for future information (with a corresponding bump of the > version number).
Good point, agreed Balbir Singh.
