On 09.08.2017 15:01, Cornelia Huck wrote: > On Fri, 21 Jul 2017 14:56:08 +0200 > David Hildenbrand <da...@redhat.com> wrote: > > Finally got around to that one... > >> The STFLE bits for the MSA (extension) facilities simply indicate that >> the respective instructions can be executed. The QUERY subfunction can then >> be used to identify which features exactly are available. >> >> Availability of subfunctions can also vary on real hardware. For now, we >> simply implement a CPU model without any available subfunctions except >> QUERY (which is always around). >> >> As all MSA functions behave quite similarly, we can use one translation >> handler for now. Prepare the code for implementation of actual subfunctions. > > Sounds reasonable. > >> >> At least MSA is helpful for now, as older Linux kernels require this >> facility when compiled for a z9 model. Allow to enable the facilities >> for the qemu cpu model. > > Do you remember which kernels?
Basically everything before kernel version 4.13 - the patch to lift this requirement has just been merged very recently: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8aa8680aa383bf6e2ac2a7d3369097268c75f7da Thomas