On 01/22/2018 12:23 PM, David Hildenbrand wrote: > On 13.12.2017 13:53, Janosch Frank wrote: >> Since the z10 s390 does support 1M pages, but whereas hugetlbfs >> support was added quite fast, KVM always used standard 4k pages for >> guest backings. >> >> This patchset adds full support for 1M huge page backings for s390 >> KVM guests. I.e. we also support VSIE (nested vms) for these guests >> and are therefore able to run all combinations of backings for all >> layers of guests. >> >> When running a VSIE guest in a huge page backed guest, we need to >> split some huge pages to be able to set granular protection. This way >> we avoid a prot/unprot cycle if prefixes and VSIE pages containing >> level 3 gmap DAT tables share the same segment, as the prefix has to >> be accessible at all times and the VSIE page has to be write >> protected. >> >> TODO: >> * Cleanups & Documentation >> * Refactoring to get rid of a lot of indents >> * Find a way to reduce or beautify bit checks on table entries >> * Storage key support for split pages (will be a separate bugfix) >> * Regression testing >> * Testing large setups >> * Testing multi level VSIE >> >> V2: >> * Incorporated changes from David's cleanup >> * Now flushing with IDTE_NODAT for protection transfers. >> * Added RRBE huge page handling for g2 -> g3 skey emulation >> * Added documentation for capability >> * Renamed GMAP_ENTRY_* constants >> * Added SEGMENT hardware bits constants >> * Improved some patch descriptions >> * General small improvements >> * Introduced pte_from_pmd function >> >> Accomplished testing: >> l2: KVM guest >> l3: nested KVM guest >> >> * 1m l2 guests >> * VSIE (l3) 4k and 1m guests on 1m l2 >> * 1m l2 -> l2 migration with 4k/1m l3 guests >> * l3 -> l2 migration >> * postcopy works every second try, seems to be QEMU or my setup >> >> >> The initial prototype was started by Dominik Dingel. I had the >> pleasure of adding the VSIE part, the protection transfers and the >> optimizations. A huge thanks to Christian and Martin who review(ed) >> and helped debugging/designing. >> > > Do you have a branch somewhere? I can't find a branch where this applies > cleanly. Thanks Pushed to git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux.git hlp_vsie https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux.git/log/?h=hlp_vsie Thanks for looking into that. -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
