FWIW, this patch set has survived some testing on my side (with storage keys, with VSIE, with both), so I would say that after a respin with some patch sqashing we give it some more days for the last reviews and then apply the whole thing via a topic branch via Martins s390 tree. I will merge this branch as well to solve the potential conflicts with Davids patch ( s390x/mm: cleanup gmap_pte_op_walk() ) which is still pending in my tree Christian On 12/13/2017 01:53 PM, 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. > > Dominik Dingel (2): > s390/mm: hugetlb pages within a gmap can not be freed > s390/mm: clear huge page storage keys on enable_skey > > Janosch Frank (20): > s390/mm: make gmap_protect_range more modular > s390/mm: Abstract gmap notify bit setting > s390/mm: add gmap PMD invalidation notification > s390/mm: Add gmap pmd invalidation and clearing > s390/mm: Introduce gmap_pmdp_xchg > RFC: s390/mm: Transfer guest pmd protection to host > s390/mm: Add huge page dirty sync support > s390/mm: Add huge pmd storage key handling > s390/mm: Remove superfluous parameter > s390/mm: Add gmap_protect_large read protection support > s390/mm: Make gmap_read_table EDAT1 compatible > s390/mm: Make protect_rmap EDAT1 compatible > s390/mm: GMAP read table extensions > s390/mm: Add shadow segment code > s390/mm: Add VSIE reverse fake case > s390/mm: Remove gmap_pte_op_walk > s390/mm: Split huge pages if granular protection is needed > s390/mm: Enable gmap huge pmd support > KVM: s390: Add KVM HPAGE capability > RFC: s390/mm: Add gmap lock classes > > Documentation/virtual/kvm/api.txt | 10 + > arch/s390/include/asm/gmap.h | 39 +- > arch/s390/include/asm/pgtable.h | 18 +- > arch/s390/kvm/gaccess.c | 64 +- > arch/s390/kvm/kvm-s390.c | 19 +- > arch/s390/mm/fault.c | 10 +- > arch/s390/mm/gmap.c | 1275 +++++++++++++++++++++++++++++++++---- > arch/s390/mm/pageattr.c | 6 +- > arch/s390/mm/pgtable.c | 176 ++++- > include/uapi/linux/kvm.h | 1 + > 10 files changed, 1445 insertions(+), 173 deletions(-) >
