[PATCH v4 00/15] KVM: s390: Stop using page->index and other things

Claudio Imbrenda
2025-01-23T14:46:38Z

This patchseries starts moving some of the gmap logic into KVM itself,
going towards the final goal of completely removing gmap from the
non-kvm memory management code. Aside from just moving some code from
mm/gmap into kvm, this series also starts using __kvm_faultin_pfn() to
fault-in pages as needed.

But more importantly, this series removes almost all uses of
page->index (and all uses of page->lru) from the s390 KVM code.
The only remaining use is for the vsie pages, but that has already been
taken care of by David in another series.

Unfortunately the mix of hastiness and holidays means that this series
is a little bit all over the place, and not as complete as I would have
liked to.

I'm posting it now so to try to speed up the removal of page->index,
hopefully I will be able to post another short series before the
upcoming merge window closes.

v1->v2:
* moved some code around between patches to improve readability and shuffle
the order of some patches
* rebase on Sean's patchseries
* add Sean's patch to remove size limitations for internal memslots
* use Sean's new API for internal memslots to place one huge internal
memslot instead of many 4T ones for UCONTROL guests
* create new kvm/gmap-vsie.c file for VSIE code, instead of dumping
everything in the existing files, which are already too large
* improve comments and patch descriptions
* minor style and cosmetic fixes

v2->v3
* moved patch 5 back to its place
* moved uv_wiggle_folio() to mm/gmap.c and renamed it to
kvm_s390_wiggle_split_folio()
* fixed some typos
* added some lockdep asserts
* minor style fixes
* added some comments
* fixed documentation

v3->v4
* fixed some missing locks
* minor style fixes
* remove useless pt_list initialization
* fix comments
* rename gmap_shadow_pgt_lookup to shadow_pgt_lookup sinec it's static
* rename gmap_pgste_{g,s}et_index() to gmap_pgste_{g,s}et_pgt_addr()

Claudio Imbrenda (14):
KVM: s390: wrapper for KVM_BUG
KVM: s390: fake memslot for ucontrol VMs
KVM: s390: selftests: fix ucontrol memory region test
KVM: s390: move pv gmap functions into kvm
KVM: s390: use __kvm_faultin_pfn()
KVM: s390: get rid of gmap_fault()
KVM: s390: get rid of gmap_translate()
KVM: s390: move some gmap shadowing functions away from mm/gmap.c
KVM: s390: stop using page->index for non-shadow gmaps
KVM: s390: stop using lists to keep track of used dat tables
KVM: s390: move gmap_shadow_pgt_lookup() into kvm
KVM: s390: remove useless page->index usage
KVM: s390: move PGSTE softbits
KVM: s390: remove the last user of page->index

Sean Christopherson (1):
KVM: Do not restrict the size of KVM-internal memory regions

Documentation/virt/kvm/api.rst | 2 +-
arch/s390/include/asm/gmap.h | 20 +-
arch/s390/include/asm/kvm_host.h | 2 +
arch/s390/include/asm/pgtable.h | 21 +-
arch/s390/include/asm/uv.h | 6 +-
arch/s390/kernel/uv.c | 292 +-------
arch/s390/kvm/Makefile | 2 +-
arch/s390/kvm/gaccess.c | 44 +-
arch/s390/kvm/gmap-vsie.c | 139 ++++
arch/s390/kvm/gmap.c | 209 ++++++
arch/s390/kvm/gmap.h | 39 +
arch/s390/kvm/intercept.c | 5 +-
arch/s390/kvm/interrupt.c | 19 +-
arch/s390/kvm/kvm-s390.c | 224 +++++-
arch/s390/kvm/kvm-s390.h | 19 +
arch/s390/kvm/pv.c | 1 +
arch/s390/kvm/vsie.c | 2 +
arch/s390/mm/gmap.c | 681 ++++--------------
arch/s390/mm/pgalloc.c | 2 -
.../selftests/kvm/s390x/ucontrol_test.c | 8 +-
virt/kvm/kvm_main.c | 10 +-
21 files changed, 875 insertions(+), 872 deletions(-)
create mode 100644 arch/s390/kvm/gmap-vsie.c
create mode 100644 arch/s390/kvm/gmap.c
create mode 100644 arch/s390/kvm/gmap.h

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2.48.1