Fix some memory issues and some hangs in vSIE.

This is still a fallout from the gmap rewrite.

v2->v3:
* Add comments to pte_needs_unshadow() and crste_needs_unshadow()
  explaining how they work
* Improve some patch descriptions

v1->v2:
* Fix potential leak of struct kvm_s390_mmu_cache in gmap_set_limit()
* Refactor and improve the checks to determine whether an unshadowing
  is needed
* Set and propagate vsie_gmem properly
* Properly mask the address passed to gmap_insert_rmap() to prevent
  creating multiple redundant rmaps when shadowing
* Clear the pgste.zero flag when needed, to prevent pages from getting
  accidentally discarded

Claudio Imbrenda (5):
  KVM: s390: vsie: Fix memory leak when unshadowing
  KVM: s390: Fix leaking kvm_s390_mmu_cache in case of errors
  KVM: s390: vsie: Fix unshadowing logic
  KVM: s390: vsie: Fix redundant rmap entries
  KVM: s390: Properly reset zero bit in PGSTE

 arch/s390/kvm/dat.c     |  1 +
 arch/s390/kvm/dat.h     |  3 +-
 arch/s390/kvm/gaccess.c |  1 +
 arch/s390/kvm/gmap.c    | 18 +++++++-----
 arch/s390/kvm/gmap.h    | 61 +++++++++++++++++++++++++++++++++++++++--
 5 files changed, 73 insertions(+), 11 deletions(-)

-- 
2.54.0