[v1,0/5] KVM: s390: vsie: fixes and cleanups.

Message

David Hildenbrand April 2, 2020, 6:48 p.m. UTC

Some vsie/gmap fixes and two cleanups/improvements.

Patch #1 fixes an issue reported by Janosch. It was never observed so far,
because KVM usually doesn't use a region 1 table for it's guest (unless
memory would be exceeding something like 16 EB, which isn't even supported
by the HW). Older QEMU+KVM or other hypervisors can trigger this.

Patch #2 fixes a code path that probably was never taken and will most
probably not be taken very often in the future - unless somebody really
messes up the page tables for a guest (or writes a test for it). At some
point, a test case for this would be nice.

Patch #3 fixes a rare possible race. Don't think this is stable material.

Gave it some testing with my limited access to somewhat-fast s390x
machines. Booted a Linux kernel, supplying all possible number of
page table hiearchies.

David Hildenbrand (5):
  KVM: s390: vsie: Fix region 1 ASCE sanity shadow address checks
  KVM: s390: vsie: Fix delivery of addressing exceptions
  KVM: s390: vsie: Fix possible race when shadowing region 3 tables
  KVM: s390: vsie: Move conditional reschedule
  KVM: s390: vsie: gmap_table_walk() simplifications

 arch/s390/kvm/vsie.c |  4 ++--
 arch/s390/mm/gmap.c  | 14 ++++++++++----
 2 files changed, 12 insertions(+), 6 deletions(-)