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

From: David Hildenbrand
Date: Thu Apr 02 2020 - 14:48:33 EST


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(-)

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2.25.1