[Qemu-devel] [PATCH v1 0/2] s390x/tcg: LAP support using immediate TLB invalidation

[David Hildenbrand <david@redhat.com>]

Details about Low-Address Protection can be found in description of
patch 1 and 2. It is basically a subpage protection of the first two
pages of every address space (for which it is enabled).

We can achieve this by simply directly invalidating the TLB entry and
therefore forcing every write accesses onto these two pages into the slow
path.

With this patch, I can boot Linux just fine (which uses LAP). This also
makes all related kvm-unit-tests that we have pass.


RFC -> v1:
- fix LAP range check (Thomas)
- SIGP fix got picked up

Based on: https://github.com/cohuck/qemu.git s390-next
Available on: https://github.com/dhildenb/qemu.git s390x_lap


David Hildenbrand (2):
  accel/tcg: allow to invalidate a write TLB entry immediately
  s390x/tcg: low-address protection support

 accel/tcg/cputlb.c           |  5 ++-
 accel/tcg/softmmu_template.h |  4 +-
 include/exec/cpu-all.h       |  3 ++
 target/s390x/excp_helper.c   |  3 +-
 target/s390x/mem_helper.c    |  8 ----
 target/s390x/mmu_helper.c    | 94 +++++++++++++++++++++++++++-----------------
 6 files changed, 69 insertions(+), 48 deletions(-)

-- 
2.13.5