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

[Cornelia Huck <cohuck@redhat.com>]

On Tue, 17 Oct 2017 14:17:06 +0200
Cornelia Huck <cohuck@redhat.com> wrote:

> On Mon, 16 Oct 2017 22:23:56 +0200
> David Hildenbrand <david@redhat.com> wrote:
> 
> > 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(-)
> >   
> 
> As the oom was not reproducible (and seems to be only a problem of the
> machine being run with barely enough memory), I'm inclined to queue
> this to s390-next after I got some acks/r-bs for patch 1.

And as I want to send this in my last pull req before softfreeze, I
included it anyway :)

Thanks, applied.