target/s390x: Store r1/r2 for page-translation exceptions during MVPG

target/s390x: Store r1/r2 for page-translation exceptions during MVPG

The PoP states:

    When EDAT-1 does not apply, and a program interruption due to a
    page-translation exception is recognized by the MOVE PAGE
    instruction, the contents of the R1 field of the instruction are
    stored in bit positions 0-3 of location 162, and the contents of
    the R2 field are stored in bit positions 4-7.

    If [...] an ASCE-type, region-first-translation,
    region-second-translation, region-third-translation, or
    segment-translation exception was recognized, the contents of
    location 162 are unpredictable.

So we have to write r1/r2 into the lowcore on page-translation
exceptions. Simply handle all exceptions inside our mvpg helper now.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Tested-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210315085449.34676-3-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>