tree 204052379d35e6459207571b3e2bb1d460e2cef2
parent 95d38fd0bcf1996082f5f8762e6f1c849755e0c6
author Christian Borntraeger <borntraeger@de.ibm.com> 1368794495 +0200
committer Gleb Natapov <gleb@redhat.com> 1369126523 +0300

s390/kvm: Provide a way to prevent reentering SIE

Lets provide functions to prevent KVM from reentering SIE and
to kick cpus out of SIE. We cannot use the common kvm_vcpu_kick code,
since we need to kick out guests in places that hold architecture
specific locks (e.g. pgste lock) which might be necessary on the
other cpus - so no waiting possible.

So lets provide a bit in a private field of the sie control block
that acts as a gate keeper, after we claimed we are in SIE.
Please note that we do not reuse prog0c, since we want to access
that bit without atomic ops.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>