From: Christian Borntraeger <borntraeger@de.ibm.com>
Date: Fri, 17 May 2013 12:41:35 +0000 (+0200)
Subject: s390/kvm: Provide a way to prevent reentering SIE
X-Git-Tag: omap-for-v3.11/fixes-for-merge-window~22^2~64
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=49b99e1e0dedbd6cc93b2d2776b60fb7151ff3d7;p=pandora-kernel.git

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>
---

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