KVM: s390: Handle hosts not supporting s390-virtio.
authorCornelia Huck <cornelia.huck@de.ibm.com>
Fri, 14 Dec 2012 16:02:16 +0000 (17:02 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 28 Feb 2013 14:59:01 +0000 (06:59 -0800)
commit2030511afec79a7f65b967c3d8a22e4a1edd9532
treeeaa759f8f957a089596c01ef09ebdfc71b4340ec
parent7fecb64cca9a98f60ff4bc794bb353512bd5c665
KVM: s390: Handle hosts not supporting s390-virtio.

commit 55c171a6d90dc0574021f9c836127cfd1a7d2e30 upstream.

Running under a kvm host does not necessarily imply the presence of
a page mapped above the main memory with the virtio information;
however, the code includes a hard coded access to that page.

Instead, check for the presence of the page and exit gracefully
before we hit an addressing exception if it does not exist.

Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/s390/kvm/kvm_virtio.c