KVM: s390: pv: Add query interface

KVM: s390: pv: Add query interface

Some of the query information is already available via sysfs but
having a IOCTL makes the information easier to retrieve.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Link: https://lore.kernel.org/r/20220517163629.3443-4-frankja@linux.ibm.com
Message-Id: <20220517163629.3443-4-frankja@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>