What model of CEC? If it's a z10 or a z196, it might be some of the power-saving features kicking in. That message can also occur if capacity-on-demand has modified the system capability (although it's usually rare to see it on a IFL).
From: The IBM z/VM Operating System [mailto:IBMVM@LISTSERV.UARK.EDU] On Behalf Of Bhemidhi, Ashwin Sent: Tuesday, April 19, 2011 2:56 PM To: IBMVM@LISTSERV.UARK.EDU Subject: sclp_config: cpu capability changed. Hello all , I have noticed kernel message "Apr 19 12:35:07 <hostname> kernel: sclp_config: cpu capability changed" on all of our Linux guest on multiple LPARs. Does this indicate a hardware issue with the IFL processor? I have asked our hardware support to check for any error on the machine. Thank you, Ashwin Bhemidhi