Your vHBAs or other PCI devices may stop running in ESXi 5.x when using Interrupt Remapping feature.

This issue only impact to UCS blade BIOS version 1.4(3c), it has been fixed on 1.4(3j).

Please refer to http://kb.vmware.com/kb/1030265 to see how to disable Interrupt Remapping feature in ESXi 5.x

Also refer to https://tools.cisco.com/bugsearch/bug/CSCty96722.