Following support status from Metalink note 249212.1
Oracle provides support of the Oracle Stack when running on a VMware virtual machine in the following manner. If a problem arises and it is a known Oracle issue, Oracle support will recommend the appropriate solution. If that solution does not work, the issue will be referred back to VMware for support. If the problem is determined to be an unknown Oracle issue when running on a VMware virtual machine, and the issue cannot be reproduced on a physical system by Oracle support, the issue will be referred back to VMware for support. Oracle and VMware have in place a joint customer support agreement to enable customer support issues to be transferred between the two partners. In addition, all versions of RAC are not supported on VMWare by Oracle.