Virtual or Physical Machine

We are running Oracle 11g database on linux and want a high performance machine therefore we bought 128G 2xE5-2650v2 Server.
I have two options, one is to install everything like Oracle etc on the physical machine. Whereas the other option is to install Xen and create only one VM on this physical machine and allocate almost all resources to that single VM.
My question is if the performance in both the cases will be same?
I prefer Virtual machine due to its ease of maintenance/backups etc.