1. A method for caching I/O data in a solid state drive (SSD) locally attached to a host computer supporting the running of a virtual machine (VM), the method comprising: allocating portions of the SSD to use as cache storage for VMs running on the host computer; maintaining, by a hypervisor of the host computer, a mapping relationship between unique identifiers for VMs running on the host computer and one or more process identifiers (PIDs) associated with processes running in the host computer that correspond to each of the VM's execution on the host computer; integrating a cache module into an I/O stack of the hypervisor to allow the cache module to intercept I/O requests before the I/O requests are forwarded to a virtual disk file; receiving, by the hypervisor, an I/O request from the VM, wherein the VM directed the I/O request for the virtual disk file of the VM that is remotely stored from the host computer; intercepting, by the cache module in the hypervisor, the I/O request from the I/O stack of the hypervisor before the I/O request is sent to the virtual disk file; determining, by the cache module in the hypervisor, a PID associated with I/O request prior to accessing the mapping relationship; using, by the cache module in the hypervisor, the determined PID to look up and extract a unique identifier for the VM that corresponds to the determined PID from the mapping relationship; and accessing, by the cache module in the hypervisor, a portion of the SSD corresponding to the unique identifier of the VM that is used as a cache for the VM in order to handle the I/O request.