1. A method of transmitting data between storage virtualization controllers in a computer system, the storage virtualization controllers comprising a first storage virtualization controller (SVC) and a second SVC, in which the first SVC comprises a first central processing unit (CPU), a first CPU chipset, a first interface and a first memory, and the second SVC comprises a second CPU, a second CPU chipset, a second interface and a second memory, the method comprising the steps of: the first CPU of the first SVC sending a direct data transfer request to the first CPU chipset of the first SVC; the first interface in the first CPU chipset reading the direct data transfer request from a CPU interface in the first CPU chipset, in which the first interface is coupled to the second SVC through an inter-controller communication channel, and transfers the direct data transfer request to the second SVC via the inter-controller communication channel, wherein the second interface in the second interface in the second SVC receives the direct data transfer request; and the direct data transfer request comprising a virtual address obtained by converting from one of a start address and an offset address of an access destination such that the first interface recognizes, through the virtual address, the direct data transfer request, and the first interface performs direct data access to the second memory of the second SVC.