1. A computer implemented method for delivering a software payload to a virtual machine that comprises: delivering a software payload to guest software on the virtual machine so that the software payload is part of a file system accessible by the guest software, including delivering the software payload to the guest software through an input/output (I/O) port that is a backdoor software communication pipe, wherein delivering does not involve any virtual network interface card (NIC) or any virtual host bus adapter (VHBA) of the virtual machine, and determining an infrastructure configuration type of the virtual machine, wherein delivering the software payload to the guest software through the backdoor software communication pipe comprises at least one of: for a 2-copy infrastructure configuration type of the virtual machine, performing a 2-copy operation comprising copying the software payload to a cache and transferring contents of the software payload to the guest software through the backdoor software communication pipe once the cache holds a copy of the software payload; for a 1-copy infrastructure configuration type of the virtual machine, performing a 1-copy operation comprising copying the software payload directly from a file system, which is visible to the guest software, through the backdoor software communication pipe to the guest software; and for a 0-copy infrastructure configuration type of the virtual machine, performing a 0-copy operation comprising creating a virtual file system within the guest software, mapping the virtual file system to a file repository that holds the software payload, and accessing the software payload held in the file repository through the backdoor software communication pipe; processing the software payload within the virtual machine; establishing a data path from the software payload to the virtual machine and a guest agent of the virtual machine; after communicating to the guest agent, waiting for reception of a status from the guest agent; and after reception of the status, deactivating the data path.