A method for allocating resources of a host channel adapter includes the host channel adapter identifying an underlying function referenced in the first resource allocation request received from a virtual machine manager, determining that the first resource allocation request specifies a number of physical collect buffers (PCBs) allocated to the underlying function, allocating the number of PCBs to the underlying function, determining that the first resource allocation request specifies a number of virtual collect buffers (VCBs) allocated to the underlying function, and allocating the number of VCBs to the underlying function. The host channel adapter further receives command data for a command from the single virtual machine, determines that the underlying function has in use at least the number of PCBs when the command data is received, and drops the command data in the first command based on the underlying function having in use at least the number of PCBs.