A method maintaining a fixed QoS for a PCIe device accessed by multiple hosts includes; receiving commands from the hosts in PCIe function queues of the PCIe device, fetching the commands from the PCIe function command queues, queuing the commands according to a command arbitration policy established for the PCIe device, storing the queued commands in an internal memory of the PCIe device, retrieving the queued commands from the internal memory in a sequence determined by applying a calculated QoS to at least one of the queued commands, and allocating PCIe device resources based on payload information corresponding to each one of the retrieved commands.