Examples provided herein relate to hot plugging PCIe cards. For example, a field programmable gate array (“FPGA”) communicably coupled to a PCIe bus may detect a new PCIe card physically connected to the PCIe bus. The FPGA may access configuration information stored by the FPGA that is associated with the PCIe bus. The FPGA may determine, based on the accessed configuration information, whether to facilitate connection of the new PCIe card to the PCIe bus. Responsive to determining that connection of the new PCIe card to the PCIe bus should be facilitated, the new PCIe card may be trained to communicate with the PCIe bus and an upstream device communicably coupled to the PCIe bus.