Multiple queue pair access with single doorbell

A network interface adapter, for coupling a host device to a communication network, the adapter comprising:

• a range of doorbell addresses in an address space of the host device, such that each of a plurality of processes running on the host device is assigned a respective doorbell address within the range;
• and
• a controller, which is arranged to allocate a plurality of instances of a communication service provided by the adapter on the network to at least some of the processes on the host device, such that each of the instances is allocated to a particular one of the processes, and which is further arranged, when the adapter receives a request submitted by a given one of the processes to its respective doorbell address to access one of the allocated service instances specified in the request, to verify, based on the doorbell address to which the request was submitted, that the specified instance was allocated to the given process before allowing the adapter, in response to the request, to convey data over the network using the specified instance of the service.

A channel adapter for coupling a host device to a communication network, the adapter comprising:

• a plurality of pairs of work queues, for allocation to a process on the host device for use in sending and receiving communications over the network;
• and
• a single doorbell address in an address space of the host device, for assignment to the process for use in accessing any of the plurality of the pairs of work queues, so that in response to a work request submitted by the process to the single doorbell address to place a work item in one of the allocated queues that is specified in the request, data are transported over the network by the adapter.