Abstract: An apparatus, method and computer program are described, the apparatus comprising processing circuitry configured to execute software, and an interface configured to receive, from the processing circuitry, a configuration request from first software requesting configuration of a virtualised device. In response to the configuration request, the interface is configured to forward a mediated request to the processing circuitry, and the mediated request comprises a request that second software having a higher privilege level than the first software determines a response to the configuration request received from the first software.

Abstract: A data processing system and method of data processing are provided. The system comprises first and second data processing agents and data storage shared coherently between the both data processing agents to store a message data structure to provide a message channel between them. A further data storage is accessible to both data processing agents to store message channel metadata, which provides message status information for the message channel. The message channel metadata is one of a plurality of message channel metadata types defined for a corresponding plurality of message channel types between the first and second data processing agents, and at least one of the first and second data processing agents is responsive to an initialization trigger to establish the message channel with a selected message channel type.

Abstract: A data processing system and a method of data processing are provided. The system comprises a first data processing agent, a second data processing agent, and a third data processing agent. Each of the second and third data processing agents have access to one or more caches. A messaging mechanism conveys a message from the first data processing agent to one of the second and third data processing agents specified as a message destination agent in the message. A stashing manager monitors the messaging mechanism and selectively causes data associated with the message to be cached for access by the message destination agent in a cache of the one or more caches in dependence on at least one parameter associated with the message and at least one stashing control parameter defined for a link from the first data processing agent to the message destination agent.

Abstract: An apparatus, method and computer program are described, the apparatus comprising processing circuitry configured to execute software, and an interface configured to receive, from the processing circuitry, a configuration request from first software requesting configuration of a virtualised device. In response to the configuration request, the interface is configured to forward a mediated request to the processing circuitry, and the mediated request comprises a request that second software having a higher privilege level than the first software determines a response to the configuration request received from the first software.

Abstract: A data processing system and a method of data processing are provided. The system comprises a first data processing agent, a second data processing agent, and a third data processing agent. Each of the second and third data processing agents have access to one or more caches. A messaging mechanism conveys a message from the first data processing agent to one of the second and third data processing agents specified as a message destination agent in the message. A stashing manager monitors the messaging mechanism and selectively causes data associated with the message to be cached for access by the message destination agent in a cache of the one or more caches in dependence on at least one parameter associated with the message and at least one stashing control parameter defined for a link from the first data processing agent to the message destination agent.

Abstract: Apparatus and a corresponding method for processing received datagram fragments are provided. Fragments are considered in fragments lists, which comprise a linked list of fragments. The fragments lists are referenced by corresponding entries stored in fragment list storage, where all received fragments from a given datagram will form part of the same fragment list, but a given fragment list can comprise fragments from multiple datagrams. An accumulated size of the payloads for a linked list of fragments is maintained and allows a determination to be made of whether it appears that sufficient fragments have been received that reassembly of a datagram may be possible. Access to a selected fragment list entry is made atomically, wherein the existing entry is first read and then if a datagram reassembly is to be attempted a write access sets the selected fragment list entry to a null entry before that datagram reassembly is attempted.

Abstract: Apparatus and a corresponding method for processing received datagram fragments are provided. Fragments are considered in fragments lists, which comprise a linked list of fragments. The fragments lists are referenced by corresponding entries stored in fragment list storage, where all received fragments from a given datagram will form part of the same fragment list, but a given fragment list can comprise fragments from multiple datagrams. An accumulated size of the payloads for a linked list of fragments is maintained and allows a determination to be made of whether it appears that sufficient fragments have been received that reassembly of a datagram may be possible. Access to a selected fragment list entry is made atomically, wherein the existing entry is first read and then if a datagram reassembly is to be attempted a write access sets the selected fragment list entry to a null entry before that datagram reassembly is attempted.