Migration of virtual machines

A method of migrating a virtual machine from a source processing platform to a destination processing platform, comprising:

• causing, by management circuitry, a migration of the virtual machine from the source processing platform to the destination processing platform, so that a future execution of program instructions associated with the virtual machine are executed by destination processing circuitry of the destination processing platform instead of source processing circuitry of the source processing platform, wherein the migration causes a number of data pages belonging to the virtual machine to be migrated from a source memory device of the source processing platform to a destination memory device of the destination processing platform;
• employing a plurality of migration streams to perform the migration, where each migration stream is allocated an associated memory region that is mutually exclusive to a memory region allocated to any other migration stream in the plurality of migration streams, and each migration stream is used to migrate data pages within its associated memory region;
• and
• checking, by integrity checking circuitry, integrity of the virtual machine during the migration with reference to tracking information maintained to indicate progress of the migration, the checking comprising using the tracking information to assess whether a set of integrity checking rules are satisfied, and to prevent the migration proceeding to a phase where program instructions of the virtual machine are permitted to be executed by the destination processing circuitry unless the set of integrity checking rules are satisfied, wherein the set of integrity checking rules are determined taking into account that any given data page is constrained to be migrated using the migration stream whose associated memory region contains the given data page.

A computer readable medium comprising a computer program configured, when executed by a computer, to:

• provide a plurality of migration streams for use in performing a migration of a virtual machine from a source processing platform to a destination processing platform, so that a future execution of program instructions associated with the virtual machine are executed by destination processing circuitry of the destination processing platform instead of source processing circuitry of the source processing platform, the migration comprising transfer of a number of data pages belonging to the virtual machine from a source memory device of the source processing platform to a destination memory device of the destination processing platform;
• allocate each migration stream an associated memory region that is mutually exclusive to a memory region allocated to any other migration stream in the plurality of migration streams, such that each migration stream is used to migrate data pages within its associated memory region;
• use tracking information indicating progress of the migration to assess whether a set of integrity checking rules are satisfied;
• and
• prevent the migration proceeding to a phase where program instructions of the virtual machine are permitted to be executed by the destination processing circuitry unless the set of integrity checking rules are satisfied;
• wherein the set of integrity checking rules are determined taking into account that any given data page is constrained to be migrated using the migration stream whose associated memory region contains the given data page.