Rdma-based state transfer in virtual machine live migration

A method, comprising:

• determining, by a processor of a first computer system, that a plurality of memory blocks have been modified by a virtual machine undergoing live migration from the first computer system to a second computer system;
• selecting, asynchronously with respect to the determining, a first memory block of the plurality of memory blocks;
• registering the first memory block with an RDMA adapter for transfer to the second computer system;
• transmitting the first memory block to the second computer system via the RDMA adapter;
• responsive to transmitting the first memory block, selecting a second memory block of the plurality of memory blocks;
• registering the second memory block with an RDMA adapter for transfer to the second computer system;
• and
• transmitting the second memory block to the second computer system via the RDMA adapter;
• wherein registering a memory block with the RDMA adapter comprises pinning the memory block and wherein an amount of pinned physical memory in the first computer system does not exceed a pre-defined value.

A system of a first computer system, comprising:

• a memory;
• a remote direct memory access (RDMA) adapter coupled to the memory;
• and
• a processor, coupled to the memory, to:
• determine that a memory block has been modified by a virtual machine undergoing live migration from the first computer system to a second computer system;
• designate the modified memory block for transfer via a remote direct memory access (RDMA) adapter to the second computer system;
• select, asynchronously with respect to the designating, a memory block from a plurality of memory blocks designated for RDMA transfer to the second computer system, wherein a sum of an amount of pinned physical memory in the first computer system and a size of the selected memory block does not exceed a pre-defined value;
• register the selected memory block with the RDMA adapter;
• and
• transmit the selected memory block to the second computer system via the RDMA adapter.

A computer-readable non-transitory storage medium comprising executable instructions that, when executed by a processor, cause the processor to:

• determine, by the processor, that a memory block has been modified by a virtual machine undergoing live migration from a first computer system to a second computer system;
• designate the modified memory block for transfer via a remote direct memory access (RDMA) adapter to the second computer system;
• select, asynchronously with respect to the designating, a memory block from a plurality of memory blocks designated for RDMA transfer to the second computer system, wherein a sum of an amount of pinned physical memory in the first computer system and a size of the selected memory block does not exceed a pre-defined value;
• register the selected memory block with the RDMA adapter;
• and
• transmit the selected memory block to the second computer system via the RDMA adapter.