1. A method, comprising: performing, at a source virtualization host: determining, by a virtualization management component of the source virtualization host, that an operation to save a representation of a state of a particular virtual machine instantiated at the source virtualization host is to be implemented for a live migration of the particular virtual machine to a target virtualization host; directing a DMA (direct memory access)-capable device of the source virtualization host to generate respective DMA write records corresponding to one or more DMA write operations directed to the physical memory of the source virtualization host from the DMA-capable device; generating, by the DMA-capable device, a particular DMA write record indicating a portion of physical memory modified by a particular DMA write operation, wherein the particular DMA write record comprises at least (a) a memory address to which the particular DMA write operation is directed, and (b) a write size of the particular DMA write operation; storing, by the DMA-capable device, the particular DMA write record in a record buffer accessible from the virtualization management component, wherein the record buffer comprises one or more slots including a particular slot into which the particular DMA write record was stored by the DMA-capable device; determining, by the virtualization management component, using the record buffer, that the portion of physical memory (a) has been modified by the DMA-capable device and (b) is allocated to the particular virtual machine; initiating a copy of the portion of the physical memory modified by the DMA-capable device to a target location; providing, by the virtualization management component, an indication to the DMA-capable device that the particular DMA write record has been examined and that the particular slot is available for re-use; and re-using, by the DMA-capable device, the particular slot to store another DMA write record corresponding to a different DMA write operation.