Intel QAT can be very useful for accelerating compression and encryption with supported software and where having a QAT accelerator card or found within the QAT support on recent Xeon Scalable processors. This live migration supporti s about being able to handle guest virtual machines being migrated between nodes while retaining QAT support.
The newly-queued code allows for live migration of Intel QAT Gen4 SRIOV Virtual Functions (VFs). The QAT driver can save and restore the state of a bank to which a VF is encompassed. The Intel patch series explains:
Here are the steps required to test the live migration of a QAT GEN4 VF:
1. Bind one or more QAT GEN4 VF devices to the module qat_vfio_pci.ko
2. Assign the VFs to the virtual machine and enable device live migration
3. Run a workload using a QAT VF inside the VM, for example using qatlib
4. Migrate the VM from the source node to a destination node
The patches working out the live migration support for Intel QAT are queued in cryptodev-2.6.git ahead of the Linux 6.10 merge window opening next month.