Linux 6.7 Will Allow More Efficient Use With Intel QAT Gen4 Hardware

With the Linux 6.7 kernel this winter there is a new feature coming to Intel's QuickAssist Technology (QAT) device driver that will allow more efficient use with QAT Gen4 hardware such as the latest-generation Intel Xeon Scalable "Sapphire Rapids" processors.

Intel QAT Gen4 devices -- so far to appear with select Sapphire Rapids processors as one of the accelerator options -- support the notion of chained compression "DC" operations. With a single firmware request the chained operations allow for hashing and then compressing the data in one-go.

The Intel QAT Linux kernel driver is being extended to enable the DC chaining service with the latest QAT accelerators. By allowing the single DCC request to hash and then immediately compress the data it saves some overhead and the latency involved in making multiple requests to the QAT hardware.

More details on the QAT DC chaining can be found via this patch enabling the support in the open-source kernel driver. That patch is now queued into the "cryptodev" development tree of the cryptographic subsystem updates for the Linux 6.7 merge window that will open up in November.