4. Intel(R) QuickAssist (QAT) Compression Poll Mode Driver
The QAT compression PMD provides poll mode compression & decompression driver support for the following hardware accelerator devices:
Intel QuickAssist Technology C62x
Intel QuickAssist Technology C3xxx
Intel QuickAssist Technology DH895x
4.1. Features
QAT compression PMD has support for:
Compression/Decompression algorithm:
- DEFLATE - using Fixed and Dynamic Huffman encoding
Window size support:
- 32K
Checksum generation:
- CRC32, Adler and combined checksum
Stateful operation:
- Decompression only
4.2. Limitations
- Compressdev level 0, no compression, is not supported.
- Queue-pairs are thread-safe on Intel CPUs but Queues are not (that is, within a single queue-pair all enqueues to the TX queue must be done from one thread and all dequeues from the RX queue must be done from one thread, but enqueues and dequeues may be done in different threads.)
- No BSD support as BSD QAT kernel driver not available.
- When using Deflate dynamic huffman encoding for compression, the input size (op.src.length) must be < CONFIG_RTE_PMD_QAT_COMP_IM_BUFFER_SIZE from the config file, see Build Configuration for more details.
- Stateful compression is not supported.
4.3. Installation
The QAT compression PMD is built by default with a standard DPDK build.
It depends on a QAT kernel driver, see Building PMDs on QAT.