+.. _qat_kernel:
+
+Dependency on the QAT kernel driver
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+To use QAT an SRIOV-enabled QAT kernel driver is required. The VF
+devices created and initialised by this driver will be used by the QAT PMDs.
+
+Instructions for installation are below, but first an explanation of the
+relationships between the PF/VF devices and the PMDs visible to
+DPDK applications.
+
+Each QuickAssist PF device exposes a number of VF devices. Each VF device can
+enable one cryptodev PMD and/or one compressdev PMD.
+These QAT PMDs share the same underlying device and pci-mgmt code, but are
+enumerated independently on their respective APIs and appear as independent
+devices to applications.
+
+.. Note::
+
+ Each VF can only be used by one DPDK process. It is not possible to share
+ the same VF across multiple processes, even if these processes are using
+ different acceleration services.
+
+ Conversely one DPDK process can use one or more QAT VFs and can expose both
+ cryptodev and compressdev instances on each of those VFs.
+