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Diffstat (limited to 'doc/guides/cryptodevs/qat.rst')
| -rw-r--r-- | doc/guides/cryptodevs/qat.rst | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/doc/guides/cryptodevs/qat.rst b/doc/guides/cryptodevs/qat.rst index b2dfeb00..1db98685 100644 --- a/doc/guides/cryptodevs/qat.rst +++ b/doc/guides/cryptodevs/qat.rst @@ -156,6 +156,7 @@ These are the build configuration options affecting QAT, and their default value CONFIG_RTE_LIBRTE_PMD_QAT_SYM=n CONFIG_RTE_PMD_QAT_MAX_PCI_DEVICES=48 CONFIG_RTE_PMD_QAT_COMP_SGL_MAX_SEGMENTS=16 + CONFIG_RTE_PMD_QAT_COMP_IM_BUFFER_SIZE=65536 CONFIG_RTE_LIBRTE_PMD_QAT must be enabled for any QAT PMD to be built. @@ -168,14 +169,30 @@ options and is built by default. The number of VFs per PF varies - see table below. If multiple QAT packages are installed on a platform then CONFIG_RTE_PMD_QAT_MAX_PCI_DEVICES should be adjusted to the number of VFs which the QAT common code will need to handle. -Note, there is a separate config item for max cryptodevs CONFIG_RTE_CRYPTO_MAX_DEVS, -if necessary this should be adjusted to handle the total of QAT and other devices -which the process will use. +Note, there are separate config items for max cryptodevs CONFIG_RTE_CRYPTO_MAX_DEVS +and max compressdevs CONFIG_RTE_COMPRESS_MAX_DEVS, if necessary these should be +adjusted to handle the total of QAT and other devices which the process will use. QAT allocates internal structures to handle SGLs. For the compression service CONFIG_RTE_PMD_QAT_COMP_SGL_MAX_SEGMENTS can be changed if more segments are needed. An extra (max_inflight_ops x 16) bytes per queue_pair will be used for every increment. +QAT compression PMD needs intermediate buffers to support Deflate compression +with Dynamic Huffman encoding. CONFIG_RTE_PMD_QAT_COMP_IM_BUFFER_SIZE +specifies the size of a single buffer, the PMD will allocate a multiple of these, +plus some extra space for associated meta-data. For GEN2 devices, 20 buffers plus +1472 bytes are allocated. + +.. Note:: + + If the compressed output of a Deflate operation using Dynamic Huffman + Encoding is too big to fit in an intermediate buffer, then the + operation will return RTE_COMP_OP_STATUS_ERROR and an error will be + displayed. Options for the application in this case + are to split the input data into smaller chunks and resubmit + in multiple operations or to configure QAT with + larger intermediate buffers. + Device and driver naming ~~~~~~~~~~~~~~~~~~~~~~~~ |