crypto: iaa - Add IAA Compression Accelerator Documentation
Because the IAA Compression Accelerator requires significant user setup in order to be used properly, this adds documentation on the iaa_crypto driver including setup, usage, and examples. Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Tom Zanussi
Herbert Xu
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Documentation/driver-api/crypto/iaa/iaa-crypto.rst
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Documentation/driver-api/crypto/iaa/iaa-crypto.rst
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.. SPDX-License-Identifier: GPL-2.0
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=========================================
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IAA Compression Accelerator Crypto Driver
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=========================================
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Tom Zanussi <tom.zanussi@linux.intel.com>
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The IAA crypto driver supports compression/decompression compatible
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with the DEFLATE compression standard described in RFC 1951, which is
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the compression/decompression algorithm exported by this module.
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The IAA hardware spec can be found here:
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https://cdrdv2.intel.com/v1/dl/getContent/721858
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The iaa_crypto driver is designed to work as a layer underneath
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higher-level compression devices such as zswap.
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Users can select IAA compress/decompress acceleration by specifying
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one of the supported IAA compression algorithms in whatever facility
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allows compression algorithms to be selected.
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For example, a zswap device can select the IAA 'fixed' mode
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represented by selecting the 'deflate-iaa' crypto compression
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algorithm::
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# echo deflate-iaa > /sys/module/zswap/parameters/compressor
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This will tell zswap to use the IAA 'fixed' compression mode for all
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compresses and decompresses.
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Currently, there is only one compression modes available, 'fixed'
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mode.
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The 'fixed' compression mode implements the compression scheme
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specified by RFC 1951 and is given the crypto algorithm name
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'deflate-iaa'. (Because the IAA hardware has a 4k history-window
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limitation, only buffers <= 4k, or that have been compressed using a
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<= 4k history window, are technically compliant with the deflate spec,
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which allows for a window of up to 32k. Because of this limitation,
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the IAA fixed mode deflate algorithm is given its own algorithm name
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rather than simply 'deflate').
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Config options and other setup
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==============================
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The IAA crypto driver is available via menuconfig using the following
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path::
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Cryptographic API -> Hardware crypto devices -> Support for Intel(R) IAA Compression Accelerator
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In the configuration file the option called CONFIG_CRYPTO_DEV_IAA_CRYPTO.
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The IAA crypto driver also supports statistics, which are available
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via menuconfig using the following path::
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Cryptographic API -> Hardware crypto devices -> Support for Intel(R) IAA Compression -> Enable Intel(R) IAA Compression Accelerator Statistics
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In the configuration file the option called CONFIG_CRYPTO_DEV_IAA_CRYPTO_STATS.
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The following config options should also be enabled::
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CONFIG_IRQ_REMAP=y
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CONFIG_INTEL_IOMMU=y
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CONFIG_INTEL_IOMMU_SVM=y
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CONFIG_PCI_ATS=y
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CONFIG_PCI_PRI=y
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CONFIG_PCI_PASID=y
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CONFIG_INTEL_IDXD=m
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CONFIG_INTEL_IDXD_SVM=y
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IAA is one of the first Intel accelerator IPs that can work in
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conjunction with the Intel IOMMU. There are multiple modes that exist
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for testing. Based on IOMMU configuration, there are 3 modes::
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- Scalable
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- Legacy
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- No IOMMU
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Scalable mode
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-------------
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Scalable mode supports Shared Virtual Memory (SVM or SVA). It is
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entered when using the kernel boot commandline::
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intel_iommu=on,sm_on
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with VT-d turned on in BIOS.
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With scalable mode, both shared and dedicated workqueues are available
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for use.
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For scalable mode, the following BIOS settings should be enabled::
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Socket Configuration > IIO Configuration > Intel VT for Directed I/O (VT-d) > Intel VT for Directed I/O
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Socket Configuration > IIO Configuration > PCIe ENQCMD > ENQCMDS
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Legacy mode
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-----------
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Legacy mode is entered when using the kernel boot commandline::
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intel_iommu=off
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or VT-d is not turned on in BIOS.
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If you have booted into Linux and not sure if VT-d is on, do a "dmesg
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| grep -i dmar". If you don't see a number of DMAR devices enumerated,
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most likely VT-d is not on.
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With legacy mode, only dedicated workqueues are available for use.
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No IOMMU mode
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-------------
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No IOMMU mode is entered when using the kernel boot commandline::
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iommu=off.
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With no IOMMU mode, only dedicated workqueues are available for use.
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Usage
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=====
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accel-config
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------------
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When loaded, the iaa_crypto driver automatically creates a default
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configuration and enables it, and assigns default driver attributes.
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If a different configuration or set of driver attributes is required,
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the user must first disable the IAA devices and workqueues, reset the
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configuration, and then re-register the deflate-iaa algorithm with the
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crypto subsystem by removing and reinserting the iaa_crypto module.
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The :ref:`iaa_disable_script` in the 'Use Cases'
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section below can be used to disable the default configuration.
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See :ref:`iaa_default_config` below for details of the default
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configuration.
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More likely than not, however, and because of the complexity and
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configurability of the accelerator devices, the user will want to
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configure the device and manually enable the desired devices and
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workqueues.
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The userspace tool to help doing that is called accel-config. Using
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accel-config to configure device or loading a previously saved config
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is highly recommended. The device can be controlled via sysfs
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directly but comes with the warning that you should do this ONLY if
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you know exactly what you are doing. The following sections will not
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cover the sysfs interface but assumes you will be using accel-config.
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The :ref:`iaa_sysfs_config` section in the appendix below can be
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consulted for the sysfs interface details if interested.
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The accel-config tool along with instructions for building it can be
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found here:
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https://github.com/intel/idxd-config/#readme
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Typical usage
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-------------
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In order for the iaa_crypto module to actually do any
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compression/decompression work on behalf of a facility, one or more
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IAA workqueues need to be bound to the iaa_crypto driver.
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For instance, here's an example of configuring an IAA workqueue and
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binding it to the iaa_crypto driver (note that device names are
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specified as 'iax' rather than 'iaa' - this is because upstream still
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has the old 'iax' device naming in place) ::
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# configure wq1.0
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accel-config config-wq --group-id=0 --mode=dedicated --type=kernel --name="iaa_crypto" --device_name="crypto" iax1/wq1.0
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# enable IAA device iax1
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accel-config enable-device iax1
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# enable wq1.0 on IAX device iax1
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accel-config enable-wq iax1/wq1.0
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Whenever a new workqueue is bound to or unbound from the iaa_crypto
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driver, the available workqueues are 'rebalanced' such that work
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submitted from a particular CPU is given to the most appropriate
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workqueue available. Current best practice is to configure and bind
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at least one workqueue for each IAA device, but as long as there is at
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least one workqueue configured and bound to any IAA device in the
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system, the iaa_crypto driver will work, albeit most likely not as
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efficiently.
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The IAA crypto algorigthms is operational and compression and
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decompression operations are fully enabled following the successful
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binding of the first IAA workqueue to the iaa_crypto driver.
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Similarly, the IAA crypto algorithm is not operational and compression
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and decompression operations are disabled following the unbinding of
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the last IAA worqueue to the iaa_crypto driver.
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As a result, the IAA crypto algorithms and thus the IAA hardware are
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only available when one or more workques are bound to the iaa_crypto
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driver.
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When there are no IAA workqueues bound to the driver, the IAA crypto
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algorithms can be unregistered by removing the module.
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Driver attributes
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-----------------
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There are a couple user-configurable driver attributes that can be
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used to configure various modes of operation. They're listed below,
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along with their default values. To set any of these attributes, echo
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the appropriate values to the attribute file located under
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/sys/bus/dsa/drivers/crypto/
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The attribute settings at the time the IAA algorithms are registered
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are captured in each algorithm's crypto_ctx and used for all compresses
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and decompresses when using that algorithm.
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The available attributes are:
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- verify_compress
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Toggle compression verification. If set, each compress will be
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internally decompressed and the contents verified, returning error
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codes if unsuccessful. This can be toggled with 0/1::
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echo 0 > /sys/bus/dsa/drivers/crypto/verify_compress
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The default setting is '1' - verify all compresses.
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- sync_mode
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Select mode to be used to wait for completion of each compresses
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and decompress operation.
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The crypto async interface support implemented by iaa_crypto
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provides an implementation that satisfies the interface but does
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so in a synchronous manner - it fills and submits the IDXD
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descriptor and then loops around waiting for it to complete before
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returning. This isn't a problem at the moment, since all existing
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callers (e.g. zswap) wrap any asynchronous callees in a
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synchronous wrapper anyway.
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The iaa_crypto driver does however provide true asynchronous
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support for callers that can make use of it. In this mode, it
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fills and submits the IDXD descriptor, then returns immediately
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with -EINPROGRESS. The caller can then either poll for completion
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itself, which requires specific code in the caller which currently
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nothing in the upstream kernel implements, or go to sleep and wait
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for an interrupt signaling completion. This latter mode is
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supported by current users in the kernel such as zswap via
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synchronous wrappers. Although it is supported this mode is
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significantly slower than the synchronous mode that does the
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polling in the iaa_crypto driver previously mentioned.
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This mode can be enabled by writing 'async_irq' to the sync_mode
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iaa_crypto driver attribute::
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echo async_irq > /sys/bus/dsa/drivers/crypto/sync_mode
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Async mode without interrupts (caller must poll) can be enabled by
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writing 'async' to it::
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echo async > /sys/bus/dsa/drivers/crypto/sync_mode
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The mode that does the polling in the iaa_crypto driver can be
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enabled by writing 'sync' to it::
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echo sync > /sys/bus/dsa/drivers/crypto/sync_mode
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The default mode is 'sync'.
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.. _iaa_default_config:
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IAA Default Configuration
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-------------------------
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When the iaa_crypto driver is loaded, each IAA device has a single
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work queue configured for it, with the following attributes::
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mode "dedicated"
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threshold 0
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size Total WQ Size from WQCAP
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priority 10
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type IDXD_WQT_KERNEL
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group 0
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name "iaa_crypto"
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driver_name "crypto"
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The devices and workqueues are also enabled and therefore the driver
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is ready to be used without any additional configuration.
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The default driver attributes in effect when the driver is loaded are::
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sync_mode "sync"
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verify_compress 1
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In order to change either the device/work queue or driver attributes,
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the enabled devices and workqueues must first be disabled. In order
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to have the new configuration applied to the deflate-iaa crypto
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algorithm, it needs to be re-registered by removing and reinserting
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the iaa_crypto module. The :ref:`iaa_disable_script` in the 'Use
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Cases' section below can be used to disable the default configuration.
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Statistics
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==========
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If the optional debugfs statistics support is enabled, the IAA crypto
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driver will generate statistics which can be accessed in debugfs at::
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# ls -al /sys/kernel/debug/iaa-crypto/
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total 0
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drwxr-xr-x 2 root root 0 Mar 3 09:35 .
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drwx------ 47 root root 0 Mar 3 09:35 ..
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-rw-r--r-- 1 root root 0 Mar 3 09:35 max_acomp_delay_ns
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-rw-r--r-- 1 root root 0 Mar 3 09:35 max_adecomp_delay_ns
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-rw-r--r-- 1 root root 0 Mar 3 09:35 max_comp_delay_ns
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-rw-r--r-- 1 root root 0 Mar 3 09:35 max_decomp_delay_ns
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-rw-r--r-- 1 root root 0 Mar 3 09:35 stats_reset
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-rw-r--r-- 1 root root 0 Mar 3 09:35 total_comp_bytes_out
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-rw-r--r-- 1 root root 0 Mar 3 09:35 total_comp_calls
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-rw-r--r-- 1 root root 0 Mar 3 09:35 total_decomp_bytes_in
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-rw-r--r-- 1 root root 0 Mar 3 09:35 total_decomp_calls
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-rw-r--r-- 1 root root 0 Mar 3 09:35 wq_stats
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Most of the above statisticss are self-explanatory. The wq_stats file
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shows per-wq stats, a set for each iaa device and wq in addition to
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some global stats::
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# cat wq_stats
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global stats:
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total_comp_calls: 100
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total_decomp_calls: 100
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total_comp_bytes_out: 22800
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total_decomp_bytes_in: 22800
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total_completion_einval_errors: 0
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total_completion_timeout_errors: 0
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total_completion_comp_buf_overflow_errors: 0
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iaa device:
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id: 1
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n_wqs: 1
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comp_calls: 0
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comp_bytes: 0
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decomp_calls: 0
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decomp_bytes: 0
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wqs:
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name: iaa_crypto
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comp_calls: 0
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comp_bytes: 0
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decomp_calls: 0
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decomp_bytes: 0
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iaa device:
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id: 3
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n_wqs: 1
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comp_calls: 0
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comp_bytes: 0
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decomp_calls: 0
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decomp_bytes: 0
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wqs:
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name: iaa_crypto
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comp_calls: 0
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comp_bytes: 0
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decomp_calls: 0
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decomp_bytes: 0
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iaa device:
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id: 5
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n_wqs: 1
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comp_calls: 100
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comp_bytes: 22800
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decomp_calls: 100
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decomp_bytes: 22800
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wqs:
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name: iaa_crypto
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comp_calls: 100
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comp_bytes: 22800
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decomp_calls: 100
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decomp_bytes: 22800
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Writing 0 to 'stats_reset' resets all the stats, including the
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per-device and per-wq stats::
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# echo 0 > stats_reset
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# cat wq_stats
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global stats:
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total_comp_calls: 0
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total_decomp_calls: 0
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total_comp_bytes_out: 0
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total_decomp_bytes_in: 0
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total_completion_einval_errors: 0
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total_completion_timeout_errors: 0
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total_completion_comp_buf_overflow_errors: 0
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...
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Use cases
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=========
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Simple zswap test
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-----------------
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For this example, the kernel should be configured according to the
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dedicated mode options described above, and zswap should be enabled as
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well::
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CONFIG_ZSWAP=y
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This is a simple test that uses iaa_compress as the compressor for a
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swap (zswap) device. It sets up the zswap device and then uses the
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memory_memadvise program listed below to forcibly swap out and in a
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specified number of pages, demonstrating both compress and decompress.
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The zswap test expects the work queues for each IAA device on the
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system to be configured properly as a kernel workqueue with a
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workqueue driver_name of "crypto".
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The first step is to make sure the iaa_crypto module is loaded::
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modprobe iaa_crypto
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If the IAA devices and workqueues haven't previously been disabled and
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reconfigured, then the default configuration should be in place and no
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further IAA configuration is necessary. See :ref:`iaa_default_config`
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below for details of the default configuration.
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If the default configuration is in place, you should see the iaa
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devices and wq0s enabled::
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# cat /sys/bus/dsa/devices/iax1/state
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enabled
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# cat /sys/bus/dsa/devices/iax1/wq1.0/state
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enabled
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To demonstrate that the following steps work as expected, these
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commands can be used to enable debug output::
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# echo -n 'module iaa_crypto +p' > /sys/kernel/debug/dynamic_debug/control
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# echo -n 'module idxd +p' > /sys/kernel/debug/dynamic_debug/control
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Use the following commands to enable zswap::
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# echo 0 > /sys/module/zswap/parameters/enabled
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# echo 50 > /sys/module/zswap/parameters/max_pool_percent
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# echo deflate-iaa > /sys/module/zswap/parameters/compressor
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# echo zsmalloc > /sys/module/zswap/parameters/zpool
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# echo 1 > /sys/module/zswap/parameters/enabled
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# echo 0 > /sys/module/zswap/parameters/same_filled_pages_enabled
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# echo 100 > /proc/sys/vm/swappiness
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# echo never > /sys/kernel/mm/transparent_hugepage/enabled
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# echo 1 > /proc/sys/vm/overcommit_memory
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Now you can now run the zswap workload you want to measure. For
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example, using the memory_memadvise code below, the following command
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will swap in and out 100 pages::
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./memory_madvise 100
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Allocating 100 pages to swap in/out
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Swapping out 100 pages
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Swapping in 100 pages
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Swapped out and in 100 pages
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You should see something like the following in the dmesg output::
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|
||||
[ 404.202972] idxd 0000:e7:02.0: iaa_comp_acompress: dma_map_sg, src_addr 223925c000, nr_sgs 1, req->src 00000000ee7cb5e6, req->slen 4096, sg_dma_len(sg) 4096
|
||||
[ 404.202973] idxd 0000:e7:02.0: iaa_comp_acompress: dma_map_sg, dst_addr 21dadf8000, nr_sgs 1, req->dst 000000008d6acea8, req->dlen 4096, sg_dma_len(sg) 8192
|
||||
[ 404.202975] idxd 0000:e7:02.0: iaa_compress: desc->src1_addr 223925c000, desc->src1_size 4096, desc->dst_addr 21dadf8000, desc->max_dst_size 4096, desc->src2_addr 2203543000, desc->src2_size 1568
|
||||
[ 404.202981] idxd 0000:e7:02.0: iaa_compress_verify: (verify) desc->src1_addr 21dadf8000, desc->src1_size 228, desc->dst_addr 223925c000, desc->max_dst_size 4096, desc->src2_addr 0, desc->src2_size 0
|
||||
...
|
||||
|
||||
Now that basic functionality has been demonstrated, the defaults can
|
||||
be erased and replaced with a different configuration. To do that,
|
||||
first disable zswap::
|
||||
|
||||
# echo lzo > /sys/module/zswap/parameters/compressor
|
||||
# swapoff -a
|
||||
# echo 0 > /sys/module/zswap/parameters/accept_threshold_percent
|
||||
# echo 0 > /sys/module/zswap/parameters/max_pool_percent
|
||||
# echo 0 > /sys/module/zswap/parameters/enabled
|
||||
# echo 0 > /sys/module/zswap/parameters/enabled
|
||||
|
||||
Then run the :ref:`iaa_disable_script` in the 'Use Cases' section
|
||||
below to disable the default configuration.
|
||||
|
||||
Finally turn swap back on::
|
||||
|
||||
# swapon -a
|
||||
|
||||
Following all that the IAA device(s) can now be re-configured and
|
||||
enabled as desired for further testing. Below is one example.
|
||||
|
||||
The zswap test expects the work queues for each IAA device on the
|
||||
system to be configured properly as a kernel workqueue with a
|
||||
workqueue driver_name of "crypto".
|
||||
|
||||
The below script automatically does that::
|
||||
|
||||
#!/bin/bash
|
||||
|
||||
echo "IAA devices:"
|
||||
lspci -d:0cfe
|
||||
echo "# IAA devices:"
|
||||
lspci -d:0cfe | wc -l
|
||||
|
||||
#
|
||||
# count iaa instances
|
||||
#
|
||||
iaa_dev_id="0cfe"
|
||||
num_iaa=$(lspci -d:${iaa_dev_id} | wc -l)
|
||||
echo "Found ${num_iaa} IAA instances"
|
||||
|
||||
#
|
||||
# disable iaa wqs and devices
|
||||
#
|
||||
echo "Disable IAA"
|
||||
|
||||
for ((i = 1; i < ${num_iaa} * 2; i += 2)); do
|
||||
echo disable wq iax${i}/wq${i}.0
|
||||
accel-config disable-wq iax${i}/wq${i}.0
|
||||
echo disable iaa iax${i}
|
||||
accel-config disable-device iax${i}
|
||||
done
|
||||
|
||||
echo "End Disable IAA"
|
||||
|
||||
#
|
||||
# configure iaa wqs and devices
|
||||
#
|
||||
echo "Configure IAA"
|
||||
for ((i = 1; i < ${num_iaa} * 2; i += 2)); do
|
||||
accel-config config-wq --group-id=0 --mode=dedicated --size=128 --priority=10 --type=kernel --name="iaa_crypto" --driver_name="crypto" iax${i}/wq${i}
|
||||
done
|
||||
|
||||
echo "End Configure IAA"
|
||||
|
||||
#
|
||||
# enable iaa wqs and devices
|
||||
#
|
||||
echo "Enable IAA"
|
||||
|
||||
for ((i = 1; i < ${num_iaa} * 2; i += 2)); do
|
||||
echo enable iaa iaa${i}
|
||||
accel-config enable-device iaa${i}
|
||||
echo enable wq iaa${i}/wq${i}.0
|
||||
accel-config enable-wq iaa${i}/wq${i}.0
|
||||
done
|
||||
|
||||
echo "End Enable IAA"
|
||||
|
||||
When the workqueues are bound to the iaa_crypto driver, you should
|
||||
see something similar to the following in dmesg output if you've
|
||||
enabled debug output (echo -n 'module iaa_crypto +p' >
|
||||
/sys/kernel/debug/dynamic_debug/control)::
|
||||
|
||||
[ 60.752344] idxd 0000:f6:02.0: add_iaa_wq: added wq 000000004068d14d to iaa 00000000c9585ba2, n_wq 1
|
||||
[ 60.752346] iaa_crypto: rebalance_wq_table: nr_nodes=2, nr_cpus 160, nr_iaa 8, cpus_per_iaa 20
|
||||
[ 60.752347] iaa_crypto: rebalance_wq_table: iaa=0
|
||||
[ 60.752349] idxd 0000:6a:02.0: request_iaa_wq: getting wq from iaa_device 0000000042d7bc52 (0)
|
||||
[ 60.752350] idxd 0000:6a:02.0: request_iaa_wq: returning unused wq 00000000c8bb4452 (0) from iaa device 0000000042d7bc52 (0)
|
||||
[ 60.752352] iaa_crypto: rebalance_wq_table: assigned wq for cpu=0, node=0 = wq 00000000c8bb4452
|
||||
[ 60.752354] iaa_crypto: rebalance_wq_table: iaa=0
|
||||
[ 60.752355] idxd 0000:6a:02.0: request_iaa_wq: getting wq from iaa_device 0000000042d7bc52 (0)
|
||||
[ 60.752356] idxd 0000:6a:02.0: request_iaa_wq: returning unused wq 00000000c8bb4452 (0) from iaa device 0000000042d7bc52 (0)
|
||||
[ 60.752358] iaa_crypto: rebalance_wq_table: assigned wq for cpu=1, node=0 = wq 00000000c8bb4452
|
||||
[ 60.752359] iaa_crypto: rebalance_wq_table: iaa=0
|
||||
[ 60.752360] idxd 0000:6a:02.0: request_iaa_wq: getting wq from iaa_device 0000000042d7bc52 (0)
|
||||
[ 60.752361] idxd 0000:6a:02.0: request_iaa_wq: returning unused wq 00000000c8bb4452 (0) from iaa device 0000000042d7bc52 (0)
|
||||
[ 60.752362] iaa_crypto: rebalance_wq_table: assigned wq for cpu=2, node=0 = wq 00000000c8bb4452
|
||||
[ 60.752364] iaa_crypto: rebalance_wq_table: iaa=0
|
||||
.
|
||||
.
|
||||
.
|
||||
|
||||
Once the workqueues and devices have been enabled, the IAA crypto
|
||||
algorithms are enabled and available. When the IAA crypto algorithms
|
||||
have been successfully enabled, you should see the following dmesg
|
||||
output::
|
||||
|
||||
[ 64.893759] iaa_crypto: iaa_crypto_enable: iaa_crypto now ENABLED
|
||||
|
||||
Now run the following zswap-specific setup commands to have zswap use
|
||||
the 'fixed' compression mode::
|
||||
|
||||
echo 0 > /sys/module/zswap/parameters/enabled
|
||||
echo 50 > /sys/module/zswap/parameters/max_pool_percent
|
||||
echo deflate-iaa > /sys/module/zswap/parameters/compressor
|
||||
echo zsmalloc > /sys/module/zswap/parameters/zpool
|
||||
echo 1 > /sys/module/zswap/parameters/enabled
|
||||
echo 0 > /sys/module/zswap/parameters/same_filled_pages_enabled
|
||||
|
||||
echo 100 > /proc/sys/vm/swappiness
|
||||
echo never > /sys/kernel/mm/transparent_hugepage/enabled
|
||||
echo 1 > /proc/sys/vm/overcommit_memory
|
||||
|
||||
Finally, you can now run the zswap workload you want to measure. For
|
||||
example, using the code below, the following command will swap in and
|
||||
out 100 pages::
|
||||
|
||||
./memory_madvise 100
|
||||
|
||||
Allocating 100 pages to swap in/out
|
||||
Swapping out 100 pages
|
||||
Swapping in 100 pages
|
||||
Swapped out and in 100 pages
|
||||
|
||||
You should see something like the following in the dmesg output if
|
||||
you've enabled debug output (echo -n 'module iaa_crypto +p' >
|
||||
/sys/kernel/debug/dynamic_debug/control)::
|
||||
|
||||
[ 404.202972] idxd 0000:e7:02.0: iaa_comp_acompress: dma_map_sg, src_addr 223925c000, nr_sgs 1, req->src 00000000ee7cb5e6, req->slen 4096, sg_dma_len(sg) 4096
|
||||
[ 404.202973] idxd 0000:e7:02.0: iaa_comp_acompress: dma_map_sg, dst_addr 21dadf8000, nr_sgs 1, req->dst 000000008d6acea8, req->dlen 4096, sg_dma_len(sg) 8192
|
||||
[ 404.202975] idxd 0000:e7:02.0: iaa_compress: desc->src1_addr 223925c000, desc->src1_size 4096, desc->dst_addr 21dadf8000, desc->max_dst_size 4096, desc->src2_addr 2203543000, desc->src2_size 1568
|
||||
[ 404.202981] idxd 0000:e7:02.0: iaa_compress_verify: (verify) desc->src1_addr 21dadf8000, desc->src1_size 228, desc->dst_addr 223925c000, desc->max_dst_size 4096, desc->src2_addr 0, desc->src2_size 0
|
||||
[ 409.203227] idxd 0000:e7:02.0: iaa_comp_adecompress: dma_map_sg, src_addr 21ddd8b100, nr_sgs 1, req->src 0000000084adab64, req->slen 228, sg_dma_len(sg) 228
|
||||
[ 409.203235] idxd 0000:e7:02.0: iaa_comp_adecompress: dma_map_sg, dst_addr 21ee3dc000, nr_sgs 1, req->dst 000000004e2990d0, req->dlen 4096, sg_dma_len(sg) 4096
|
||||
[ 409.203239] idxd 0000:e7:02.0: iaa_decompress: desc->src1_addr 21ddd8b100, desc->src1_size 228, desc->dst_addr 21ee3dc000, desc->max_dst_size 4096, desc->src2_addr 0, desc->src2_size 0
|
||||
[ 409.203254] idxd 0000:e7:02.0: iaa_comp_adecompress: dma_map_sg, src_addr 21ddd8b100, nr_sgs 1, req->src 0000000084adab64, req->slen 228, sg_dma_len(sg) 228
|
||||
[ 409.203256] idxd 0000:e7:02.0: iaa_comp_adecompress: dma_map_sg, dst_addr 21f1551000, nr_sgs 1, req->dst 000000004e2990d0, req->dlen 4096, sg_dma_len(sg) 4096
|
||||
[ 409.203257] idxd 0000:e7:02.0: iaa_decompress: desc->src1_addr 21ddd8b100, desc->src1_size 228, desc->dst_addr 21f1551000, desc->max_dst_size 4096, desc->src2_addr 0, desc->src2_size 0
|
||||
|
||||
In order to unregister the IAA crypto algorithms, and register new
|
||||
ones using different parameters, any users of the current algorithm
|
||||
should be stopped and the IAA workqueues and devices disabled.
|
||||
|
||||
In the case of zswap, remove the IAA crypto algorithm as the
|
||||
compressor and turn off swap (to remove all references to
|
||||
iaa_crypto)::
|
||||
|
||||
echo lzo > /sys/module/zswap/parameters/compressor
|
||||
swapoff -a
|
||||
|
||||
echo 0 > /sys/module/zswap/parameters/accept_threshold_percent
|
||||
echo 0 > /sys/module/zswap/parameters/max_pool_percent
|
||||
echo 0 > /sys/module/zswap/parameters/enabled
|
||||
|
||||
Once zswap is disabled and no longer using iaa_crypto, the IAA wqs and
|
||||
devices can be disabled.
|
||||
|
||||
.. _iaa_disable_script:
|
||||
|
||||
IAA disable script
|
||||
------------------
|
||||
|
||||
The below script automatically does that::
|
||||
|
||||
#!/bin/bash
|
||||
|
||||
echo "IAA devices:"
|
||||
lspci -d:0cfe
|
||||
echo "# IAA devices:"
|
||||
lspci -d:0cfe | wc -l
|
||||
|
||||
#
|
||||
# count iaa instances
|
||||
#
|
||||
iaa_dev_id="0cfe"
|
||||
num_iaa=$(lspci -d:${iaa_dev_id} | wc -l)
|
||||
echo "Found ${num_iaa} IAA instances"
|
||||
|
||||
#
|
||||
# disable iaa wqs and devices
|
||||
#
|
||||
echo "Disable IAA"
|
||||
|
||||
for ((i = 1; i < ${num_iaa} * 2; i += 2)); do
|
||||
echo disable wq iax${i}/wq${i}.0
|
||||
accel-config disable-wq iax${i}/wq${i}.0
|
||||
echo disable iaa iax${i}
|
||||
accel-config disable-device iax${i}
|
||||
done
|
||||
|
||||
echo "End Disable IAA"
|
||||
|
||||
Finally, at this point the iaa_crypto module can be removed, which
|
||||
will unregister the current IAA crypto algorithms::
|
||||
|
||||
rmmod iaa_crypto
|
||||
|
||||
|
||||
memory_madvise.c (gcc -o memory_memadvise memory_madvise.c)::
|
||||
|
||||
#include <stdio.h>
|
||||
#include <stdlib.h>
|
||||
#include <string.h>
|
||||
#include <unistd.h>
|
||||
#include <sys/mman.h>
|
||||
#include <linux/mman.h>
|
||||
|
||||
#ifndef MADV_PAGEOUT
|
||||
#define MADV_PAGEOUT 21 /* force pages out immediately */
|
||||
#endif
|
||||
|
||||
#define PG_SZ 4096
|
||||
|
||||
int main(int argc, char **argv)
|
||||
{
|
||||
int i, nr_pages = 1;
|
||||
int64_t *dump_ptr;
|
||||
char *addr, *a;
|
||||
int loop = 1;
|
||||
|
||||
if (argc > 1)
|
||||
nr_pages = atoi(argv[1]);
|
||||
|
||||
printf("Allocating %d pages to swap in/out\n", nr_pages);
|
||||
|
||||
/* allocate pages */
|
||||
addr = mmap(NULL, nr_pages * PG_SZ, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
|
||||
*addr = 1;
|
||||
|
||||
/* initialize data in page to all '*' chars */
|
||||
memset(addr, '*', nr_pages * PG_SZ);
|
||||
|
||||
printf("Swapping out %d pages\n", nr_pages);
|
||||
|
||||
/* Tell kernel to swap it out */
|
||||
madvise(addr, nr_pages * PG_SZ, MADV_PAGEOUT);
|
||||
|
||||
while (loop > 0) {
|
||||
/* Wait for swap out to finish */
|
||||
sleep(5);
|
||||
|
||||
a = addr;
|
||||
|
||||
printf("Swapping in %d pages\n", nr_pages);
|
||||
|
||||
/* Access the page ... this will swap it back in again */
|
||||
for (i = 0; i < nr_pages; i++) {
|
||||
if (a[0] != '*') {
|
||||
printf("Bad data from decompress!!!!!\n");
|
||||
|
||||
dump_ptr = (int64_t *)a;
|
||||
for (int j = 0; j < 100; j++) {
|
||||
printf(" page %d data: %#llx\n", i, *dump_ptr);
|
||||
dump_ptr++;
|
||||
}
|
||||
}
|
||||
|
||||
a += PG_SZ;
|
||||
}
|
||||
|
||||
loop --;
|
||||
}
|
||||
|
||||
printf("Swapped out and in %d pages\n", nr_pages);
|
||||
|
||||
Appendix
|
||||
========
|
||||
|
||||
.. _iaa_sysfs_config:
|
||||
|
||||
IAA sysfs config interface
|
||||
--------------------------
|
||||
|
||||
Below is a description of the IAA sysfs interface, which as mentioned
|
||||
in the main document, should only be used if you know exactly what you
|
||||
are doing. Even then, there's no compelling reason to use it directly
|
||||
since accel-config can do everything the sysfs interface can and in
|
||||
fact accel-config is based on it under the covers.
|
||||
|
||||
The 'IAA config path' is /sys/bus/dsa/devices and contains
|
||||
subdirectories representing each IAA device, workqueue, engine, and
|
||||
group. Note that in the sysfs interface, the IAA devices are actually
|
||||
named using iax e.g. iax1, iax3, etc. (Note that IAA devices are the
|
||||
odd-numbered devices; the even-numbered devices are DSA devices and
|
||||
can be ignored for IAA).
|
||||
|
||||
The 'IAA device bind path' is /sys/bus/dsa/drivers/idxd/bind and is
|
||||
the file that is written to enable an IAA device.
|
||||
|
||||
The 'IAA workqueue bind path' is /sys/bus/dsa/drivers/crypto/bind and
|
||||
is the file that is written to enable an IAA workqueue.
|
||||
|
||||
Similarly /sys/bus/dsa/drivers/idxd/unbind and
|
||||
/sys/bus/dsa/drivers/crypto/unbind are used to disable IAA devices and
|
||||
workqueues.
|
||||
|
||||
The basic sequence of commands needed to set up the IAA devices and
|
||||
workqueues is:
|
||||
|
||||
For each device::
|
||||
1) Disable any workqueues enabled on the device. For example to
|
||||
disable workques 0 and 1 on IAA device 3::
|
||||
|
||||
# echo wq3.0 > /sys/bus/dsa/drivers/crypto/unbind
|
||||
# echo wq3.1 > /sys/bus/dsa/drivers/crypto/unbind
|
||||
|
||||
2) Disable the device. For example to disable IAA device 3::
|
||||
|
||||
# echo iax3 > /sys/bus/dsa/drivers/idxd/unbind
|
||||
|
||||
3) configure the desired workqueues. For example, to configure
|
||||
workqueue 3 on IAA device 3::
|
||||
|
||||
# echo dedicated > /sys/bus/dsa/devices/iax3/wq3.3/mode
|
||||
# echo 128 > /sys/bus/dsa/devices/iax3/wq3.3/size
|
||||
# echo 0 > /sys/bus/dsa/devices/iax3/wq3.3/group_id
|
||||
# echo 10 > /sys/bus/dsa/devices/iax3/wq3.3/priority
|
||||
# echo "kernel" > /sys/bus/dsa/devices/iax3/wq3.3/type
|
||||
# echo "iaa_crypto" > /sys/bus/dsa/devices/iax3/wq3.3/name
|
||||
# echo "crypto" > /sys/bus/dsa/devices/iax3/wq3.3/driver_name
|
||||
|
||||
4) Enable the device. For example to enable IAA device 3::
|
||||
|
||||
# echo iax3 > /sys/bus/dsa/drivers/idxd/bind
|
||||
|
||||
5) Enable the desired workqueues on the device. For example to
|
||||
enable workques 0 and 1 on IAA device 3::
|
||||
|
||||
# echo wq3.0 > /sys/bus/dsa/drivers/crypto/bind
|
||||
# echo wq3.1 > /sys/bus/dsa/drivers/crypto/bind
|
||||
20
Documentation/driver-api/crypto/iaa/index.rst
Normal file
20
Documentation/driver-api/crypto/iaa/index.rst
Normal file
@ -0,0 +1,20 @@
|
||||
.. SPDX-License-Identifier: GPL-2.0
|
||||
|
||||
=================================
|
||||
IAA (Intel Analytics Accelerator)
|
||||
=================================
|
||||
|
||||
IAA provides hardware compression and decompression via the crypto
|
||||
API.
|
||||
|
||||
.. toctree::
|
||||
:maxdepth: 1
|
||||
|
||||
iaa-crypto
|
||||
|
||||
.. only:: subproject and html
|
||||
|
||||
Indices
|
||||
=======
|
||||
|
||||
* :ref:`genindex`
|
||||
20
Documentation/driver-api/crypto/index.rst
Normal file
20
Documentation/driver-api/crypto/index.rst
Normal file
@ -0,0 +1,20 @@
|
||||
.. SPDX-License-Identifier: GPL-2.0
|
||||
|
||||
==============
|
||||
Crypto Drivers
|
||||
==============
|
||||
|
||||
Documentation for crypto drivers that may need more involved setup and
|
||||
configuration.
|
||||
|
||||
.. toctree::
|
||||
:maxdepth: 1
|
||||
|
||||
iaa/index
|
||||
|
||||
.. only:: subproject and html
|
||||
|
||||
Indices
|
||||
=======
|
||||
|
||||
* :ref:`genindex`
|
||||
@ -115,6 +115,7 @@ available subsections can be seen below.
|
||||
hte/index
|
||||
wmi
|
||||
dpll
|
||||
crypto/index
|
||||
|
||||
.. only:: subproject and html
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user