[PATCH] docs/migration: add qatzip compression feature

[Yuan Liu]

add Intel QATzip compression method introduction

Signed-off-by: Yuan Liu <yuan1.liu@intel.com>
Reviewed-by: Nanhai Zou <nanhai.zou@intel.com>
---
 docs/devel/migration/features.rst           |   1 +
 docs/devel/migration/qatzip-compression.rst | 112 ++++++++++++++++++++
 2 files changed, 113 insertions(+)
 create mode 100644 docs/devel/migration/qatzip-compression.rst

diff --git a/docs/devel/migration/features.rst 
b/docs/devel/migration/features.rst
index 58f8fd9e16..8f431d52f9 100644
--- a/docs/devel/migration/features.rst
+++ b/docs/devel/migration/features.rst
@@ -14,3 +14,4 @@ Migration has plenty of features to support different use 
cases.
    CPR
    qpl-compression
    uadk-compression
+   qatzip-compression
diff --git a/docs/devel/migration/qatzip-compression.rst 
b/docs/devel/migration/qatzip-compression.rst
new file mode 100644
index 0000000000..8e2137652c
--- /dev/null
+++ b/docs/devel/migration/qatzip-compression.rst
@@ -0,0 +1,112 @@
+==================
+QATzip Compression
+==================
+In scenarios with limited network bandwidth, the ``QATzip`` solution can help
+users save a lot of host CPU resources by accelerating compression and
+decompression through the Intel QuickAssist Technology(``QAT``) hardware.
+
+``QATzip`` is a user space library which builds on top of the Intel QuickAssist
+Technology user space library, to provide extended accelerated compression and
+decompression services.
+
+For more ``QATzip`` introduction, please refer to `QATzip Introduction
+<https://github.com/intel/QATzip?tab=readme-ov-file#introductionl>`_
+
+QATzip Compression Framework
+============================
+
+::
+
+  +----------------+
+  | MultiFd Thread |
+  +-------+--------+
+          |
+          | compress/decompress
+  +-------+--------+
+  | QATzip library |
+  +-------+--------+
+          |
+  +-------+--------+
+  |  QAT library   |
+  +-------+--------+
+          |         user space
+  --------+---------------------
+          |         kernel space
+   +------+-------+
+   |  QAT  Driver |
+   +------+-------+
+          |
+   +------+-------+
+   | QAT Devices  |
+   +--------------+
+
+
+QATzip Installation
+-------------------
+
+The ``QATzip`` installation package has been integrated into some Linux
+distributions and can be installed directly. For example, the Ubuntu Server
+24.04 LTS system can be installed using below command
+
+.. code-block:: shell
+   
+   #apt search qatzip
+   libqatzip-dev/noble 1.2.0-0ubuntu3 amd64
+     Intel QuickAssist user space library development files
+
+   libqatzip3/noble 1.2.0-0ubuntu3 amd64
+     Intel QuickAssist user space library
+
+   qatzip/noble,now 1.2.0-0ubuntu3 amd64 [installed]
+     Compression user-space tool for Intel QuickAssist Technology
+
+   #sudo apt install libqatzip-dev libqatzip3 qatzip
+
+If your system does not support the ``QATzip`` installation package, you can
+use the source code to build and install, please refer to `QATzip source code 
installation
+<https://github.com/intel/QATzip?tab=readme-ov-file#build-intel-quickassist-technology-driver>`_
+
+QAT Hardware Deployment
+-----------------------
+
+``QAT`` supports physical functions(PFs) and virtual functions(VFs) for
+deployment, and users can configure ``QAT`` resources for migration according
+to actual needs. For more details about ``QAT`` deployment, please refer to
+`Intel QuickAssist Technology Documentation
+<https://intel.github.io/quickassist/index.html>`_
+
+For more ``QAT`` hardware introduction, please refer to 
`intel-quick-assist-technology-overview
+<https://www.intel.com/content/www/us/en/architecture-and-technology/intel-quick-assist-technology-overview.html>`_
+
+How To Use QATzip Compression
+=============================
+
+1 - Install ``QATzip`` library
+
+2 - Build ``QEMU`` with ``--enable-qatzip`` parameter
+
+  E.g. configure --target-list=x86_64-softmmu --enable-kvm ``--enable-qatzip``
+
+3 - Set ``migrate_set_parameter multifd-compression qatzip``
+
+4 - Set ``migrate_set_parameter multifd-qatzip-level comp_level``, the default
+comp_level value is 1, and it supports levels from 1 to 9
+
+How To Choose Between QATzip and QPL
+====================================
+Starting from Intel 4th Gen Intel Xeon Scalable processors, codenamed Sapphire
+Rapids processor(``SPR``), it supports multiple build-in accelerators including
+``QAT`` and ``IAA``, the former can accelerate ``QATzip``, and the latter is
+used to accelerate ``QPL``.
+
+Here are some suggestions:
+
+1 - If your live migration scenario is limited network bandwidth and ``QAT``
+hardware resources exceed ``IAA``, then use the ``QATzip`` method, which
+can save a lot of host CPU resources for compression.
+
+2 - If your system cannot support shared virtual memory(SVM) technology, please
+use ``QATzip`` method because ``QPL`` performance is not good without SVM
+support.
+
+3 - For other scenarios, please use the ``QPL`` method first.
-- 
2.43.0