doc: update ifc NIC document

Add the SW assisted VDPA live migration feature into NIC doc.

Signed-off-by: Xiao Wang <xiao.w.wang@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

diff --git a/doc/guides/nics/ifc.rst b/doc/guides/nics/ifc.rst
index 48f9adf1d2f0fc4c63c7fa14d67ef89f77af8c83..bdf7b4e4a41afab2829442f52c943ba4c387254b 100644 (file)
--- a/doc/guides/nics/ifc.rst
+++ b/doc/guides/nics/ifc.rst
@@ -31,7 +31,8 @@ IFCVF's vendor ID and device ID are same as that of virtio net pci device,
 with its specific subsystem vendor ID and device ID. To let the device be
 probed by IFCVF driver, adding "vdpa=1" parameter helps to specify that this
 device is to be used in vDPA mode, rather than polling mode, virtio pmd will
-skip when it detects this message.
+skip when it detects this message. If no this parameter specified, device
+will not be used as a vDPA device, and it will be driven by virtio pmd.
 
 Different VF devices serve different virtio frontends which are in different
 VMs, so each VF needs to have its own DMA address translation service. During
@@ -39,6 +40,14 @@ the driver probe a new container is created for this device, with this
 container vDPA driver can program DMA remapping table with the VM's memory
 region information.
 
+The device argument "sw-live-migration=1" will configure the driver into SW
+assisted live migration mode. In this mode, the driver will set up a SW relay
+thread when LM happens, this thread will help device to log dirty pages. Thus
+this mode does not require HW to implement a dirty page logging function block,
+but will consume some percentage of CPU resource depending on the network
+throughput. If no this parameter specified, driver will rely on device's logging
+capability.
+
 Key IFCVF vDPA driver ops
 ~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -70,6 +79,7 @@ Features
 Features of the IFCVF driver are:
 
 - Compatibility with virtio 0.95 and 1.0.
+- SW assisted vDPA live migration.
 
 
 Prerequisites

diff --git a/doc/guides/rel_notes/release_19_02.rst b/doc/guides/rel_notes/release_19_02.rst
index 0b248d55d353acc2ff4d7c59a2e1f38203506462..a8c03d367eb5c3e70000df4ab1c803222fc80d9b 100644 (file)
--- a/doc/guides/rel_notes/release_19_02.rst
+++ b/doc/guides/rel_notes/release_19_02.rst
@@ -80,6 +80,13 @@ New Features
   * Added the handler to get firmware version string.
   * Added support for multicast filtering.
 
+* **Added support for SW-assisted VDPA live migration.**
+
+  This SW-assisted VDPA live migration facility helps VDPA devices without
+  logging capability to perform live migration, a mediated SW relay can help
+  devices to track dirty pages caused by DMA. IFC driver has enabled this
+  SW-assisted live migration mode.
+
 * **Added a compression performance test tool.**
 
   Added a new performance test tool to test the compressdev PMD. The tool tests