[dpdk-dev,v8,14/14] doc: Add port hotplug framework section to programmers guide
Commit Message
This patch adds a new section for describing port hotplug framework.
Signed-off-by: Tetsuya Mukawa <mukawa@igel.co.jp>
---
doc/guides/prog_guide/index.rst | 1 +
doc/guides/prog_guide/port_hotplug_framework.rst | 110 +++++++++++++++++++++++
2 files changed, 111 insertions(+)
create mode 100644 doc/guides/prog_guide/port_hotplug_framework.rst
Comments
> -----Original Message-----
> From: Tetsuya Mukawa [mailto:mukawa@igel.co.jp]
> Sent: Monday, February 16, 2015 4:15 AM
> To: dev@dpdk.org
> Cc: Qiu, Michael; Iremonger, Bernard; Tetsuya Mukawa
> Subject: [PATCH v8 14/14] doc: Add port hotplug framework section to programmers guide
>
> This patch adds a new section for describing port hotplug framework.
>
> Signed-off-by: Tetsuya Mukawa <mukawa@igel.co.jp>
Acked-by: Bernard Iremonger <bernard.iremonger@intel.com>
@@ -70,6 +70,7 @@ Programmer's Guide
packet_classif_access_ctrl
packet_framework
vhost_lib
+ port_hotplug_framework
source_org
dev_kit_build_system
dev_kit_root_make_help
new file mode 100644
@@ -0,0 +1,110 @@
+.. BSD LICENSE
+ Copyright(c) 2015 IGEL Co.,Ltd. All rights reserved.
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions
+ are met:
+
+ * Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in
+ the documentation and/or other materials provided with the
+ distribution.
+ * Neither the name of IGEL Co.,Ltd. nor the names of its
+ contributors may be used to endorse or promote products derived
+ from this software without specific prior written permission.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+Port Hotplug Framework
+======================
+
+The Port Hotplug Framework provides DPDK applications with the ability to
+attach and detach ports at runtime. Because the framework depends on PMD
+implementation, the ports that PMDs cannot handle are out of scope of this
+framework. Furthermore, after detaching a port from a DPDK application, the
+framework doesn't provide a way for removing the devices from the system.
+For the ports backed by a physical NIC, the kernel will need to support PCI
+Hotplug feature.
+
+Overview
+--------
+
+The basic requirements of the Port Hotplug Framework are:
+
+* DPDK applications that use the Port Hotplug Framework must manage their
+ own ports.
+
+ The Port Hotplug Framework is implemented to allow DPDK applications to
+ manage ports. For example, when DPDK applications call the port attach
+ function, the attached port number is returned. DPDK applications can
+ also detach the port by port number.
+
+* Kernel support is needed for attaching or detaching physical device
+ ports.
+
+ To attach new physical device ports, the device will be recognized by
+ userspace driver I/O framework in kernel at first. Then DPDK
+ applications can call the Port Hotplug functions to attach the ports.
+ For detaching, steps are vice versa.
+
+* Before detaching, they must be stopped and closed.
+
+ DPDK applications must call "rte_eth_dev_stop()" and
+ "rte_eth_dev_close()" APIs before detaching ports. These functions will
+ start finalization sequence of the PMDs.
+
+* The framework doesn't affect legacy DPDK applications behavior.
+
+ If the Port Hotplug functions aren't called, all legacy DPDK apps can
+ still work without modifications.
+
+Port Hotplug API overview
+-------------------------
+
+* Attaching a port
+
+ "rte_eal_dev_attach()" API attaches a port to DPDK application, and
+ returns the attached port number. Before calling the API, the device
+ should be recognized by an userspace driver I/O framework. The API
+ receives a pci address like "0000:01:00.0" or a virtual device name
+ like "eth_pcap0,iface=eth0". In the case of virtual device name, the
+ format is the same as the general "--vdev" option of DPDK.
+
+* Detaching a port
+
+ "rte_eal_dev_detach()" API detaches a port from DPDK application, and
+ returns a pci address of the detached device or a virtual device name
+ of the device.
+
+Reference
+---------
+
+ "testpmd" supports the Port Hotplug Framework.
+
+Limitations
+-----------
+
+* The Port Hotplug APIs are not thread safe.
+
+* The framework can only be enabled with Linux. BSD is not supported.
+
+* To detach a port, the port should be backed by a device that igb_uio
+ manages. VFIO is not supported.
+
+* Not all PMDs support detaching feature.
+ To know whether a PMD can support detaching, search for the
+ "RTE_PCI_DRV_DETACHABLE" flag in PMD implementation. If the flag is
+ defined in the PMD, detaching is supported.