numam-dpdk/doc/guides/prog_guide/port_hotplug_framework.rst
Thomas Monjalon 5fc07e3eb7 app/test: fix vdev names
The vdev eth_ring has been renamed to net_ring.
Some unit tests are using the old name and fail.

Fixes also the vdev comments in EAL and ethdev.

Fixes: 2f45703c17 ("drivers: make driver names consistent")

Signed-off-by: Thomas Monjalon <thomas.monjalon@6wind.com>
Acked-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
2016-10-13 15:55:42 +02:00

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.. BSD LICENSE
Copyright(c) 2015 IGEL Co.,Ltd. All rights reserved.
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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_eth_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 "net_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_eth_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.