[dpdk-dev] [PATCH v4 00/11] Port Hotplug Framework

Tetsuya Mukawa mukawa at igel.co.jp
Mon Jan 19 11:40:16 CET 2015


This patch series adds a dynamic port hotplug framework to DPDK.
With the patches, DPDK apps can attach or detach ports at runtime.

The basic concept of the port hotplug is like followings.
- DPDK apps must have responsibility to manage ports.
  DPDK apps only know which ports are attached or detached at the moment.
  The port hotplug framework is implemented to allow DPDK apps to manage ports.
  For example, when DPDK apps call port attach function, attached port number
  will be returned. Also DPDK apps can detach port by port number.
- Kernel support is needed for attaching or detaching physical device ports.
  To attach new device, the device will be recognized by kernel at first and
  controlled by kernel driver. Then user can bind the device to igb_uio
  by 'dpdk_nic_bind.py'. Finally, DPDK apps can call the port hotplug
  functions to attach ports.
  For detaching, steps are vice versa.
- Before detach ports, ports must be stopped and closed.
  DPDK application must call rte_eth_dev_stop() and rte_eth_dev_close() before
  detaching ports. These function will call finalization codes of PMDs.
  But so far, no PMD frees all resources allocated by initialization.
  It means PMDs are needed to be fixed to support the port hotplug.
  'RTE_PCI_DRV_DETACHABLE' is a new flag indicating a PMD supports detaching.
  Without this flag, detaching will be failed.
- Mustn't affect legacy DPDK apps.
  No DPDK EAL behavior is changed, if the port hotplug functions are't called.
  So all legacy DPDK apps can still work without modifications.

And a few limitations.
- The port hotplug functions are not thread safe.
  DPDK apps should handle it.
- Only support Linux and igb_uio so far.
  BSD and VFIO is not supported. I will send VFIO patches at least, but I don't
  have a plan to submit BSD patch so far.


Here is port hotplug APIs.
-------------------------------------------------------------------------------
/**
 * Attach a new device.
 *
 * @param devargs
 *   A pointer to a strings array describing the new device
 *   to be attached. The strings should be a pci address like
 *   '0000:01:00.0' or virtual device name like 'eth_pcap0'.
 * @param port_id
 *  A pointer to a port identifier actually attached.
 * @return
 *  0 on success and port_id is filled, negative on error
 */
int rte_eal_dev_attach(const char *devargs, uint8_t *port_id);

/**
 * Detach a device.
 *
 * @param port_id
 *   The port identifier of the device to detach.
 * @param addr
 *  A pointer to a device name actually detached.
 * @return
 *  0 on success and devname is filled, negative on error
 */
int rte_eal_dev_detach(uint8_t port_id, char *devname);
-------------------------------------------------------------------------------

This patch series are for DPDK EAL. To use port hotplug function by DPDK apps,
each PMD should be fixed to support 'RTE_PCI_DRV_DETACHABLE' flag. Please check
a patch for pcap PMD.

Also please check testpmd patch. It will show you how to fix your legacy
applications to support port hotplug feature.


PATCH v4 changes
 - Merge patches to review easier.
 - Fix indent of 'if' statement.
 - Fix calculation method of eal_compare_pci_addr().
 - Fix header file declaration.
 - Add header file to determine if hotplug can be enabled.
   (Thanks to Qiu, Michael)
 - Use braces with 'for' loop.
 - Add paramerter checking.
 - Fix sanity check code
 - Fix comments of rte_eth_dev_type.
 - Change function names.
   (Thanks to Iremonger, Bernard)

PATCH v3 changes:
 - Fix enum definition used in rte_ethdev.c.
   (Thanks to Zhang, Helin)

PATCH v2 changes:
 - Replace rte_eal_dev_attach_pdev(), rte_eal_dev_detach_pdev,
   rte_eal_dev_attach_vdev() and rte_eal_dev_detach_vdev() to
   rte_eal_dev_attach() and rte_eal_dev_detach().
 - Add parameter values checking.
 - Refashion a few functions.
   (Thanks to Iremonger, Bernard)

PATCH v1 Changes:
 - Fix error checking code of librte_eth APIs.
 - Fix issue that port from pcap PMD cannot be detached correctly.
 - Fix issue that testpmd could hang after forwarding, if attaching and detaching
   is repeatedly.
 - Fix if-condition of rte_eth_dev_get_port_by_addr().
   (Thanks to Mark Enright)

RFC PATCH v2 Changes:
- remove 'rte_eth_dev_validate_port()', and cleanup codes.


Tetsuya Mukawa (11):
  eal/pci,ethdev: Remove assumption that port will not be detached
  eal/pci: Consolidate pci address comparison APIs
  ethdev: Add rte_eth_dev_free to free specified device
  eal,ethdev: Add a function and function pointers to close ether device
  ethdev: Add functions that will be used by port hotplug functions
  eal/linux/pci: Add functions for unmapping igb_uio resources
  eal/pci: Add a function to remove the entry of devargs list
  eal/pci: Cleanup pci driver initialization code
  ethdev: Add one dev_type paramerter to rte_eth_dev_allocate
  eal/pci: Add rte_eal_dev_attach/detach() functions
  eal: Enable port hotplug framework in Linux

 app/test/virtual_pmd.c                          |   2 +-
 config/common_linuxapp                          |   5 +
 lib/librte_eal/bsdapp/eal/eal_pci.c             |  16 +-
 lib/librte_eal/common/Makefile                  |   1 +
 lib/librte_eal/common/eal_common_dev.c          | 273 +++++++++++++++
 lib/librte_eal/common/eal_common_devargs.c      |  57 ++++
 lib/librte_eal/common/eal_common_pci.c          |  92 ++++-
 lib/librte_eal/common/eal_private.h             |  36 ++
 lib/librte_eal/common/include/rte_dev.h         |  33 ++
 lib/librte_eal/common/include/rte_dev_hotplug.h |  44 +++
 lib/librte_eal/common/include/rte_devargs.h     |  18 +
 lib/librte_eal/common/include/rte_pci.h         |  76 +++++
 lib/librte_eal/linuxapp/eal/Makefile            |   1 +
 lib/librte_eal/linuxapp/eal/eal_pci.c           | 136 ++++++--
 lib/librte_eal/linuxapp/eal/eal_pci_init.h      |   8 +
 lib/librte_eal/linuxapp/eal/eal_pci_uio.c       |  67 +++-
 lib/librte_ether/rte_ethdev.c                   | 424 ++++++++++++++++++------
 lib/librte_ether/rte_ethdev.h                   | 145 +++++++-
 lib/librte_pmd_af_packet/rte_eth_af_packet.c    |   2 +-
 lib/librte_pmd_bond/rte_eth_bond_api.c          |   2 +-
 lib/librte_pmd_pcap/rte_eth_pcap.c              |   2 +-
 lib/librte_pmd_ring/rte_eth_ring.c              |   2 +-
 lib/librte_pmd_xenvirt/rte_eth_xenvirt.c        |   2 +-
 23 files changed, 1283 insertions(+), 161 deletions(-)
 create mode 100644 lib/librte_eal/common/include/rte_dev_hotplug.h

-- 
1.9.1



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