Hi Stephen, On Wed, May 31, 2017 at 08:34:26AM -0700, Stephen Hemminger wrote: > On Wed, 31 May 2017 15:17:45 +0200 > Gaetan Rivet <gaetan.ri...@6wind.com> wrote: > > > Following the work from Jan: > > > > This patchset introduces the attach / detach API to rte_bus. > > The rte_device structure is used as the generic device representation. > > > > This API is implemented for the virtual bus. > > The functions rte_eal_dev_attach and rte_eal_dev_detach are updated to > > use this new interface. > > > > -- > > > > 0. API rework > > ------------- > > > > I would like to propose an evolution on the API developed by Jan. > > > > The attach / detach rte_bus API is necessary to support the attach/detach > > rte_dev API. Those are two different levels for one similar functionality. > > > > Attach / detach does not allow true hotplugging, because the attach > > function expects the devices operated upon to already exist within the > > buses / sub-layers. This means that this API expects devices meta-datas > > (bus-internal device representation and associated device information > > read from the system) to be present upon attach. This part of the work > > is done during scanning. > > > > While it is best to avoid changing the public rte_dev API as it already > > exists, nothing prevents this new rte_bus API from superseeding it. > > It has been said during the previous release cycle that device hotplug > > was a feature that interested users. True hotplug is not allowed by the > > current attach / detach API. Worse, this API hinders the effort to bring > > this new functionality by squatting its semantic field. > > > > Thus, I propose to rename rte_bus attach / detach; plug / unplug. As it > > is a superset of the attach / detach functionality, it can be used to > > implement rte_dev attach / detach. Now is the right time to pivot to > > this new feature. > > > > This should help maintainers understanding the aim of this API and the > > differences with the APIs higher-up, clarify the field and allow a new > > functionality to be proposed. > > > > The vdev bus is inherently supporting the new API, however it has been > > made explicit. My implementation in the PCI bus in further patchset also > > follows the rte_bus hotplug API instead of only attach / detach. > > > > One remaining problem with the vdev bus is the rte_dev attach > > implementation, which needs the rte_devargs rework to be properly fixed. > > > > 1. Additional evolutions in the patchset > > ---------------------------------------- > > > > The RTE_VERIFY on the find_device is too stringent I think and forces > > all buses to implement a public device iterator. While it could be > > argued that it would push for quicker support for the functionality, I > > think it's possible that some buses are not interested at all in it and > > should simply be ignored. > > > > The bus devices iterator has been fixed. > > > > The internal rte_device handle was not properly setup within the > > net_ring PMD. > > > > Gaetan Rivet (2): > > vdev: implement hotplug functionality > > net/ring: fix dev handle in eth_dev > > > > Jan Blunck (9): > > bus: add bus iterator to find a particular bus > > bus: add device iterator > > bus: add helper to find bus for a particular device > > bus: add bus helper iterator to find a particular device > > bus: introduce hotplug functionality > > vdev: implement find_device bus operation > > vdev: implement unplug bus operation > > eal: make virtual driver probe and remove take rte_vdev_device > > ethdev: Use embedded rte_device to detach driver > > > > drivers/net/ring/rte_eth_ring.c | 7 ++ > > lib/librte_eal/bsdapp/eal/rte_eal_version.map | 4 + > > lib/librte_eal/common/eal_common_bus.c | 65 +++++++++++++++ > > lib/librte_eal/common/eal_common_dev.c | 100 > > ++++++++++++++++++------ > > lib/librte_eal/common/eal_common_vdev.c | 27 +++++++ > > lib/librte_eal/common/include/rte_bus.h | 87 +++++++++++++++++++++ > > lib/librte_eal/common/include/rte_dev.h | 26 ++++++ > > lib/librte_eal/linuxapp/eal/rte_eal_version.map | 3 + > > lib/librte_ether/rte_ethdev.c | 3 +- > > 9 files changed, 299 insertions(+), 23 deletions(-) > > > > LGTM > > Maybe we should evolve it by having both rte_bus and rte_dev API for one > release and mark > the rte_dev API for attach/detach as deprecated?
Sorry for the late response. I think that if the hotplug API is correctly designed, the rte_dev API could indeed be deprecated and then removed. I do not see a reason right now to keep it. -- Gaëtan Rivet 6WIND
