On Wed, Jun 7, 2017 at 9:55 PM, Gaëtan Rivet <gaetan.ri...@6wind.com> wrote: > On Wed, Jun 07, 2017 at 07:22:05PM +0200, Jan Blunck wrote: >> On Wed, May 24, 2017 at 5:12 PM, Gaetan Rivet <gaetan.ri...@6wind.com> wrote: >> > Following the evolutions announced in [1], here is the first part of >> > the rte_devargs rework planned for 17.08. The rationale has been partially >> > explained in [2]. >> > >> > This first part covers the introduction of the necessary facilities in >> > rte_bus to allow for generic device parsing. This API is implemented for >> > the virtual and PCI buses. Additionally, this rte_bus evolution is being >> > used within rte_devargs to characterize a device type by its bus. >> > This work is the first of two parts to reduce the dependency of the EAL >> > upon specific bus implementations. >> > >> > Two public functions are added to rte_bus to help bus recognition: >> > >> > - rte_bus_from_name >> > - rte_bus_from_dev >> > >> > These functions are made public because the bus handle within devargs >> > becomes the generic device type. Recognizing device types is useful for >> > buses and PMDs alike. >> > The modified rte_devargs parsing allows declaring on the EAL command line >> > explicit buses to handle a device. The format is as follow: >> > >> > --vdev="virtual:net_ring0" --vdev="net_tap0,iface=tap0" >> > -w PCI:00:02.0 -w 00:03.0 >> > >> >> I don't see the point of doing this. The --vdev parameter implicitly >> defines the bus by its name (--vdev aka virtual device). >> >> Why don't you add a commandline "--dev" parameter that supports a >> "bus=" devarg? You would need to clarify what that means for other >> busses than the virtual one. Is the bus switched into whitelist mode >> by that? >> >> > > We cannot keep the current -w, -b and --vdev parameter. Those are > processed by the EAL, and use specifics from the virtual and PCI buses. > > The rte_devargs rework has been to make the same functionality generic > to all rte_bus. As seen quickly in [2], rte_devargs has two functions: > > * Validating a device declaration > * Keeping the relevant device info until it has been processed. >
I don't agree with the validation step. This is highly device/driver/bus specific and I don't believe that just because you have created a rte_devargs it is a guarantee that the device is valid. Besides that it makes statically embedding rte_devargs into other structures impossible. As I see it rte_devargs is a key-value list with some keys that are generic. This would make application development much easier. > Both functionalities have been genericized. This results in all parameters > being able to be used with all types of devices. This is inherent to the > EAL becoming bus-agnostic. > > Now, it is absolutely possible to rename for example -w as --dev, as it > is the expected behavior from users. This however should be discussed by > the community, last time I talked about the possibility of switching the > default of the PCI bus to whitelist mode the community wasn't all that > enthused by the prospect. > > Finally, I do not like the idea of a special devarg just for declaring > explicitly buses for devices. The bus is not a device modifier, nor is > it a driver parameter. The bus is a way to define the location of the > device on the system. Adding a special "bus=" devargs means having some > preprocessing done on devargs upon rte_devargs allocation. This was > already abused by the bonding PMD with the driver= parameter. I do not > support this and did not want to repeat it. Passing down the device args > is a simple process and we should keep it as simple as possible. > > I know you do not like having the bus as part of the device name. > As a compromise, I made the current system flexible and allowed the legacy > device definition to be kept. > > However with a purely generic process, it is necessary to at least offer > the possibility to the user to explicitly use a bus, as nothing prevents > conflicting device names from existing. > >> > [2]: http://dpdk.org/ml/archives/dev/2017-May/065670.html > >> > This explicit bus designation is optional; no evolution is currently >> > forced on users to migrate to this new format. The separating character is >> > arbitrary and can be any character illegal within a bus name. >> > Subsequently, what is allowed within a bus name has been formally >> > defined and is now enforced. >> > >> > [1]: http://dpdk.org/ml/archives/dev/2017-May/065634.html >> > [2]: http://dpdk.org/ml/archives/dev/2017-May/065670.html >> > >> > This patchset depends on: >> > >> > bus: attach / detach API >> > http://dpdk.org/ml/archives/dev/2017-May/066330.html >> > http://dpdk.org/dev/patchwork/patch/24489/ >> > >> > Gaetan Rivet (9): >> > bus: fix bus name registration >> > bus: verify bus name on registration >> > bus: introduce parsing functionality >> > vdev: implement parse bus operation >> > pci: implement parse bus operation >> > bus: add helper to find bus from a name >> > bus: add helper to find a bus from a device name >> > vdev: expose bus name >> > devargs: parse bus info >> > >> > lib/librte_eal/bsdapp/eal/rte_eal_version.map | 8 +++ >> > lib/librte_eal/common/eal_common_bus.c | 47 +++++++++++++++++ >> > lib/librte_eal/common/eal_common_devargs.c | 17 +++++- >> > lib/librte_eal/common/eal_common_pci.c | 19 +++++++ >> > lib/librte_eal/common/eal_common_vdev.c | 70 >> > ++++++++++++++----------- >> > lib/librte_eal/common/eal_private.h | 16 ++++++ >> > lib/librte_eal/common/include/rte_bus.h | 49 ++++++++++++++++- >> > lib/librte_eal/common/include/rte_devargs.h | 3 ++ >> > lib/librte_eal/common/include/rte_vdev.h | 2 + >> > lib/librte_eal/linuxapp/eal/rte_eal_version.map | 8 +++ >> > 10 files changed, 205 insertions(+), 34 deletions(-) >> > >> > -- >> > 2.1.4 >> > > > -- > Gaėtan Rivet > 6WIND
