I recently felt tired enough of specifying various options for EAL, so I came up to use ini-based configuration. EAL parameters from dedicated section of ini file are parsed to argv array which is subsequently fed to rte_eal_init(). Quite handy, but maybe a little overkill.
On 01.06.2016 12:04, Yuanhan Liu wrote: > Hi all, > > I guess we (maybe just me :) have stated few times something like > "hey, this kind of stuff is good to have, but you are trying to > add an EAL CLI option for a specific subsystem/driver, which is > wrong". > > One recent example that is still fresh in my mind is the one from > Christian [0], that he made a proposal to introduce two new EAL > options, --vhost-owner and --vhost-perm, to configure the vhost > user socket file permission. > > [0]: http://dpdk.org/ml/archives/dev/2016-April/037948.html > > Another example is the one I met while enabling virtio 1.0 support. > QEMU has the ability to support both virtio 0.95 (legacy) and 1.0 > (modern) at the same time for one virtio device, therefore, we > could either use legacy driver or modern driver to operate the > device. However, the current logic is we try with modern driver > first, and then legacy driver if it failed. In above case, we will > never hit the legacy driver. But sometimes, it's nice to let it > force back to the legacy driver, say, for debug or compare purpose. > > Apparently, adding a new EAL option like "--force-legacy" looks > wrong. > > The generic yet elegant solution I just thought of while having > lunch is to add a new EAL option, say, --extra-options, where we > could specify driver/subsystem specific options. As you see, it's > nothing big deal, it just looks like Linux kernel parameters. > > Take above two cases as example, it could be: > > --extra-options "vhost-owner=kvm:kvm force-legacy" > > Note that those options could also be delimited by comma. > > DPDK EAL then will provide some generic helper functions to get > and parse those options, and let the specific driver/subsystem > to invoke them to do the actual parse and do the proper action > when some option is specified, say, virtio PMD driver will force > back to legacy driver when "force-legacy" is given. > > Comments? Makes sense to you guys, or something nice to have? > > --yliu
