On Mon, Jan 18, 2021 at 10:21:03AM -0800, Alexander Duyck wrote: > On Mon, Jan 18, 2021 at 5:28 AM Leon Romanovsky <leon@xxxxxxxxxx> wrote: > > > > On Mon, Jan 18, 2021 at 09:20:08AM +0200, Leon Romanovsky wrote: > > > On Sun, Jan 17, 2021 at 07:16:30PM -0800, Alexander Duyck wrote: > > > > On Sat, Jan 16, 2021 at 12:20 AM Leon Romanovsky <leon@xxxxxxxxxx> wrote: > > > > > > > > > > On Fri, Jan 15, 2021 at 05:48:59PM -0800, Alexander Duyck wrote: > > > > > > On Fri, Jan 15, 2021 at 7:53 AM Leon Romanovsky <leon@xxxxxxxxxx> wrote: > > > > > > > > > > > > > > On Fri, Jan 15, 2021 at 10:06:19AM -0400, Jason Gunthorpe wrote: > > > > > > > > On Thu, Jan 14, 2021 at 05:56:20PM -0800, Alexander Duyck wrote: > > > > <...> > > > > > > If you want yet another compromise I would be much happier with the PF > > > > registering the sysfs interfaces on the VFs rather than the VFs > > > > registering the interface and hoping the PF supports it. At least with > > > > that you are guaranteed the PF will respond to the interface when it > > > > is registered. > > > > > > Thanks a lot, I appreciate it, will take a look now. > > > > I found only two solutions to implement it in this way. > > Option 1. > > Allow multi entry write to some new sysfs knob that will receive BDF (or another VF > > identification) and vector count. Something like this: > > > > echo "0000:01:00.2 123" > sriov_vf_msix_count > > > > From one side, that solution is unlikely to be welcomed by Greg KH and from another, > > it will require a lot of boilerplate code to make it safe and correct. > > You are overthinking this. I didn't say the sysfs had to be in the PF > directory itself. My request was that the PF is what placed the sysfs > file in the directory since indirectly it is responsible for spawning > the VF anyway it shouldn't be too much of a lift to have the PF place > sysfs files in the VF hierarchy. > > The main piece I am not a fan of is the fact that the VF is blindly > registering an interface and presenting it without knowing if it even > works. > > The secondary issue that I see as important, but I am willing to > compromise on is that the interface makes it appear as though the VF > configuration space is writable via this sysfs file. My preference > would be to somehow make it transparent that the PF is providing this > functionality. I thought it might be easier to do with devlink rather > than with sysfs which is why I have been preferring devlink. However > based on your pushback I am willing to give up on that, but I think we > still need to restructure how the sysfs is being managed. > > > Option 2. > > Create directory under PF device with files writable and organized by VF numbers. > > It is doable, but will cause to code bloat with no gain at all. Cleaner than now, > > it won't be. > > > > Why the current approach with one file per-proper VF device is not good enough? > > Because it is muddying the waters in terms of what is control taking > place from the VF versus the PF. In my mind the ideal solution if you > insist on going with the VF sysfs route would be to look at spawning a > directory inside the VF sysfs specifically for all of the instances > that will be PF management controls. At least that would give some > hint that this is a backdoor control and not actually interacting with > the VF PCI device directly. Then if in the future you have to add more > to this you have a spot already laid out and the controls won't be > mistaken for standard PCI controls as they are PF management controls. > > In addition you could probably even create a directory on the PF with > the new control you had added for getting the master count as well as > look at adding symlinks to the VF files so that you could manage all > of the resources in one spot. That would result in the controls being > nicely organized and easy to use. Thanks, for you inputs. I'll try offline different variants and will post v4 soon.
