On Wed, Feb 17, 2021 at 03:25:22PM -0400, Jason Gunthorpe wrote:

On Wed, Feb 17, 2021 at 12:02:39PM -0600, Bjorn Helgaas wrote:

quoted

quoted

BTW, I asked more than once how these sysfs knobs should be handled
in the PCI/core.

Thanks for the pointers.  This is the first instance I can think of
where we want to create PCI core sysfs files based on a driver
binding, so there really isn't a precedent.

The MSI stuff does it today, doesn't it? eg:

virtblk_probe (this is a driver bind)
  init_vq
   virtio_find_vqs
    vp_modern_find_vqs
     vp_find_vqs
      vp_find_vqs_msix
       vp_request_msix_vectors
        pci_alloc_irq_vectors_affinity
         __pci_enable_msi_range
          msi_capability_init
	   populate_msi_sysfs
	    	ret = sysfs_create_groups(&pdev->dev.kobj, msi_irq_groups);

And the sysfs is removed during pci_disable_msi(), also called by the
driver

Yes, you're right, I didn't notice that one.

I'm not quite convinced that we clean up correctly in all cases --
pci_disable_msix(), pci_disable_msi(), pci_free_irq_vectors(),
pcim_release(), etc are called by several drivers, but in my quick
look I didn't see a guaranteed-to-be-called path to the cleanup during
driver unbind.  I probably just missed it.