Re: [PATCH v3 2/2] PCI/IOV: Fix race between SR-IOV enable/disable and hotplug

[Lukas Wunner]

On Tue, Mar 17, 2026 at 12:33:34PM +0100, Benjamin Block wrote:
> @@ -518,8 +520,13 @@ static ssize_t remove_store(struct device *dev, struct device_attribute *attr,
>  	if (kstrtoul(buf, 0, &val) < 0)
>  		return -EINVAL;
>  
> -	if (val && device_remove_file_self(dev, attr))
> +	if (val && device_remove_file_self(dev, attr)) {
> +		device_lock(dev);
> +		kill_device(dev);
> +		device_unlock(dev);
> +		device_driver_detach(dev);
>  		pci_stop_and_remove_bus_device_locked(to_pci_dev(dev));
> +	}
>  	return count;
>  }
>  static DEVICE_ATTR_IGNORE_LOCKDEP(remove, 0220, NULL,
> 
> Marking the device dead prevents re-binding after the unbind.

That can also be achieved through the PCI_DEV_ALLOW_BINDING flag,
though you'd have to add a pci_dev_disallow_binding() helper in
drivers/pci/pci.h to go alongside the existing
pci_dev_allow_binding() and pci_dev_binding_disallowed() helpers.

However pci_stop_and_remove_bus_device() implicitly unbinds the
driver before removing the device.  Remind me, what's the need
to unbind before calling that function?

Thanks,

Lukas