Re: [PATCH v4 0/3] driver core: add TAINT_FORCED_BIND for when userspace manually messes with devices and drivers

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Mon, Oct 26, 2026 at 03:43:12PM -0300, Jason Gunthorpe wrote:
> On Mon, Oct 26, 2026 at 02:22:43PM +0200, Leon Romanovsky wrote:
> 
> > This is needed for two reasons: to save hardware and software resources
> > when creating a large number of VFs, and to allow the PCI config space to
> > be configured *before* the driver starts using it.
> > 
> > There is no in-kernel alternative.
> 
> Having userspace involved in driver binding has also always been the
> plan for confidential computing needs. We cannot have a device driver
> bound across some of the HW transitions like TDISP shared/private, so
> there has always been an expectation of bind/unbind.

What, why?  What forces that decision?  What's wrong with the proper
driver for the hardware being bound automatically to the device?

> For this case the existing sysf drivers_probe is good enough for bind,
> but we must have taint-free unbind for PCI devices too.

Why?

> I think this patch should be reverted ASAP, it is a pretty major
> regression for a lot of users.

But this use case hasn't even happened yet, so what would regress?

I'm not talking about the vfio thing, that's different here...

thanks,

greg k-h