Re: [PATCH v4] virt: vmgenid: introduce driver for reinitializing RNG on VM fork

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Feb 25, 2022 at 02:57:38PM +0100, Alexander Graf wrote:
> > +
> > +       phys_addr = (obj->package.elements[0].integer.value << 0) |
> > +                   (obj->package.elements[1].integer.value << 32);
> > +       state->next_id = devm_memremap(&device->dev, phys_addr, VMGENID_SIZE, MEMREMAP_WB);
> > +       if (!state->next_id) {
> > +               ret = -ENOMEM;
> > +               goto out;
> > +       }
> > +
> > +       memcpy(state->this_id, state->next_id, sizeof(state->this_id));
> > +       add_device_randomness(state->this_id, sizeof(state->this_id));
> 
> 
> Please expose the vmgenid via /sysfs so that user space even remotely has a
> chance to check if it's been cloned.

Export it how?  And why, who would care?

thanks,

greg k-h