Re: [PATCH v2] hw/i386: place setup_data at fixed place in memory

[Jason A. Donenfeld]

Hi Daniel,

On Thu, Aug 04, 2022 at 10:25:36AM +0100, Daniel P. Berrangé wrote:
> Yep, and ultimately the inability to distinguish UEFI vs other firmware
> is arguably correct by design, as the QEMU <-> firmware interface is
> supposed to be arbitrarily pluggable for any firmware implementation
> not  limited to merely UEFI + seabios.

Indeed, I agree with this.

> 
> > For now I suggest either reverting the original patch, or at least not
> > enabling the knob by default for any machine types. In particular, when
> > using MicroVM, the user must leave the knob disabled when direct booting
> > a kernel on OVMF, and the user may or may not enable the knob when
> > direct booting a kernel on SeaBIOS.
> 
> Having it opt-in via a knob would defeat Jason's goal of having the seed
> available automatically.

Yes, adding a knob is absolutely out of the question.

It also doesn't actually solve the problem: this triggers when QEMU
passes a DTB too. It's not just for the new RNG seed thing. This bug
isn't new.

Jason