Re: [PATCH 08/10] arm: allwinner-h3: add Security Identifier device

[Philippe Mathieu-Daudé]

On 12/6/19 3:27 PM, Peter Maydell wrote:
> On Mon, 2 Dec 2019 at 21:10, Niek Linnenbank <address@hidden> wrote:
> > The Security Identifier device in Allwinner H3 System on Chip
> > gives applications a per-board unique identifier. This commit
> > adds support for the Allwinner H3 Security Identifier using
> > randomized data as input.
>
> If this is a fixed value in hardware, I'm not sure that
> having the QEMU model pick a random value is the best
> choice. If we just set it to a fixed value in QEMU, is
> that going to cause problems?
>
> (Generally it's nice for QEMU to be deterministic, so it
> behaves the same way every time you run it. Also if it's
> always the same we don't need to bother migrating the
> ID value.)

Agreed. Since the identifier is 128-bit, I'd use DEFINE_PROP_UUID() or, 
to be even safer, DEFINE_PROP_UUID_NODEFAULT().
See how the ipmi-bmc-sim device checks its guid field and fails if unset.