Quoting Renaud (Ron) OLGIATI (renaud@???):

> ISTR that AMDs are not affected by Meltdown, but affected by Spectre

_Possibly_. Quoting the Meltdown FAQ: 'At the moment, it is unclear
whether ARM and AMD processors are also affected by Meltdown.'
https://meltdownattack.com/#faq

Section 6.4 of the Meltdown research paper gives details:

We also tried to reproduce the Meltdown bug on several ARM and AMD
CPUs. However, we did not manage to successfully leak kernel memory
with the attack described in Section 5, neither on ARM nor on AMD.
The reasons for this can be manifold. First of all, our implementation
might simply be too slow and a more optimized version might succeed.
For instance, a more shallow out-of-order execution pipeline could tip
the race condition towards against the data leakage. Similarly, if
the processor lacks certain features, e.g., no re-order buffer, our
current implementation might not be able to leak data. However, for
both ARM and AMD, the toy example as described in Section 3 works
reliably, indicating that out-of-order execution generally occurs and
instructions past illegal memory accesses are also performed.

https://meltdownattack.com/meltdown.pdf