Re: [PATCH] x86/speculation: Add document to describe Spectre and its mitigations

[Jiri Kosina]

On Mon, 14 Jan 2019, Pavel Machek wrote:

> Frankly I'd not call it Meltdown, as it works only on data in the cache, 
> so the defense is completely different. Seems more like a l1tf
> :-).

Meltdown on x86 also seems to work only for data in L1D, but the pipeline 
could be constructed in a way that data are actually fetched into L1D 
before speculation gives up, which is not the case on ppc (speculation 
aborts on L2->L1 propagation IIRC). That's why flushing L1D on ppc is 
sufficient, but on x86 it's not.

-- 
Jiri Kosina
SUSE Labs