This time it could be an AVX512 instruction (intel only) that leaks kernel address in a way or another.
I was talking from an ISA perspective. For eg, clflush may be implemented differently between Intel and AMD, it has the same effect on system RAM hence a shared exploit.
No, rowhammer does not need clflush. All rowhammer needs is to be able to write to the same physical memory locations repeatedly. Normally the cache would get in the way, so the attacker needs to bypass it. Flushing the cache (clflush) is one way, but there are others; AFAIK, it has been demonstrated rowhammer from within a Javascript VM, which has no access to clflush.
I just made a bet that I could guess something out of ISA only. Going macro to describe what may be the issue. I'm just doing a guess work here.
I was not implying Intel has the same implementation as AMD, nor I was making a case for "this is like rowhammer"