Re: retbleed on hygon

[Peter Zijlstra]

On Mon, Jul 18, 2022 at 01:03:41PM +0000, Wen Pu wrote:
> On 2022/7/18 19:44, Peter Zijlstra wrote:
> > Hi Pu Wen,
> > 
> > Now that retbleed is public could you please review the patches in
> > question and clarify the situation vs Hygon please? For development I've
> > assumed Hygon is basically Zen1 wrt this issue.
> 
> Hi Peter,
> 
> I'm sorry that there is something wrong with my email these days, so I
> haven't received the patches. Do you mean those with "[peterz: add
> hygon]" added by you? Thanks a lot for taking Hygon into account. I'll
> clarify it as soon as possible.

It's not your email, it was a hardware embargo issue so these patches
have never been mailed out before hitting Linus' tree :-/

Please double check the entire series, see the merge commit:

  ce114c866860 ("Merge tag 'x86_bugs_retbleed' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip")

But in specific pay attention to commits:

  a149180fbcf336e97ce4eb2cdc13672727feb94d
  6b80b59b3555706508008f1f127b5412c89c7fd8
  3ebc170068885b6fc7bedda6c667bb2c4d533159
  d7caac991feeef1b871ee6988fd2c9725df09039
  26aae8ccbc1972233afd08fb3f368947c0314265

Basically everything that has HYGON in it. For that first commit, double
check with your hardware folks the mitigation actually works for Hygon
too. For the other commits validate it DTRT wrt HYGON. Please also send
a patch enabling or removing the spectral chicken for hygon.