Re: [PATCH] x86/perf/zhaoxin: Add stepping check for ZX-C

[silviazhaooc]

Hi Boris,

Thanks for your reply.

As I mentioned before, Nano has several series. We cannot test if all of 
them have the bug. Besides, AFAIK Nano's hardware support for PMC has 
not externally announced. So setting a new X86_BUG_ flag to Nano is 
inappropriate.

I still think exclude PMC support in driver is more appropriate.

Looking forward to your comments.


On 2023/2/6 17:48, Borislav Petkov wrote:
> On Mon, Feb 06, 2023 at 04:26:25PM +0800, silviazhaooc wrote:
> > Due to our company’s email policy, email address with oc suffix is used for
> > sending email without confidentiality statement at the end of the mail body.
> >
> > I will remove –oc from my name later.
>
> Yes, please. The email address is fine but the name doesn't have to have
> that funky "-oc" thing.
>
> > But due to some unknown historical reasons, the FMS of Nano and ZXC are only
> > different in stepping.
> >
> > I have considered about using the “Model name string” to distinguish them,
> > but it doesn't seem to be a common way in Linux kernel.
>
> I don't mind you using steppings to differentiate the two as long as
> this is not going to change all of a sudden and that differentiation is
> unambiguous.
>
> If not, you will have to use name strings as you don't have any other
> choice.
>
> Whatever you do, pls define a new X86_BUG_ flag, set it only on Nano and
> then test it in the PMU init code.
>
> Thx.