Re: [PATCH v3 3/3] x86/mce: Add CMCI storm switching support for Zhaoxin

[Tony W Wang-oc]

On 2024/9/20 17:17, Zhuo, Qiuxu wrote:
> > From: Tony W Wang-oc <TonyWWang-oc@xxxxxxxxxxx>
> > [...]
> > Subject: [PATCH v3 3/3] x86/mce: Add CMCI storm switching support for
> > [...]
> > --- a/arch/x86/kernel/cpu/mce/zhaoxin.c
> > +++ b/arch/x86/kernel/cpu/mce/zhaoxin.c
> > @@ -63,3 +63,21 @@ void mce_zhaoxin_feature_clear(struct cpuinfo_x86 *c)
> > {
> >        intel_clear_lmce();
> >   }
> > +
> > +void mce_zhaoxin_handle_storm(int bank, bool on) {
> > +     unsigned long flags;
> > +     u64 val;
> > +
> > +     raw_spin_lock_irqsave(&cmci_discover_lock, flags);
> > +     rdmsrl(MSR_IA32_MCx_CTL2(bank), val);
> > +     if (on) {
> > +             val &= ~(MCI_CTL2_CMCI_EN |
> > MCI_CTL2_CMCI_THRESHOLD_MASK);
> > +             val |= CMCI_STORM_THRESHOLD;
> > +     } else {
> > +             val &= ~MCI_CTL2_CMCI_THRESHOLD_MASK;
> > +             val |= (MCI_CTL2_CMCI_EN | cmci_threshold[bank]);
> > +     }
> > +     wrmsrl(MSR_IA32_MCx_CTL2(bank), val);
> > +     raw_spin_unlock_irqrestore(&cmci_discover_lock, flags); }
>
> Are there any reasons or comments why it needs to disable/enable the CMCI interrupt
> here during a CMCI storm on/off? If not, then reuse mce_intel_handle_storm() to avoid
> duplicating the code.

As explained in another email.
The reason is actually mentioned in the cover letter: "because Zhaoxin's 
UCR error is not reported through CMCI", and we want to disable CMCI 
interrupt when CMCI storm happened.

Sincerely
TonyWWang-oc