Re: [PATCH v4 15/21] x86/resctrl: Abstract __rmid_read()

[Reinette Chatre <reinette.chatre@intel.com>]

Hi James,

On 4/12/2022 5:44 AM, James Morse wrote:

> @@ -180,14 +180,24 @@ static u64 __rmid_read(u32 rmid, enum resctrl_event_id eventid)
>  	 * are error bits.
>  	 */
>  	wrmsr(MSR_IA32_QM_EVTSEL, eventid, rmid);
> -	rdmsrl(MSR_IA32_QM_CTR, val);
> +	rdmsrl(MSR_IA32_QM_CTR, msr_val);
>  
> -	return val;
> +	if (msr_val & RMID_VAL_ERROR)
> +		return -EIO;
> +	if (msr_val & RMID_VAL_UNAVAIL)
> +		return -EINVAL;
> +
> +	*val = msr_val;
> +
> +	return 0;
>  }
>  

In above EIO is used to represent RMID_VAL_ERROR ...

> @@ -343,7 +355,7 @@ static u64 __mon_event_count(u32 rmid, struct rmid_read *rr)
>  		 * Code would never reach here because an invalid
>  		 * event id would fail the __rmid_read.
>  		 */
> -		return RMID_VAL_ERROR;
> +		return -EINVAL;
>  	}
>  
>  	if (rr->first) {

I understand it can be seen as a symbolic change but could
RMID_VAL_ERROR consistently be associated with the same error?

Reinette