Re: [PATCH v7 11/12] xen/arm: add sve property for dom0less domUs

[Michal Orzel <michal.orzel@xxxxxxx>]

Hi Luca,

Sorry for jumping into this but I just wanted to read the dt binding doc and 
spotted one thing by accident.

On 24/05/2023 17:20, Bertrand Marquis wrote:
> 
> 
> Hi Luca,
> 
>> On 23 May 2023, at 09:43, Luca Fancellu <Luca.Fancellu@xxxxxxx> wrote:
>>
>> Add a device tree property in the dom0less domU configuration
>> to enable the guest to use SVE.
>>
>> Update documentation.
>>
>> Signed-off-by: Luca Fancellu <luca.fancellu@xxxxxxx>
> 
> Reviewed-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>

(...)
>> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
>> index 9202a96d9c28..ba4fe9e165ee 100644
>> --- a/xen/arch/arm/domain_build.c
>> +++ b/xen/arch/arm/domain_build.c
>> @@ -4008,6 +4008,34 @@ void __init create_domUs(void)
>>             d_cfg.max_maptrack_frames = val;
>>         }
>>
>> +        if ( dt_get_property(node, "sve", &val) )
>> +        {
>> +#ifdef CONFIG_ARM64_SVE
>> +            unsigned int sve_vl_bits;
>> +            bool ret = false;
>> +
>> +            if ( !val )
>> +            {
>> +                /* Property found with no value, means max HW VL supported 
>> */
>> +                ret = sve_domctl_vl_param(-1, &sve_vl_bits);
>> +            }
>> +            else
>> +            {
>> +                if ( dt_property_read_u32(node, "sve", &val) )
>> +                    ret = sve_domctl_vl_param(val, &sve_vl_bits);
>> +                else
>> +                    panic("Error reading 'sve' property");
Both here and ...

>> +            }
>> +
>> +            if ( ret )
>> +                d_cfg.arch.sve_vl = sve_encode_vl(sve_vl_bits);
>> +            else
>> +                panic("SVE vector length error\n");
>> +#else
>> +            panic("'sve' property found, but CONFIG_ARM64_SVE not 
>> selected");
here you are missing \n at the end of string. If you take a look at panic() 
implementation,
new line char is not added so in your case it would result in an ugly formatted 
panic message.

~Michal