Re: [PATCH hyperv-next v5 03/11] Drivers: hv: Enable VTL mode for arm64

[Roman Kisel <romank@linux.microsoft.com>]

On 3/8/2025 1:05 PM, Arnd Bergmann wrote:
> On Fri, Mar 7, 2025, at 23:02, Roman Kisel wrote:
>> @@ -5,18 +5,20 @@ menu "Microsoft Hyper-V guest support"
>>   config HYPERV
>>   	tristate "Microsoft Hyper-V client drivers"
>>   	depends on (X86 && X86_LOCAL_APIC && HYPERVISOR_GUEST) \
>> -		|| (ACPI && ARM64 && !CPU_BIG_ENDIAN)
>> +		|| (ARM64 && !CPU_BIG_ENDIAN)
>> +	depends on (ACPI || HYPERV_VTL_MODE)
>>   	select PARAVIRT
>>   	select X86_HV_CALLBACK_VECTOR if X86
>> -	select OF_EARLY_FLATTREE if OF
>>   	help
>>   	  Select this option to run Linux as a Hyper-V client operating
>>   	  system.
>>
>>   config HYPERV_VTL_MODE
>>   	bool "Enable Linux to boot in VTL context"
>> -	depends on X86_64 && HYPERV
>> +	depends on (X86_64 || ARM64)
>>   	depends on SMP
>> +	select OF_EARLY_FLATTREE
>> +	select OF
>>   	default n
>>   	help
> 
> Having the dependency below the top-level Kconfig entry feels a little
> counterintuitive. You could flip that back as it was before by doing
> 
>        select HYPERV_VTL_MODE if !ACPI
>        depends on ACPI || SMP
> 
> in the HYPERV option, leaving the dependency on HYPERV in
> HYPERV_VTL_MODE.
> 

I was implementing Michael's suggestion, and might've gone a bit
overboard, my bad. I'll fix this, thanks a lot for reviewing!

> Is OF_EARLY_FLATTREE actually needed on x86?
> 

No, it is not needed on x86. It is only needed when VTL mode is used.

>        Arnd

-- 
Thank you,
Roman