Hi Julien and Ayan
On 2023/7/4 20:04, Ayan Kumar Halder wrote:
>
> On 04/07/2023 12:44, Julien Grall wrote:
>> Hi,
>>
>> On 04/07/2023 12:14, Ayan Kumar Halder wrote:
>>> On 26/06/2023 04:33, Penny Zheng wrote:
>>>> CAUTION: This message has originated from an External Source. Please
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>>>>
>>>>
>>>> This commit wants to introduce a new Kconfig CONFIG_HAS_MMU to guard
>>>> MMU-related codes, to tell two different memory management
>>>> architecture:
>>>> VMAS and PMSA.
>>>>
>>>> In a VMSA system, a Memory Management Unit (MMU) provides fine-grained
>>>> control of a memory system through a set of virtual to physical address
>>>> mappings and associated memory properties held in memory-mapped tables
>>>> known as translation tables.
>>>>
>>>> Signed-off-by: Penny Zheng <penny.zheng@arm.com>
>>>> Signed-off-by: Wei Chen <wei.chen@arm.com>
>>>> ---
>>>> v3:
>>>> - new patch
>>>> ---
>>>> xen/arch/arm/Kconfig | 8 ++++++++
>>>> 1 file changed, 8 insertions(+)
>>>>
>>>> diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
>>>> index ff17345cdb..fb77392b82 100644
>>>> --- a/xen/arch/arm/Kconfig
>>>> +++ b/xen/arch/arm/Kconfig
>>>> @@ -60,6 +60,14 @@ config PADDR_BITS
>>>>
>>>> source "arch/Kconfig"
>>>>
>>>> +config HAS_MMU
>>>> + bool "Memory Management Unit support in a VMSA system"
>>>> + default y
>>
>> I don't think you can disable HAS_MMU right now. So you want to drop
>> the description to prevent a user to select it. This could then be
>> combined to
>>
>> "def_bool y".
>>
>>>> + help
>>>> + In a VMSA system, a Memory Management Unit (MMU) provides
>>>> fine-grained control of
>>>> + a memory system through a set of virtual to physical
>>>> address mappings and associated memory
>>>> + properties held in memory-mapped tables known as
>>>> translation tables.
>>>> +
>>>> config ACPI
>>>> bool "ACPI (Advanced Configuration and Power Interface)
>>>> Support (UNSUPPORTED)" if UNSUPPORTED
>>>> depends on ARM_64
>>>
>>> I don't think you need this option.
>>
>> I think we want to introduce a 'choice' where the user can select
>> either the MPU or MMU. But not both.
>
> +1 (I like this approach).
+1 from me
I will introduce the choice "ARM Memory Management Architecture" and
default HAS_MMU
>
>>
>> This would be similar to how we select the Physical address space size.
>>
>> Cheers,
>>