Re: [PATCH v2 09/11] xen/riscv: introduce p2m_gpa_bits

[Oleksii Kurochko <oleksii.kurochko@gmail.com>]

On 4/1/26 8:07 AM, Jan Beulich wrote:
>>>> @@ -191,8 +209,13 @@ static void __init gstage_mode_detect(void)
>>>>    
>>>>    void __init guest_mm_init(void)
>>>>    {
>>>> +    unsigned int gpa_bits;
>>>> +    unsigned int paging_levels = default_gstage_mode.paging_levels;
>>> Deriving a global from a default, when ...
>>>
>>>>        gstage_mode_detect();
>>>>    
>>>> +    ASSERT(default_gstage_mode.paging_levels <= max_gstage_mode.paging_levels);
>>> ... the default isn't the maximum possible, isn't going to fly.
>> I didn't get you here.
>>
>> If we want Xen uses Sv39 for G-stage, we want to limit guest's 56-bit
>> GPA to 39-bit GPA, but not the maximum supported by h/w mode for G-stage
>> mode.
> I can only repeat what I thought I had got across already on an earlier
> series of yours: What mode a guest is going to use is going to be a guest
> property. The default mode therefore isn't the only mode that may be used
> at runtime.

I remember that, but i don't really understand what is wrong now with 
the ASSERT(). It should be changed or dropped at all when this property 
you are talking about will be introduced.

~ Oleksii