Re: [PATCH v3 03/11] vpci/header: Emulate legacy capability list for dom0

["Chen, Jiqian" <Jiqian.Chen@xxxxxxx>]

On 2025/5/6 21:50, Roger Pau Monné wrote:
> On Mon, Apr 21, 2025 at 02:18:55PM +0800, Jiqian Chen wrote:
>> Current logic of emulating legacy capability list is only for domU.
>> So, expand it to emulate for dom0 too. Then it will be easy to hide
>> a capability whose initialization fails in a function.
>>
>> Signed-off-by: Jiqian Chen <Jiqian.Chen@xxxxxxx>
> 
> Sorry, one nit I've noticed while looking at the next patch.
> 
>> @@ -786,13 +787,15 @@ static int vpci_init_capability_list(struct pci_dev 
>> *pdev)
>>  
>>              next = pci_find_next_cap_ttl(pdev->sbdf,
>>                                           pos + PCI_CAP_LIST_NEXT,
>> -                                         supported_caps,
>> -                                         ARRAY_SIZE(supported_caps), &ttl);
>> +                                         caps, n, &ttl);
>>  
>> -            rc = vpci_add_register(pdev->vpci, vpci_hw_read8, NULL,
The same here, NULL -> vpci_hw_write8, I think.

>> -                                   pos + PCI_CAP_LIST_ID, 1, NULL);
>> -            if ( rc )
>> -                return rc;
>> +            if ( !is_hwdom )
>> +            {
>> +                rc = vpci_add_register(pdev->vpci, vpci_hw_read8, NULL,
>> +                                       pos + PCI_CAP_LIST_ID, 1, NULL);
>> +                if ( rc )
>> +                    return rc;
>> +            }
>>  
>>              rc = vpci_add_register(pdev->vpci, vpci_read_val, NULL,
> 
> For the hardware domain the write handler should be vpci_hw_write8
> instead of NULL.
OK, I think I need to add definition of vpci_hw_write8.
But I have a question, if hardware domain write this register through 
vpci_hw_write8,
then the "next address data" of hardware will be in consistent with vpci.
Is it fine? Or should I update vpci's cache?

> 
> Thanks, Roger.

-- 
Best regards,
Jiqian Chen.