Re: [PATCH v2 2/8] vpci/header: Emulate legacy capability list for host

[Jan Beulich <jbeulich@xxxxxxxx>]

On 15.04.2025 12:07, Chen, Jiqian wrote:
> On 2025/4/15 17:25, Roger Pau Monné wrote:
>> On Wed, Apr 09, 2025 at 02:45:22PM +0800, Jiqian Chen wrote:
>>> --- a/xen/drivers/vpci/header.c
>>> +++ b/xen/drivers/vpci/header.c
>>> @@ -745,6 +745,76 @@ static int bar_add_rangeset(const struct pci_dev 
>>> *pdev, struct vpci_bar *bar,
>>>      return !bar->mem ? -ENOMEM : 0;
>>>  }
>>>  
>>> +/* These capabilities can be exposed to the guest, that vPCI can handle. */
>>> +static const unsigned int guest_supported_caps[] = {
>>> +    PCI_CAP_ID_MSI,
>>> +    PCI_CAP_ID_MSIX,
>>> +};
>>
>> Is there a reason this needs to be defined outside of the function
>> scope?  So far it's only used by vpci_init_capability_list().
> Because, for dom0 I don't need to pass this array, so I need to set below 
> parameter "caps" to be NULL or guest_supported_caps according to the type of 
> domain.
> If inside the function, I can't to do that since "caps" is const, I think.

Why would the more narrow scope of the array affect how it can be used?

Jan