Re: [PATCH v3 1/2] xen-pciback: prepare for the split for stub and PV

From: Oleksandr Andrushchenko
Date: Thu Sep 23 2021 - 07:13:47 EST



On 23.09.21 14:10, Jan Beulich wrote:
> On 23.09.2021 11:53, Oleksandr Andrushchenko wrote:
>> --- a/drivers/xen/Kconfig
>> +++ b/drivers/xen/Kconfig
>> @@ -180,10 +180,34 @@ config SWIOTLB_XEN
>> select DMA_OPS
>> select SWIOTLB
>>
>> +config XEN_PCI_STUB
>> + bool
>> +
>> +config XEN_PCIDEV_STUB
>> + tristate "Xen PCI-device stub driver"
>> + depends on PCI && !X86 && XEN
>> + depends on XEN_BACKEND
>> + select XEN_PCI_STUB
>> + default m
>> + help
>> + The PCI device stub driver provides limited version of the PCI
>> + device backend driver without para-virtualized support for guests.
>> + If you select this to be a module, you will need to make sure no
>> + other driver has bound to the device(s) you want to make visible to
>> + other guests.
>> +
>> + The "hide" parameter (only applicable if backend driver is compiled
>> + into the kernel) allows you to bind the PCI devices to this module
>> + from the default device drivers. The argument is the list of PCI BDFs:
>> + xen-pciback.hide=(03:00.0)(04:00.0)
>> +
>> + If in doubt, say m.
>> +
>> config XEN_PCIDEV_BACKEND
>> tristate "Xen PCI-device backend driver"
>> depends on PCI && X86 && XEN
>> depends on XEN_BACKEND
>> + select XEN_PCI_STUB
> Does kconfig not at least warn about this? The selected item has a
> "depends on !X88" conflicting with the "depends on X86" here.

Why?

XEN_PCIDEV_STUB depends on PCI && !X86 && XEN

XEN_PCI_STUB has nothing, just bool

XEN_PCIDEV_BACKEND selects XEN_PCI_STUB

>
> Jan
>