Re: [PATCH v2 01/19] xen/x86: remove "depends on !PV_SHIM_EXCLUSIVE"

[Jan Beulich <jbeulich@xxxxxxxx>]

On 29.03.2025 00:56, Stefano Stabellini wrote:
> On Wed, 26 Mar 2025, Penny Zheng wrote:
>> We intend to remove all "depends on !PV_SHIM_EXCLUSIVE" (also the 
>> functionally
>> equivalent "if !...") in Kconfig file, since negative dependancy will badly
>> affect allyesconfig.
>> This commit is based on "x86: provide an inverted Kconfig control for
>> shim-exclusive mode"[1]
>>
>> [1] https://lists.xen.org/archives/html/xen-devel/2023-03/msg00040.html
>>
>> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

Where's this coming from, if I may ask?

>> Signed-off-by: Penny Zheng <Penny.Zheng@xxxxxxx>
>> ---
>>  xen/arch/x86/Kconfig      | 6 ++----
>>  xen/arch/x86/hvm/Kconfig  | 1 -
>>  xen/drivers/video/Kconfig | 4 ++--
>>  3 files changed, 4 insertions(+), 7 deletions(-)
>>
>> diff --git a/xen/arch/x86/Kconfig b/xen/arch/x86/Kconfig
>> index 18efdb2e31..1e5df84b25 100644
>> --- a/xen/arch/x86/Kconfig
>> +++ b/xen/arch/x86/Kconfig
>> @@ -137,7 +137,6 @@ config XEN_IBT
>>  
>>  config SHADOW_PAGING
>>      bool "Shadow Paging"
>> -    default !PV_SHIM_EXCLUSIVE
>>      depends on PV || HVM
>>      help
>>  
>> @@ -169,7 +168,6 @@ config BIGMEM
>>  config TBOOT
>>      bool "Xen tboot support (UNSUPPORTED)"
>>      depends on INTEL && UNSUPPORTED
>> -    default !PV_SHIM_EXCLUSIVE
>>      select CRYPTO
>>      help
>>        Allows support for Trusted Boot using the Intel(R) Trusted Execution
>> @@ -279,10 +277,11 @@ config PV_SHIM_EXCLUSIVE
>>        Build Xen in a way which unconditionally assumes PV_SHIM mode.  This
>>        option is only intended for use when building a dedicated PV Shim
>>        firmware, and will not function correctly in other scenarios.
>> +      Features, like tboot, shadow page, VGA, HVM, Hyper-V Guest, etc,
>> +      are unavailable in shim-exclusive mode.
> 
> I don't know if we want to add these two lines or not. Either way:
> 
> Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>

I don't think we should add that. It's also wrong for shadow in the first
place (where it was a default only anyway, not a dependency).

Jan