Re: [PATCH 4/4] x86/xen: Drop CONFIG_XEN_PVHVM_SMP

On 05.08.2026 10:55, Juergen Gross wrote:
> On 05.08.26 10:44, Jan Beulich wrote:
>> On 05.08.2026 10:21, Juergen Gross wrote:
>>> --- a/arch/x86/xen/Makefile
>>> +++ b/arch/x86/xen/Makefile
>>> @@ -37,8 +37,8 @@ obj-$(CONFIG_XEN_PVH)		+= enlighten_pvh.o
>>>   obj-$(CONFIG_EVENT_TRACING)	+= trace.o
>>>   
>>>   obj-$(CONFIG_SMP)		+= smp.o
>>> +obj-$(CONFIG_SMP)		+= smp_hvm.o
>>>   obj-$(CONFIG_XEN_PV_SMP)  	+= smp_pv.o
>>> -obj-$(CONFIG_XEN_PVHVM_SMP)  	+= smp_hvm.o
>>
>> Similar issue here - in a PV-only config smp_hvm.o doesn't want / shouldn't
>> need building.
> 
> Note that I didn't change any functionality.
> 
> I agree that it seems a little bit strange, but in the end I believe
> the current status is okay-ish. PV-only hasn't been something in upstream
> Linux since Xen support was added, as PV was always meant to be an
> alternative to bare metal support via paravirt patching. It might have
> been possible to build a kernel not really functional on bare metal, but
> this was more like the ability to build a x86 kernel not working on any
> existing machine.
> 
> IMO the Xen kernel config options should allow for adding Xen-specific
> features, but minimum Xen support should always have basic HVM support,
> which includes the Xen specific performance enhancements.

I fear I don't understand this. If I want a kernel just to run as PV Dom0,
why would it need to carry anything HVM-ish? That is (or should be)
entirely unrelated to being able to also run this same kernel on baremetal
then.

Jan