Re: [PATCH 2/4] xen: Drop CONFIG_XEN_PVHVM

On 2026-08-05 04:36, Juergen Gross wrote:
> On 05.08.26 10:28, Andrew Cooper wrote:
>> On 05/08/2026 9:21 am, Juergen Gross wrote:
>>> On x86 CONFIG_XEN_PVHVM is now a synonym of CONFIG_XEN.
>>>
>>> In Xen specific x86 code it can be just dropped, in non-Xen specific
>>> x86 code it can be replaced with CONFIG_XEN.
>>>
>>> In architecture independent code it is used only where CONFIG_XEN is
>>> defined, so it can be replaced with CONFIG_X86 there.
>>>
>>> Signed-off-by: Juergen Gross <[email protected]>
>>>
>>> diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/ 
>>> idtentry.h
>>> index 20f548702404..f400cfac69a6 100644
>>> --- a/arch/x86/include/asm/idtentry.h
>>> +++ b/arch/x86/include/asm/idtentry.h
>>> @@ -745,7 +745,7 @@ 
>>> DECLARE_IDTENTRY_SYSVEC(HYPERV_STIMER0_VECTOR,        
>>> sysvec_hyperv_stimer0);
>>>   DECLARE_IDTENTRY_SYSVEC(HYPERVISOR_CALLBACK_VECTOR,    
>>> sysvec_acrn_hv_callback);
>>>   #endif
>>> -#ifdef CONFIG_XEN_PVHVM
>>> +#ifdef CONFIG_XEN
>>>   DECLARE_IDTENTRY_SYSVEC(HYPERVISOR_CALLBACK_VECTOR,    
>>> sysvec_xen_hvm_callback);
>>>   #endif
>>
>> I'm very happy to see a reduction in the number of Kconfig symbols for
>> Xen (there are definitely too many), but this looks wonky.
>>
>> Or are you saying that there really is no way to build a Xen PV guest
>> excluding the HVM-only bits?
> 
> Seems so, yes.
> 
> This has been like this for at least several years now.
> 
> What you can do is to configure the kernel to exclude the Xen platform PCI
> device (CONFIG_XEN_PVHVM_GUEST=n).
I think I caused this inadvertently in 34aff14580d1 ("xen: Remove Xen 
PVH/PVHVM dependency on PCI")

CONFIG_XEN_PVHVM should just be bool, and then XEN_PVH & XEN_PVHVM_GUEST 
can select it.  Then it can be disabled for a PV only build.

I'll send it out, so you can evaluate it.

Regards,
Jason