Re: [PATCH] xen: Kconfig: Drop reference to obsolete configs MCORE2 and MK8

[Arnd Bergmann]

On Mon, Mar 3, 2025, at 10:37, Lukas Bulwahn wrote:
> From: Lukas Bulwahn <lukas.bulwahn@xxxxxxxxxx>
>
> Commit f388f60ca904 ("x86/cpu: Drop configuration options for early 64-bit
> CPUs") removes the config symbols MCORE2 and MK8.
>
> With that, the references to those two config symbols in xen's x86 Kconfig
> are obsolete. Drop them.
>
> Signed-off-by: Lukas Bulwahn <lukas.bulwahn@xxxxxxxxxx>

Good catch!

> diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
> index 77e788e928cd..98d8a50d2aed 100644
> --- a/arch/x86/xen/Kconfig
> +++ b/arch/x86/xen/Kconfig
> @@ -9,7 +9,7 @@ config XEN
>  	select PARAVIRT_CLOCK
>  	select X86_HV_CALLBACK_VECTOR
>  	depends on X86_64 || (X86_32 && X86_PAE)
> -	depends on X86_64 || (X86_GENERIC || MPENTIUM4 || MCORE2 || MATOM || MK8)
> +	depends on X86_64 || (X86_GENERIC || MPENTIUM4 || MATOM)
>  	depends on X86_LOCAL_APIC && X86_TSC
>  	help
>  	  This is the Linux Xen port.  Enabling this will allow the

I suspect some or all all of the other three options should be
dropped as well, given that 32-bit XEN_PV guests are already
unsupported as of

commit a13f2ef168cb2a033a284eb841bcc481ffbc90cf
Author: Juergen Gross <jgross@xxxxxxxx>
Date:   Mon Jun 29 10:35:39 2020 +0200

    x86/xen: remove 32-bit Xen PV guest support
    
    Xen is requiring 64-bit machines today and since Xen 4.14 it can be
    built without 32-bit PV guest support. There is no need to carry the
    burden of 32-bit PV guest support in the kernel any longer, as new
    guests can be either HVM or PVH, or they can use a 64 bit kernel.
    
    Remove the 32-bit Xen PV support from the kernel.

and 32-bit Pentium4 and Atom CPUs don't run modern Xen hosts.
Most likely this should be

   depends on X86_64 || (X86_32 && X86_PAE && X86_GENERIC)

to say that running 32-bit XEN_PVHVM guests is still supported
allowed on 64-bit hosts, but not on pure 32-bit machines.

    Arnd