Re: [PATCH v2] SUPPORT.md: Un-shimmed 32-bit PV guests are no longer supported

[Jan Beulich <jbeulich@xxxxxxxx>]

On 06.05.2021 14:47, George Dunlap wrote:
> --- a/xen/arch/x86/Kconfig
> +++ b/xen/arch/x86/Kconfig
> @@ -55,7 +55,7 @@ config PV
>  config PV32
>       bool "Support for 32bit PV guests"
>       depends on PV
> -     default y
> +     default PV_SHIM
>       select COMPAT
>       ---help---
>         The 32bit PV ABI uses Ring1, an area of the x86 architecture which
> @@ -67,7 +67,10 @@ config PV32
>         reduction, or performance reasons.  Backwards compatibility can be
>         provided via the PV Shim mechanism.
>  
> -       If unsure, say Y.
> +       Note that outside of PV Shim, 32-bit PV guests are not security
> +       supported anymore.
> +
> +       If unsure, use the default setting.

Alongside this I wonder whether we should also default opt_pv32 to false
then, unless running in shim mode.

Jan