Re: [PATCH v2 4/4] x86: adjustments to guest handle treatment

[Julien Grall <julien@xxxxxxx>]

Hi Jan,

On 21/04/2020 10:13, Jan Beulich wrote:
> First of all avoid excessive conversions. copy_{from,to}_guest(), for
> example, work fine with all of XEN_GUEST_HANDLE{,_64,_PARAM}().
>
> Further
> - do_physdev_op_compat() didn't use the param form for its parameter,
> - {hap,shadow}_track_dirty_vram() wrongly used the param form,
> - compat processor Px logic failed to check compatibility of native and
>    compat structures not further converted.
>
> As this eliminates all users of guest_handle_from_param() and as there's
> no real need to allow for conversions in both directions, drop the
> macros as well.
I was kind of expecting both guest_handle_from_param() and 
guest_handle_to_param() to be dropped together. May I ask why you still 
need guest_handle_to_param()?
[...]

>   /* Handler for shadow control ops: operations from user-space to enable
>    * and disable ephemeral shadow modes (test mode and log-dirty mode) and
> --- a/xen/include/xen/acpi.h
> +++ b/xen/include/xen/acpi.h
> @@ -184,8 +184,8 @@ static inline unsigned int acpi_get_csub
>   static inline void acpi_set_csubstate_limit(unsigned int new_limit) { return; 
> }
>   #endif
>   
> -#ifdef XEN_GUEST_HANDLE_PARAM
> -int acpi_set_pdc_bits(u32 acpi_id, XEN_GUEST_HANDLE_PARAM(uint32));
> +#ifdef XEN_GUEST_HANDLE
> +int acpi_set_pdc_bits(u32 acpi_id, XEN_GUEST_HANDLE(uint32));
>   #endif
Do we really need to keep the #ifdef here?

>   int arch_acpi_set_pdc_bits(u32 acpi_id, u32 *, u32 mask);
>   
Cheers,

--
Julien Grall