Re: [PATCH v5 08/10] xen: Split HAS_DEVICE_TREE in two

[Jan Beulich <jbeulich@xxxxxxxx>]

On 01.07.2025 12:57, Alejandro Vallejo wrote:
> @@ -85,7 +86,11 @@ config HAS_ALTERNATIVE
>  config HAS_COMPAT
>       bool
>  
> -config HAS_DEVICE_TREE
> +config HAS_DEVICE_TREE_DISCOVERY
> +     bool
> +     select DEVICE_TREE_PARSE
> +
> +config DEVICE_TREE_PARSE
>       bool
>       select LIBFDT
>  

We're in the middle of various ([almost] alphabetically sorted) HAS_* here.
Thus DEVICE_TREE_PARSE wants to move elsewhere. Or we want to move back to
naming it HAS_DEVICE_TREE_PARSE, but I think there was a reason why we didn't
want it like that? Just that I don't recall what that reason was ...

> --- a/xen/common/sched/Kconfig
> +++ b/xen/common/sched/Kconfig
> @@ -67,7 +67,7 @@ endmenu
>  
>  config BOOT_TIME_CPUPOOLS
>       bool "Create cpupools at boot time"
> -     depends on HAS_DEVICE_TREE
> +     depends on HAS_DEVICE_TREE_DISCOVERY

Is this correct? CPU pool creation isn't driven by DT discovery, I thought,
but is a software-only thing much like dom0less?

> --- a/xen/include/xsm/dummy.h
> +++ b/xen/include/xsm/dummy.h
> @@ -423,7 +423,7 @@ static XSM_INLINE int cf_check xsm_deassign_device(
>  
>  #endif /* HAS_PASSTHROUGH && HAS_PCI */
>  
> -#if defined(CONFIG_HAS_PASSTHROUGH) && defined(CONFIG_HAS_DEVICE_TREE)
> +#if defined(CONFIG_HAS_PASSTHROUGH) && 
> defined(CONFIG_HAS_DEVICE_TREE_DISCOVERY)
>  static XSM_INLINE int cf_check xsm_assign_dtdevice(
>      XSM_DEFAULT_ARG struct domain *d, const char *dtpath)
>  {
> @@ -438,7 +438,7 @@ static XSM_INLINE int cf_check xsm_deassign_dtdevice(
>      return xsm_default_action(action, current->domain, d);
>  }
>  
> -#endif /* HAS_PASSTHROUGH && HAS_DEVICE_TREE */
> +#endif /* HAS_PASSTHROUGH && HAS_DEVICE_TREE_DISCOVERY */

Here I'm similarly unsure: Pass-through again isn't a platform thing, is it?

> @@ -789,7 +789,7 @@ int xsm_multiboot_policy_init(
>      struct boot_info *bi, void **policy_buffer, size_t *policy_size);
>  #endif
>  
> -#ifdef CONFIG_HAS_DEVICE_TREE
> +#ifdef CONFIG_HAS_DEVICE_TREE_DISCOVERY
>  /*
>   * Initialize XSM
>   *
> @@ -839,7 +839,7 @@ static inline int xsm_multiboot_init(struct boot_info *bi)
>  }
>  #endif
>  
> -#ifdef CONFIG_HAS_DEVICE_TREE
> +#ifdef CONFIG_HAS_DEVICE_TREE_DISCOVERY
>  static inline int xsm_dt_init(void)
>  {
>      return 0;
> @@ -849,7 +849,7 @@ static inline bool has_xsm_magic(paddr_t start)
>  {
>      return false;
>  }
> -#endif /* CONFIG_HAS_DEVICE_TREE */
> +#endif /* CONFIG_HAS_DEVICE_TREE_DISCOVERY */

The situation is yet less clear to me here.

Jan