[PATCH v6 7/7] um: Add 4 level page table support

Johannes Berg johannes at sipsolutions.net
Wed Jul 3 04:32:58 PDT 2024


On Wed, 2024-06-26 at 15:53 +0200, Benjamin Berg wrote:
> 
> +choice
> +	prompt "Pagetable levels"
> +	default 2_LEVEL_PGTABLES if !64BIT
> +	default 4_LEVEL_PGTABLES if 64BIT
> +
> +	config 2_LEVEL_PGTABLES
> +		bool "Two-level pagetables" if !64BIT
> +		depends on !64BIT
> +		help
> +		  Two-level page table for 32-bit architectures.
> +
> +	config 3_LEVEL_PGTABLES
> +		bool "Three-level pagetables" if 64BIT
> +		help
> +		  Three-level pagetables will let UML have more than 4G of physical
> +		  memory.  All the memory that can't be mapped directly will be treated
> +		  as high memory.
> +
> +		  However, this it experimental on 32-bit architectures, so if unsure say
> +		  N (on x86-64 it's automatically enabled, instead, as it's safe there).

You copied this but it's not actually true any more - three-level is
never default now.

johannes




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