:orphan:

.. title:: X86_KPTI

.. option:: CONFIG_X86_KPTI

*Enable kernel page table isolation*

Type: ``bool``

Help
====

Implements kernel page table isolation to mitigate Meltdown exploits
to read Kernel RAM. Incurs a significant performance cost for
user thread interrupts and system calls, and significant footprint
increase for additional page tables and trampoline stacks.

Direct dependencies
===================

\ :option:`USERSPACE <CONFIG_USERSPACE>` && !\ :option:`X86_NO_MELTDOWN <CONFIG_X86_NO_MELTDOWN>` && \ :option:`X86 <CONFIG_X86>`

*(Includes any dependencies from ifs and menus.)*

Default
=======

- y

Kconfig definition
==================

.. highlight:: kconfig

At ``arch/x86/Kconfig:308``

Included via ``Kconfig:8`` → ``Kconfig.zephyr:29`` → ``arch/Kconfig:12``

Menu path: (Top) → X86 Architecture Options

.. parsed-literal::

    config X86_KPTI
    	bool "Enable kernel page table isolation"
    	default y
    	depends on \ :option:`USERSPACE <CONFIG_USERSPACE>` && !\ :option:`X86_NO_MELTDOWN <CONFIG_X86_NO_MELTDOWN>` && \ :option:`X86 <CONFIG_X86>`
    	help
    	  Implements kernel page table isolation to mitigate Meltdown exploits
    	  to read Kernel RAM. Incurs a significant performance cost for
    	  user thread interrupts and system calls, and significant footprint
    	  increase for additional page tables and trampoline stacks.

*(The 'depends on' condition includes propagated dependencies from ifs and menus.)*