v3: * Fixed a Gitlab CI breakage on older toolchains (patch 1) * Removed XD_DISABLE override logic from cpu/intel.c * Various style fixes to patch 2 (from Andrew's feedback)
This option hardens Xen by forcing it to write secure (NX-enhanced) PTEs regardless of the runtime NX feature bit in boot_cpu_data. This prevents an attacker with partial write support from affecting Xen's PTE generation logic by overriding the NX feature flag. The patch asserts support for the NX bit in PTEs at boot time and if so short-circuits the cpu_has_nx macro to 1. Alejandro Vallejo (3): tools: Add __AC() macro to common-macros.h x86/boot: Clear XD_DISABLE from the early boot path x86: Add Kconfig option to require NX bit support tools/include/xen-tools/common-macros.h | 3 ++ tools/libs/light/libxl_internal.h | 2 - tools/tests/x86_emulator/x86-emulate.h | 3 -- xen/arch/x86/Kconfig | 16 +++++++ xen/arch/x86/boot/head.S | 62 ++++++++++++++++++++++--- xen/arch/x86/boot/trampoline.S | 3 +- xen/arch/x86/cpu/intel.c | 16 +++---- xen/arch/x86/efi/efi-boot.h | 9 ++++ xen/arch/x86/include/asm/cpufeature.h | 3 +- xen/arch/x86/include/asm/msr-index.h | 2 +- xen/arch/x86/include/asm/x86-vendors.h | 6 +-- 11 files changed, 98 insertions(+), 27 deletions(-) -- 2.34.1
