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Thu, 5 Feb 2026 17:47:43 +0000 Date: Thu, 5 Feb 2026 09:47:41 -0800 From: "Luck, Tony" To: Sohil Mehta CC: , Dave Hansen , "Thomas Gleixner" , Ingo Molnar , "Borislav Petkov" , Ard Biesheuvel , "H . Peter Anvin" , Andy Lutomirski , Peter Zijlstra , "Kirill A . 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This series > extends LASS support to EFI-enabled configurations. I tried these patches on a LASS-capable system with a kernel built with CONFIG_X86_VSYSCALL_EMULATION disabled, and traces added to efi_disable_lass() and efi_enable_lass(). System boots OK (with a bunch of my trace messages showing that CR4.LASS was disabled/enabled around EFI calls from several CPUs). Just for grins I commented out the CR4 changes from the efi_disable_lass() and efi_enable_lass(). System still boots OK, so it seems the EFI runtime calls during boot don't have any of the BIOS bugs that require LASS disable. Tested-by: Tony Luck -Tony