forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 17
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
x86/split_lock: Rework the initialization flow of split lock detection
Current initialization flow of split lock detection has following issues: 1. It assumes the initial value of MSR_TEST_CTRL.SPLIT_LOCK_DETECT to be zero. However, it's possible that BIOS/firmware has set it. 2. X86_FEATURE_SPLIT_LOCK_DETECT flag is unconditionally set even if there is a virtualization flaw that FMS indicates the existence while it's actually not supported. Rework the initialization flow to solve above issues. In detail, explicitly clear and set split_lock_detect bit to verify MSR_TEST_CTRL can be accessed, and rdmsr after wrmsr to ensure bit is cleared/set successfully. X86_FEATURE_SPLIT_LOCK_DETECT flag is set only when the feature does exist and the feature is not disabled with kernel param "split_lock_detect=off" On each processor, explicitly updating the SPLIT_LOCK_DETECT bit based on sld_sate in split_lock_init() since BIOS/firmware may touch it. Originally-by: Thomas Gleixner <[email protected]> Signed-off-by: Xiaoyao Li <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
- Loading branch information
Showing
1 changed file
with
42 additions
and
33 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters