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| author | Pawan Gupta <pawan.kumar.gupta@linux.intel.com> | 2024-11-18 09:53:12 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-05-18 08:21:26 +0200 |
| commit | 139c0b8318c2ea8afd2f12b6401466c6010286da (patch) | |
| tree | 9e035ba3e8a79e3e1be625b8dbd02bcfa326912d /Documentation/admin-guide | |
| parent | b1701fee52d1d68d1e12ad140b3551435a8e9fe7 (diff) | |
| download | linux-139c0b8318c2ea8afd2f12b6401466c6010286da.tar.gz linux-139c0b8318c2ea8afd2f12b6401466c6010286da.tar.bz2 linux-139c0b8318c2ea8afd2f12b6401466c6010286da.zip | |
x86/its: Add "vmexit" option to skip mitigation on some CPUs
commit 2665281a07e19550944e8354a2024635a7b2714a upstream.
Ice Lake generation CPUs are not affected by guest/host isolation part of
ITS. If a user is only concerned about KVM guests, they can now choose a
new cmdline option "vmexit" that will not deploy the ITS mitigation when
CPU is not affected by guest/host isolation. This saves the performance
overhead of ITS mitigation on Ice Lake gen CPUs.
When "vmexit" option selected, if the CPU is affected by ITS guest/host
isolation, the default ITS mitigation is deployed.
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 6384244080d4..6938c8cd7a6f 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2033,6 +2033,8 @@ off: Disable mitigation. force: Force the ITS bug and deploy default mitigation. + vmexit: Only deploy mitigation if CPU is affected by + guest/host isolation part of ITS. For details see: Documentation/admin-guide/hw-vuln/indirect-target-selection.rst |