Messages in this thread | | | From | <> | Subject | [PATCH v4 0/1] arm64/cpufeature: Support optionally disable MTE | Date | Tue, 3 Aug 2021 15:08:21 +0800 |
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From: Yee Lee <yee.lee@mediatek.com>
An option in runtime to disable MTE support is necessary for some scenarios such as HW issue workaround, FW tests and some evaluation works in performance and resoruce costs.
This patch supoorts to override id-reg on the shadow capability via comandline and suppress MTE feature.
SCTLR_EL1.ATA/ATA0 setting is moved to cpu_enable_mte() since they are not allowed to be cache TLB.
All works in this patch turn off related software support, but not fully disable MTE in HW side.
=== Test === QEMU5.2 + MTE
(1) normal boot MTE feature is enabled and HW-tags KASAN works.
(2) passed "arm64.nomte" in cmdline boot log: ..(skip) [ 0.000000] CPU features: SYS_ID_AA64PFR1_EL1[11:8]: forced to 0
==== Changed since v4: - Move ATA/ATA0 setting to cpu_enable_mte()
Changed since v3: - Add documentation text
Changed since v2: - Use id-reg override machanism to suppress feature.
Yee Lee (1): arm64/cpufeature: Optionally disable MTE via command-line
Documentation/admin-guide/kernel-parameters.txt | 3 +++ arch/arm64/include/asm/sysreg.h | 3 +-- arch/arm64/kernel/cpufeature.c | 3 +++ arch/arm64/kernel/idreg-override.c | 2 ++ 4 files changed, 9 insertions(+), 2 deletions(-)
-- 2.18.0
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