2021-07-29 02:09:06

by Yee Lee (李建誼)

Subject: [PATCH v2 0/1] Add option to disable mte support

From: Yee Lee <[email protected]>

For some case of low-end devices with limited resources,
an option to disable mte support is necessary.

This patch Adds an alias in id-reg override mechanism
to suppress the mte feature via passing a param.

=== Test ===
QEMU5.2 + mte
passed "arm64.nomte" in cmdline
boot log:
..(skip)
[ 0.000000] CPU features: SYS_ID_AA64PFR1_EL1[11:8]: forced to 0

Changed since v2:
- Use id-reg override machanism to suppress feature.

Yee Lee (1):
arm64/cpufeature: Add arm64.nomte to override id-reg

arch/arm64/kernel/idreg-override.c | 2 ++
1 file changed, 2 insertions(+)

--
2.18.0

2021-07-29 02:11:30

by Yee Lee (李建誼)

Subject: [PATCH v2 1/1] arm64/cpufeature: Add arm64.nomte to override id-reg

From: Yee Lee <[email protected]>

Add an alias, "arm64.nomte", to override id-reg and
suppress mte feature.

Suggested-by: Marc Zyngier <[email protected]>
Suggested-by: Suzuki K Poulose <[email protected]>
Signed-off-by: Yee Lee <[email protected]>
---
arch/arm64/kernel/idreg-override.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/arm64/kernel/idreg-override.c b/arch/arm64/kernel/idreg-override.c
index 53a381a7f65d..d8e606fe3c21 100644
--- a/arch/arm64/kernel/idreg-override.c
+++ b/arch/arm64/kernel/idreg-override.c
@@ -54,6 +54,7 @@ static const struct ftr_set_desc pfr1 __initconst = {
.override = &id_aa64pfr1_override,
.fields = {
{ "bt", ID_AA64PFR1_BT_SHIFT },
+ { "mte", ID_AA64PFR1_MTE_SHIFT},
{}
},
};
@@ -100,6 +101,7 @@ static const struct {
{ "arm64.nopauth",
"id_aa64isar1.gpi=0 id_aa64isar1.gpa=0 "
"id_aa64isar1.api=0 id_aa64isar1.apa=0" },
+ { "arm64.nomte", "id_aa64pfr1.mte=0" },
{ "nokaslr", "kaslr.disabled=1" },
};

--
2.18.0