From: Ben Horgan <ben.horgan@arm.com>
Date: Fri, 13 Mar 2026 14:45:42 +0000 (+0000)
Subject: KVM: arm64: Make MPAMSM_EL1 accesses UNDEF
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2e7c684bdb50cfaf98da80ebaab4a961fdcd1aa2;p=thirdparty%2Flinux.git

KVM: arm64: Make MPAMSM_EL1 accesses UNDEF

The MPAMSM_EL1 register controls the MPAM labeling for an SMCU, Streaming
Mode Compute Unit. As there is no MPAM support in KVM, make sure MPAMSM_EL1
accesses trigger an UNDEF.

Tested-by: Gavin Shan <gshan@redhat.com>
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Zeng Heng <zengheng4@huawei.com>
Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com>
Tested-by: Jesse Chick <jessechick@os.amperecomputing.com>
Reviewed-by: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Ben Horgan <ben.horgan@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
---

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 1b4cacb6e918a..0edd655934a97 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -3376,6 +3376,8 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 
 	{ SYS_DESC(SYS_MPAM1_EL1), undef_access },
 	{ SYS_DESC(SYS_MPAM0_EL1), undef_access },
+	{ SYS_DESC(SYS_MPAMSM_EL1), undef_access },
+
 	{ SYS_DESC(SYS_VBAR_EL1), access_rw, reset_val, VBAR_EL1, 0 },
 	{ SYS_DESC(SYS_DISR_EL1), NULL, reset_val, DISR_EL1, 0 },