[PATCH v18 14/23] KVM: arm64: CCA: Add a new mode for supporting Realm guests
From: Suzuki K Poulose <suzuki.poulose@arm.com>
Date: 2026-09-15 16:02:35
Also in:
kvm, kvmarm, linux-arm-kernel, lkml
Subsystem:
arm64 port (aarch64 architecture), documentation, kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Jonathan Corbet, Marc Zyngier, Oliver Upton, Linus Torvalds
Add an explicit mode to support Arm CCA guests. Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> --- Documentation/admin-guide/kernel-parameters.txt | 3 +++ arch/arm64/include/asm/kvm_host.h | 1 + arch/arm64/kvm/arm.c | 5 +++++ 3 files changed, 9 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 68647ff4bdd24..1afe3df3b923e 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt@@ -3256,6 +3256,9 @@ Kernel parameters nested: VHE-based mode with support for nested virtualization. Requires at least ARMv8.4 hardware (with FEAT_NV2). + rmm: Support for running confidential guests in Realm + world using RMM, as defined by Arm Confidential + Compute Architecture (CCA) Defaults to VHE/nVHE based on hardware support. Setting mode to "protected" will disable kexec and hibernation
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 09910b2c61bfb..3cedb71f49ab8 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h@@ -69,6 +69,7 @@ enum kvm_mode { KVM_MODE_DEFAULT, KVM_MODE_PROTECTED, KVM_MODE_NV, + KVM_MODE_RMM, KVM_MODE_NONE, }; #ifdef CONFIG_KVM
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 42d9385f5e329..ae09d0d9812c5 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c@@ -3283,6 +3283,11 @@ static int __init early_kvm_mode_cfg(char *arg) return 0; } + if (strcmp(arg, "rmm") == 0 && !WARN_ON(!is_kernel_in_hyp_mode())) { + kvm_mode = KVM_MODE_RMM; + return 0; + } + return -EINVAL; } early_param("kvm-arm.mode", early_kvm_mode_cfg);
--
2.43.0