Re: [PATCH 03/11] KVM: arm64: CCA: Check for RMI support at KVM init
From: Suzuki K Poulose
Date: Wed Nov 04 2026 - 05:39:41 EST
Hi Kohei
On 04/11/2026 10:27, Kohei Enju wrote:
On 11/04 19:23, Kohei Enju wrote:
Hi Steven,
On 11/02 14:12, Steven Price wrote:
Check if the RMI support is sufficient for using in KVM. Specifically, we
will only support creating realm VMs when KVM is set to 'rmm' mode.
Signed-off-by: Steven Price <steven.price@xxxxxxx>
---
arch/arm64/kvm/Kconfig | 1 +
arch/arm64/kvm/rmi.c | 4 +++-
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index cecea0820e52..d067063a3686 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -34,6 +34,7 @@ menuconfig KVM
select GUEST_PERF_EVENTS if PERF_EVENTS
select KVM_GUEST_MEMFD
select KVM_GENERIC_PRE_FAULT_MEMORY
+ select ARM_RMM_RMI
help
Support hosting virtualized guest machines.
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index 5ecc8b349869..9d118768550d 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -3,6 +3,7 @@
* Copyright (C) 2023-2026 ARM Ltd.
*/
+#include <linux/arm-rmi-cmds.h>
#include <linux/kvm_host.h>
#include <asm/virt.h>
@@ -12,7 +13,8 @@ void kvm_init_rmi(void)
if (kvm_get_mode() != KVM_MODE_RMM)
return;
- /* TODO: Check if the RMI is available */
+ if (!is_rmi_available())
+ return;
From an admin/operator's perspective, kvm_rmi_is_available would
silently remain FALSE in either of the following cases:
- kvm-arm.mode=rmm is set, but RMI is not available for some reason.
We could add a kvm_info() message for this.
- RMI is available, but the admin forgot to set kvm-arm.mode=rmm.
But not this one. We are additionally planning to move the RMM
activation to gate on kvm-arm.mode=rmm. I will send out a patch
soon.
Cheers
Suzuki