[PATCH v17 06/20] KVM: arm64: CCA: Add a new mode for supporting Realm guests

Gavin Shan gshan at redhat.com
Thu Sep 10 02:40:13 PDT 2026


On 9/10/26 6:43 PM, Suzuki K Poulose wrote:
> On 10/09/2026 06:53, Gavin Shan wrote:
>> Hi Suzuki,
>>
>> On 9/9/26 2:22 AM, Suzuki K Poulose wrote:
>>> Add an explicit mode to support Arm CCA guests.
>>>
>>> Signed-off-by: Suzuki K Poulose <suzuki.poulose at 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)
>>>
>>
>> I'm not sure, but 'realm' would be more appropriate name. rmm (Real Management Monitor) is
>> the term limited to the firmware to me. Besides, we have been using 'realm' broadly in this
>> series like kvm_vm_is_realm(), kvm_realm_state() and so on.
> 
> May be. But we use the "mode" of the hypervisor in question here, mostly. e.g., nvhe, vhe, protected etc. So, I went with RMM (in favor
> of CCA). Does that make sense ? Also, we rely on firmware/arm_rmm for
> the support. So, it kind of make sense to keep it "rmm" ?
> 

Ok, lets keep 'rmm' unless somebody else has better suggestion.

> Cheers
> Suzuki
> 

Thanks,
Gavin




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