[PATCH v14 26/44] arm64: RMI: Allow populating initial contents

[Suzuki K Poulose]

On 08/06/2026 10:36, Steven Price wrote:
> On 28/05/2026 06:30, Gavin Shan wrote:
>> Hi Steve,
>>
>> On 5/13/26 11:17 PM, Steven Price wrote:
>>> The VMM needs to populate the realm with some data before starting (e.g.
>>> a kernel and initrd). This is measured by the RMM and used as part of
>>> the attestation later on.
>>>
>>> Signed-off-by: Steven Price <steven.price at arm.com>

...

>>> diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
>>> index a89873a5eb77..209087bcf399 100644
>>> --- a/arch/arm64/kvm/rmi.c
>>> +++ b/arch/arm64/kvm/rmi.c
>>> @@ -486,6 +486,75 @@ void kvm_realm_unmap_range(struct kvm *kvm,
>>> unsigned long start,
>>>            realm_unmap_private_range(kvm, start, end, may_block);
>>>    }
>>>    +static int realm_data_map_init(struct kvm *kvm, unsigned long ipa,
>>> +                   kvm_pfn_t dst_pfn, kvm_pfn_t src_pfn,
>>> +                   unsigned long flags)
>>> +{
>>> +    struct realm *realm = &kvm->arch.realm;
>>> +    phys_addr_t rd = virt_to_phys(realm->rd);
>>> +    phys_addr_t dst_phys, src_phys;
>>> +    int ret;
>>> +
>>> +    dst_phys = __pfn_to_phys(dst_pfn);
>>> +    src_phys = __pfn_to_phys(src_pfn);
>>> +
>>> +    if (rmi_delegate_page(dst_phys))
>>> +        return -ENXIO;
>>> +
>>> +    ret = rmi_rtt_data_map_init(rd, dst_phys, ipa, src_phys, flags);
>>> +    if (RMI_RETURN_STATUS(ret) == RMI_ERROR_RTT) {
>>> +        /* Create missing RTTs and retry */
>>> +        int level = RMI_RETURN_INDEX(ret);
>>> +
>>> +        KVM_BUG_ON(level == KVM_PGTABLE_LAST_LEVEL, kvm);
>>
>>          KVM_BUG_ON(level >= KVM_PGTABLE_LAST_LEVEL, kvm);
> 
> Ack.
> 

Thinking more about this, I guess a buggy VMM can trigger this
by populating twice ? (level == KVM_PGTABLE_LAST_LEVEL). So, we should
return the error back, than warning here and suppressing the error ?


Suzuki