Re: [PATCH v16 24/45] KVM: arm64: Expose support for private memory

On 05/08/2026 17:02, Ackerley Tng wrote:
> Steven Price <[email protected]> writes:
> 
>> Select KVM_GENERIC_MEMORY_ATTRIBUTES and provide the necessary support
>> functions.
>>
>> Reviewed-by: Suzuki K Poulose <[email protected]>
>> Signed-off-by: Steven Price <[email protected]>
>> ---
>> Changes since v14:
>>   * Switch to guest_memfd in-place memory conversion and drop support
>>     for KVM_VM_MEMORY_ATTRIBUTES.
>>
>> [...snip...]
>>
>> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
>> index 15d42d1993bb..146c52f867c0 100644
>> --- a/arch/arm64/include/asm/kvm_host.h
>> +++ b/arch/arm64/include/asm/kvm_host.h
>> @@ -1510,6 +1510,8 @@ struct kvm *kvm_arch_alloc_vm(void);
>>
>>   #define vcpu_is_protected(vcpu)		kvm_vm_is_protected((vcpu)->kvm)
>>
>> +#define kvm_arch_has_private_mem(kvm) ((kvm)->arch.is_realm)
>> +
> 
> Perhaps related to Fuad's question about pKVM and CCA state: would
> conditioning this on is_realm mess up pKVM?

Not really. The comment is about unifiying the conditions which
both pKVM and Realm selects. Right now, only CCA uses guest_memfd.
When pkvm comes along to use guest_memfd, this could be something
like:

kvm->arch.needs_private_mem  (set by both pKVM and Realm) ?

Cheers
Suzuki


> 
>>   int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature);
>>   bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu);
>>
>> --
>> 2.43.0