Re: [PATCH v15 17/37] KVM: arm64: Expose support for private memory

[Suzuki K Poulose <suzuki.poulose@arm.com>]

On 15/07/2026 15:28, Steven Price wrote:
> Select KVM_GENERIC_MEMORY_ATTRIBUTES and provide the necessary support
> functions.
> 
> Signed-off-by: Steven Price <steven.price@arm.com>
> ---

minor nit:

Changes since v14:
   * Switch to guest_memfd in-place memory conversion and drop support
     for KVM_VM_MEMORY_ATTRIBUTES.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>

> Changes since v13:
>   * Also update documentation to show that KVM_CAP_MEMORY_ATTRIBUTES is
>     used on arm64.
> Changes since v12:
>   * Only define kvm_arch_has_private_mem() when
>     CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES is set to avoid build issues
>     when KVM is disabled.
> Changes since v10:
>   * KVM_GENERIC_PRIVATE_MEM replacd with KVM_GENERIC_MEMORY_ATTRIBUTES.
> Changes since v9:
>   * Drop the #ifdef CONFIG_KVM_PRIVATE_MEM guard from the definition of
>     kvm_arch_has_private_mem()
> Changes since v2:
>   * Switch kvm_arch_has_private_mem() to a macro to avoid overhead of a
>     function call.
>   * Guard definitions of kvm_arch_{pre,post}_set_memory_attributes() with
>     #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES.
>   * Early out in kvm_arch_post_set_memory_attributes() if the WARN_ON
>     should trigger.
> ---
>   arch/arm64/include/asm/kvm_host.h | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index 9b46b39ed11e..993ead6e6449 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -1509,6 +1509,8 @@ 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)
> +
>   int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature);
>   bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu);
>