On Mon, 27 Oct 2025 15:25:51 +0530
"Aneesh Kumar K.V (Arm)" <aneesh.kumar@kernel.org> wrote:
Hi Aneesh,
Great to see this support - this review might be a little superficial as
I think it's first time I've looked at this and I'll be getting my head around
it whilst reviewing.
Small process thing:
Always include a stand alone description in here. Some git clients
don't put the patch title near the commit text. Add something like
Export kvm_has_da_feature() for use in later patches.
> This will be used in later patches
Patch title made me think this was exporting something that already existed.
Probably better to say Add kvm_has_da_feature() helper for use in later patches
or something like that.
>
> Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
> ---
> arch/arm64/include/asm/kvm_rmi.h | 1 +
> arch/arm64/include/asm/rmi_smc.h | 1 +
> arch/arm64/kvm/rmi.c | 6 ++++++
> 3 files changed, 8 insertions(+)
>
> diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
> index 1b2cdaac6c50..a967061af6ed 100644
> --- a/arch/arm64/include/asm/kvm_rmi.h
> +++ b/arch/arm64/include/asm/kvm_rmi.h
> @@ -90,6 +90,7 @@ u32 kvm_realm_ipa_limit(void);
> u32 kvm_realm_vgic_nr_lr(void);
> u8 kvm_realm_max_pmu_counters(void);
> unsigned int kvm_realm_sve_max_vl(void);
> +bool kvm_has_da_feature(void);
>
> u64 kvm_realm_reset_id_aa64dfr0_el1(const struct kvm_vcpu *vcpu, u64 val);
>
> diff --git a/arch/arm64/include/asm/rmi_smc.h b/arch/arm64/include/asm/rmi_smc.h
> index 1000368f1bca..2ea657a87402 100644
> --- a/arch/arm64/include/asm/rmi_smc.h
> +++ b/arch/arm64/include/asm/rmi_smc.h
> @@ -87,6 +87,7 @@ enum rmi_ripas {
> #define RMI_FEATURE_REGISTER_0_GICV3_NUM_LRS GENMASK(37, 34)
> #define RMI_FEATURE_REGISTER_0_MAX_RECS_ORDER GENMASK(41, 38)
> #define RMI_FEATURE_REGISTER_0_Reserved GENMASK(63, 42)
> +#define RMI_FEATURE_REGISTER_0_DA BIT(42)
Guess you want to be updating Reserved as seems bit 42 isn't any more.
>
> #define RMI_REALM_PARAM_FLAG_LPA2 BIT(0)
> #define RMI_REALM_PARAM_FLAG_SVE BIT(1)
> diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
> index 478a73e0b35a..08f3d2362dfd 100644
> --- a/arch/arm64/kvm/rmi.c
> +++ b/arch/arm64/kvm/rmi.c
> @@ -1738,6 +1738,12 @@ int kvm_init_realm_vm(struct kvm *kvm)
> return 0;
> }
>
> +bool kvm_has_da_feature(void)
> +{
> + return rmi_has_feature(RMI_FEATURE_REGISTER_0_DA);
> +}
> +EXPORT_SYMBOL_GPL(kvm_has_da_feature);
> +
> void kvm_init_rmi(void)
> {
> /* Only 4k page size on the host is supported */