[PATCH v1 1/4] KVM: arm64: Allow early calls to pKVM host_share/unshare_hyp

[Fuad Tabba]

On Fri, 12 Jun 2026 at 15:22, Vincent Donnefort <vdonnefort at google.com> wrote:
>
> The hypervisor tracing for pKVM relies on the __pkvm_host_share_hyp and
> __pkvm_host_unshare_hyp HVCs. In order to start tracing as early as
> possible, allow those two HVCs before the host is deprivileged.
>
> Signed-off-by: Vincent Donnefort <vdonnefort at google.com>

To my good friend Sashiko:
https://lore.kernel.org/all/20260529121755.2923500-1-tabba@google.com/

The hyp_trace_load() issue seems legit though.

As for this patch itself:

Reviewed-by: Fuad Tabba <tabba at google.com>
Tested-by: Fuad Tabba <tabba at google.com>

Cheers,
/fuad


>
> diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
> index 043495f7fc78..fb049c40d04f 100644
> --- a/arch/arm64/include/asm/kvm_asm.h
> +++ b/arch/arm64/include/asm/kvm_asm.h
> @@ -89,12 +89,12 @@ enum __kvm_host_smccc_func {
>         __KVM_HOST_SMCCC_FUNC___vgic_v3_restore_vmcr_aprs,
>         __KVM_HOST_SMCCC_FUNC___vgic_v5_save_apr,
>         __KVM_HOST_SMCCC_FUNC___vgic_v5_restore_vmcr_apr,
> +       __KVM_HOST_SMCCC_FUNC___pkvm_host_share_hyp,
> +       __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_hyp,
>
>         MARKER(__KVM_HOST_SMCCC_FUNC_PKVM_ONLY),
>
>         /* Hypercalls that are available only when pKVM has finalised. */
> -       __KVM_HOST_SMCCC_FUNC___pkvm_host_share_hyp,
> -       __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_hyp,
>         __KVM_HOST_SMCCC_FUNC___pkvm_host_donate_guest,
>         __KVM_HOST_SMCCC_FUNC___pkvm_host_share_guest,
>         __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_guest,
> diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
> index 06db299c37a8..f0c52667cf52 100644
> --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
> +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
> @@ -721,9 +721,9 @@ static const hcall_t host_hcall[] = {
>         HANDLE_FUNC(__vgic_v3_restore_vmcr_aprs),
>         HANDLE_FUNC(__vgic_v5_save_apr),
>         HANDLE_FUNC(__vgic_v5_restore_vmcr_apr),
> -
>         HANDLE_FUNC(__pkvm_host_share_hyp),
>         HANDLE_FUNC(__pkvm_host_unshare_hyp),
> +
>         HANDLE_FUNC(__pkvm_host_donate_guest),
>         HANDLE_FUNC(__pkvm_host_share_guest),
>         HANDLE_FUNC(__pkvm_host_unshare_guest),
> --
> 2.54.0.1136.gdb2ca164c4-goog
>