Re: [PATCH v7 22/45] KVM: arm64: Handle realm VCPU load

Gavin Shan
2025-03-04T05:15:53Z

On 2/14/25 2:14 AM, Steven Price wrote:
> When loading a realm VCPU much of the work is handled by the RMM so only
> some of the actions are required. Rearrange kvm_arch_vcpu_load()
> slightly so we can bail out early for a realm guest.
>
> Signed-off-by: Steven Price <steven.price@arm.com>
> ---
> arch/arm64/kvm/arm.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>

One nitpick below:

Reviewed-by: Gavin Shan <gshan@redhat.com>

> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index 49ad633c5ca5..3e13e3d87ed9 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -633,10 +633,6 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
> kvm_vgic_load(vcpu);
> kvm_timer_vcpu_load(vcpu);
> kvm_vcpu_load_debug(vcpu);
> - if (has_vhe())
> - kvm_vcpu_load_vhe(vcpu);
> - kvm_arch_vcpu_load_fp(vcpu);
> - kvm_vcpu_pmu_restore_guest(vcpu);
> if (kvm_arm_is_pvtime_enabled(&vcpu->arch))
> kvm_make_request(KVM_REQ_RECORD_STEAL, vcpu);
>
> @@ -659,6 +655,14 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
> kvm_call_hyp(__vgic_v3_restore_vmcr_aprs,
> &vcpu->arch.vgic_cpu.vgic_v3);
> }

A spare line is needed here.

> + /* No additional state needs to be loaded on Realmed VMs */
> + if (vcpu_is_rec(vcpu))
> + return;
> +
> + if (has_vhe())
> + kvm_vcpu_load_vhe(vcpu);
> + kvm_arch_vcpu_load_fp(vcpu);
> + kvm_vcpu_pmu_restore_guest(vcpu);
>
> if (!cpumask_test_cpu(cpu, vcpu->kvm->arch.supported_cpus))
> vcpu_set_on_unsupported_cpu(vcpu);

Thanks,
Gavin