Re: [PATCH v4 08/21] KVM: arm64: Support SDEI_EVENT_STATUS hypercall

Eric Auger
2021-11-09T17:12:51Z

On 8/15/21 2:13 AM, Gavin Shan wrote:
> This supports SDEI_EVENT_STATUS hypercall. It's used by the guest
> to retrieve a bitmap to indicate the SDEI event states, including
> registration, enablement and delivery state.
>
> Signed-off-by: Gavin Shan <gshan@redhat.com>
> ---
> arch/arm64/kvm/sdei.c | 50 +++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 50 insertions(+)
>
> diff --git a/arch/arm64/kvm/sdei.c b/arch/arm64/kvm/sdei.c
> index a3ba69dc91cb..b95b8c4455e1 100644
> --- a/arch/arm64/kvm/sdei.c
> +++ b/arch/arm64/kvm/sdei.c
> @@ -367,6 +367,54 @@ static unsigned long kvm_sdei_hypercall_unregister(struct kvm_vcpu *vcpu)
> return ret;
> }
>
> +static unsigned long kvm_sdei_hypercall_status(struct kvm_vcpu *vcpu)
> +{
> + struct kvm *kvm = vcpu->kvm;
> + struct kvm_sdei_kvm *ksdei = kvm->arch.sdei;
> + struct kvm_sdei_vcpu *vsdei = vcpu->arch.sdei;
> + struct kvm_sdei_event *kse = NULL;
> + struct kvm_sdei_kvm_event *kske = NULL;
> + unsigned long event_num = smccc_get_arg1(vcpu);
> + int index = 0;
> + unsigned long ret = SDEI_SUCCESS;
> +
> + /* Sanity check */
> + if (!(ksdei && vsdei)) {
> + ret = SDEI_NOT_SUPPORTED;
> + goto out;
> + }
> +
> + if (!kvm_sdei_is_valid_event_num(event_num)) {
> + ret = SDEI_INVALID_PARAMETERS;
> + goto out;
> + }
if we were to support bound events, I do not know if a given even num
can disapper inbetween that check and the rest of the code, in which
case a lock would be needed?
> +
> + /*
> + * Check if the KVM event exists. None of the flags
> + * will be set if it doesn't exist.
> + */
> + spin_lock(&ksdei->lock);
> + kske = kvm_sdei_find_kvm_event(kvm, event_num);
> + if (!kske) {
> + ret = 0;
> + goto unlock;
> + }
> +
> + index = (kse->state.type == SDEI_EVENT_TYPE_PRIVATE) ?
> + vcpu->vcpu_idx : 0;
> + if (kvm_sdei_is_registered(kske, index))
> + ret |= (1UL << SDEI_EVENT_STATUS_REGISTERED);
> + if (kvm_sdei_is_enabled(kske, index))
> + ret |= (1UL << SDEI_EVENT_STATUS_ENABLED);
> + if (kske->state.refcount)
> + ret |= (1UL << SDEI_EVENT_STATUS_RUNNING);
> +
> +unlock:
> + spin_unlock(&ksdei->lock);
> +out:
> + return ret;
> +}
> +
> int kvm_sdei_hypercall(struct kvm_vcpu *vcpu)
> {
> u32 func = smccc_get_function(vcpu);
> @@ -395,6 +443,8 @@ int kvm_sdei_hypercall(struct kvm_vcpu *vcpu)
> ret = kvm_sdei_hypercall_unregister(vcpu);
> break;
> case SDEI_1_0_FN_SDEI_EVENT_STATUS:
> + ret = kvm_sdei_hypercall_status(vcpu);
> + break;
> case SDEI_1_0_FN_SDEI_EVENT_GET_INFO:
> case SDEI_1_0_FN_SDEI_EVENT_ROUTING_SET:
> case SDEI_1_0_FN_SDEI_PE_MASK:
>
Thanks

Eric