Hi Gavin,
On 1/12/22 3:54 AM, Gavin Shan wrote:
> Hi Eric,
>
> On 11/10/21 2:47 AM, Eric Auger wrote:
>> On 8/15/21 2:13 AM, Gavin Shan wrote:
>>> This supports SDEI_EVENT_ROUTING_SET hypercall. It's used by the
>>> guest to set route mode and affinity for the registered KVM event.
>>> It's only valid for the shared events. It's not allowed to do so
>>> when the corresponding event has been raised to the guest.
>>>
>>> Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx>
>>> ---
>>> arch/arm64/kvm/sdei.c | 64 +++++++++++++++++++++++++++++++++++++++++++
>>> 1 file changed, 64 insertions(+)
>>>
>>> diff --git a/arch/arm64/kvm/sdei.c b/arch/arm64/kvm/sdei.c
>>> index 5dfa74b093f1..458695c2394f 100644
>>> --- a/arch/arm64/kvm/sdei.c
>>> +++ b/arch/arm64/kvm/sdei.c
>>> @@ -489,6 +489,68 @@ static unsigned long
>>> kvm_sdei_hypercall_info(struct kvm_vcpu *vcpu)
>>> return ret;
>>> }
>>> +static unsigned long kvm_sdei_hypercall_route(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);
>>> + unsigned long route_mode = smccc_get_arg2(vcpu);
>>> + unsigned long route_affinity = smccc_get_arg3(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 (!(route_mode == SDEI_EVENT_REGISTER_RM_ANY ||
>>> + route_mode == SDEI_EVENT_REGISTER_RM_PE)) {
>>> + ret = SDEI_INVALID_PARAMETERS;
>>> + goto out;
>>> + }
>> Some sanity checking on the affinity arg could be made as well according
>> to 5.1.2 affinity desc. The fn shall return INVALID_PARAMETER in case
>> of invalid affinity.
>
> Yep, you're right. I didn't figure out it. I may put a comment here.
> For now, the SDEI client driver in the guest kernel doesn't attempt
> to change the routing mode.
>
> /* FIXME: The affinity should be verified */
>
>>> +
>>> + /* Check if the KVM event has been registered */
>>> + spin_lock(&ksdei->lock);
>>> + kske = kvm_sdei_find_kvm_event(kvm, event_num);
>>> + if (!kske) {
>>> + ret = SDEI_INVALID_PARAMETERS;
>>> + goto unlock;
>>> + }
>>> +
>>> + /* Validate KVM event state */
>>> + kse = kske->kse;
>>> + if (kse->state.type != SDEI_EVENT_TYPE_SHARED) {
>>> + ret = SDEI_INVALID_PARAMETERS;
>>> + goto unlock;
>>> + }
>>> +
>> Event handler is in a state other than: handler-registered.
>
> They're equivalent as the handler is provided as a parameter when
> the event is registered.
>
>>> + if (!kvm_sdei_is_registered(kske, index) ||
>>> + kvm_sdei_is_enabled(kske, index) ||
>>> + kske->state.refcount) {
>> I am not sure about the refcount role here. Does it make sure the state
>> is != handler-enabled and running or handler-unregister-pending?
>>
>> I think we would gain in readibility if we had a helper to check whether
>> we are in those states?
>
> @refcount here indicates pending SDEI event for delivery. In this case,
> chaning its routing mode is disallowed.
OK. I guess you will document the refcount role somewhere.
Thanks
Eric
>
>>> + ret = SDEI_DENIED;
>>> + goto unlock;
>>> + }
>>> +
>>> + /* Update state */
>>> + kske->state.route_mode = route_mode;
>>> + kske->state.route_affinity = route_affinity;
>>> +
>>> +unlock:
>>> + spin_unlock(&ksdei->lock);
>>> +out:
>>> + return ret;
>>> +}
>>> +
>>> int kvm_sdei_hypercall(struct kvm_vcpu *vcpu)
>>> {
>>> u32 func = smccc_get_function(vcpu);
>>> @@ -523,6 +585,8 @@ int kvm_sdei_hypercall(struct kvm_vcpu *vcpu)
>>> ret = kvm_sdei_hypercall_info(vcpu);
>>> break;
>>> case SDEI_1_0_FN_SDEI_EVENT_ROUTING_SET:
>>> + ret = kvm_sdei_hypercall_route(vcpu);
>>> + break;
>>> case SDEI_1_0_FN_SDEI_PE_MASK:
>>> case SDEI_1_0_FN_SDEI_PE_UNMASK:
>>> case SDEI_1_0_FN_SDEI_INTERRUPT_BIND:
>>>
>
> Thanks,
> Gavin
>
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