Re: [PATCH v4 18/21] KVM: arm64: Support SDEI event injection

Eric Auger
2021-11-10T14:05:50Z

On 8/15/21 2:13 AM, Gavin Shan wrote:
> This supports SDEI event injection by implementing kvm_sdei_inject().
> It's called by kernel directly or VMM through ioctl command to inject
> SDEI event to the specific vCPU.
>
> Signed-off-by: Gavin Shan <gshan@redhat.com>
> ---
> arch/arm64/include/asm/kvm_sdei.h | 2 +
> arch/arm64/include/uapi/asm/kvm_sdei.h | 1 +
> arch/arm64/kvm/sdei.c | 108 +++++++++++++++++++++++++
> 3 files changed, 111 insertions(+)
>
> diff --git a/arch/arm64/include/asm/kvm_sdei.h b/arch/arm64/include/asm/kvm_sdei.h
> index a997989bab77..51087fe971ba 100644
> --- a/arch/arm64/include/asm/kvm_sdei.h
> +++ b/arch/arm64/include/asm/kvm_sdei.h
> @@ -124,6 +124,8 @@ void kvm_sdei_create_vcpu(struct kvm_vcpu *vcpu);
> int kvm_sdei_hypercall(struct kvm_vcpu *vcpu);
> int kvm_sdei_register_notifier(struct kvm *kvm, unsigned long num,
> kvm_sdei_notifier notifier);
> +int kvm_sdei_inject(struct kvm_vcpu *vcpu,
> + unsigned long num, bool immediate);
> void kvm_sdei_deliver(struct kvm_vcpu *vcpu);
> long kvm_sdei_vm_ioctl(struct kvm *kvm, unsigned long arg);
> long kvm_sdei_vcpu_ioctl(struct kvm_vcpu *vcpu, unsigned long arg);
> diff --git a/arch/arm64/include/uapi/asm/kvm_sdei.h b/arch/arm64/include/uapi/asm/kvm_sdei.h
> index b916c3435646..f7a6b2b22b50 100644
> --- a/arch/arm64/include/uapi/asm/kvm_sdei.h
> +++ b/arch/arm64/include/uapi/asm/kvm_sdei.h
> @@ -67,6 +67,7 @@ struct kvm_sdei_vcpu_state {
> #define KVM_SDEI_CMD_SET_VEVENT 7
> #define KVM_SDEI_CMD_GET_VCPU_STATE 8
> #define KVM_SDEI_CMD_SET_VCPU_STATE 9
> +#define KVM_SDEI_CMD_INJECT_EVENT 10
>
> struct kvm_sdei_cmd {
> __u32 cmd;
> diff --git a/arch/arm64/kvm/sdei.c b/arch/arm64/kvm/sdei.c
> index 79315b77f24b..7c2789cd1421 100644
> --- a/arch/arm64/kvm/sdei.c
> +++ b/arch/arm64/kvm/sdei.c
> @@ -802,6 +802,111 @@ int kvm_sdei_register_notifier(struct kvm *kvm,
> return ret;
> }
>
> +int kvm_sdei_inject(struct kvm_vcpu *vcpu,
> + unsigned long num,
> + bool immediate)
don't get the immediate param.
> +{
> + 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;
> + struct kvm_sdei_vcpu_event *ksve = NULL;
> + int index, ret = 0;
> +
> + /* Sanity check */
> + if (!(ksdei && vsdei)) {
> + ret = -EPERM;
> + goto out;
> + }
> +
> + if (!kvm_sdei_is_valid_event_num(num)) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + /* Check the kvm event */
> + spin_lock(&ksdei->lock);
> + kske = kvm_sdei_find_kvm_event(kvm, num);
> + if (!kske) {
> + ret = -ENOENT;
> + goto unlock_kvm;
> + }
> +
> + kse = kske->kse;
> + index = (kse->state.type == SDEI_EVENT_TYPE_PRIVATE) ?
> + vcpu->vcpu_idx : 0;
> + if (!(kvm_sdei_is_registered(kske, index) &&
> + kvm_sdei_is_enabled(kske, index))) {
> + ret = -EPERM;
> + goto unlock_kvm;
> + }
> +
> + /* Check the vcpu state */
> + spin_lock(&vsdei->lock);
> + if (vsdei->state.masked) {
> + ret = -EPERM;
> + goto unlock_vcpu;
> + }
> +
> + /* Check if the event can be delivered immediately */
> + if (immediate) {
According to the dispatcher pseudo code this should be always checked?
> + if (kse->state.priority == SDEI_EVENT_PRIORITY_CRITICAL &&
> + !list_empty(&vsdei->critical_events)) {
> + ret = -ENOSPC;
> + goto unlock_vcpu;
> + }
> +
> + if (kse->state.priority == SDEI_EVENT_PRIORITY_NORMAL &&
> + (!list_empty(&vsdei->critical_events) ||
> + !list_empty(&vsdei->normal_events))) {
> + ret = -ENOSPC;
> + goto unlock_vcpu;
> + }
> + }
What about shared event dispatching. I don't see the afficinity checked
anywhere?
> +
> + /* Check if the vcpu event exists */
> + ksve = kvm_sdei_find_vcpu_event(vcpu, num);
> + if (ksve) {
> + kske->state.refcount++;
> + ksve->state.refcount++;
why this double refcount increment??
> + kvm_make_request(KVM_REQ_SDEI, vcpu);
> + goto unlock_vcpu;
> + }
> +
> + /* Allocate vcpu event */
> + ksve = kzalloc(sizeof(*ksve), GFP_KERNEL);
> + if (!ksve) {
> + ret = -ENOMEM;
> + goto unlock_vcpu;
> + }
> +
> + /*
> + * We should take lock to update KVM event state because its
> + * reference count might be zero. In that case, the KVM event
> + * could be destroyed.
> + */
> + kske->state.refcount++;
> + ksve->state.num = num;
> + ksve->state.refcount = 1;
> + ksve->kske = kske;
> + ksve->vcpu = vcpu;
> +
> + if (kse->state.priority == SDEI_EVENT_PRIORITY_CRITICAL)
> + list_add_tail(&ksve->link, &vsdei->critical_events);
> + else
> + list_add_tail(&ksve->link, &vsdei->normal_events);
> +
> + kvm_make_request(KVM_REQ_SDEI, vcpu);
> +
> +unlock_vcpu:
> + spin_unlock(&vsdei->lock);
> +unlock_kvm:
> + spin_unlock(&ksdei->lock);
> +out:
> + return ret;
> +}
> +
> void kvm_sdei_deliver(struct kvm_vcpu *vcpu)
> {
> struct kvm *kvm = vcpu->kvm;
> @@ -1317,6 +1422,9 @@ long kvm_sdei_vcpu_ioctl(struct kvm_vcpu *vcpu, unsigned long arg)
> case KVM_SDEI_CMD_SET_VCPU_STATE:
> ret = kvm_sdei_set_vcpu_state(vcpu, &cmd->ksv_state);
> break;
> + case KVM_SDEI_CMD_INJECT_EVENT:
> + ret = kvm_sdei_inject(vcpu, cmd->num, false);
> + break;
> default:
> ret = -EINVAL;
> }
>
Eric