On 8/15/21 2:13 AM, Gavin Shan wrote:
> This supports ioctl commands on VM to manage the various objects.
> It's primarily used by VMM to accomplish live migration. The ioctl
> commands introduced by this are highlighted as blow:
below
> 
>    * KVM_SDEI_CMD_GET_VERSION
>      Retrieve the version of current implementation
which implementation, SDEI?
>    * KVM_SDEI_CMD_SET_EVENT
>      Add event to be exported from KVM so that guest can register
>      against it afterwards
>    * KVM_SDEI_CMD_GET_KEVENT_COUNT
>      Retrieve number of registered SDEI events
>    * KVM_SDEI_CMD_GET_KEVENT
>      Retrieve the state of the registered SDEI event
>    * KVM_SDEI_CMD_SET_KEVENT
>      Populate the registered SDEI event
I think we really miss the full picture of what you want to achieve with
those IOCTLs or at least I fail to get it. Please document the UAPI
separately including the structs and IOCTLs.
> 
> Signed-off-by: Gavin Shan <[email protected]>
> ---
>  arch/arm64/include/asm/kvm_sdei.h      |   1 +
>  arch/arm64/include/uapi/asm/kvm_sdei.h |  17 +++
>  arch/arm64/kvm/arm.c                   |   3 +
>  arch/arm64/kvm/sdei.c                  | 171 +++++++++++++++++++++++++
>  include/uapi/linux/kvm.h               |   3 +
>  5 files changed, 195 insertions(+)
> 
> diff --git a/arch/arm64/include/asm/kvm_sdei.h 
> b/arch/arm64/include/asm/kvm_sdei.h
> index 19f2d9b91f85..8f5ea947ed0e 100644
> --- a/arch/arm64/include/asm/kvm_sdei.h
> +++ b/arch/arm64/include/asm/kvm_sdei.h
> @@ -125,6 +125,7 @@ int kvm_sdei_hypercall(struct kvm_vcpu *vcpu);
>  int kvm_sdei_register_notifier(struct kvm *kvm, unsigned long num,
>                              kvm_sdei_notifier notifier);
>  void kvm_sdei_deliver(struct kvm_vcpu *vcpu);
> +long kvm_sdei_vm_ioctl(struct kvm *kvm, unsigned long arg);
>  void kvm_sdei_destroy_vcpu(struct kvm_vcpu *vcpu);
>  void kvm_sdei_destroy_vm(struct kvm *kvm);
>  
> diff --git a/arch/arm64/include/uapi/asm/kvm_sdei.h 
> b/arch/arm64/include/uapi/asm/kvm_sdei.h
> index 4ef661d106fe..35ff05be3c28 100644
> --- a/arch/arm64/include/uapi/asm/kvm_sdei.h
> +++ b/arch/arm64/include/uapi/asm/kvm_sdei.h
> @@ -57,5 +57,22 @@ struct kvm_sdei_vcpu_state {
>       struct kvm_sdei_vcpu_regs       normal_regs;
>  };
>  
> +#define KVM_SDEI_CMD_GET_VERSION             0
> +#define KVM_SDEI_CMD_SET_EVENT                       1
> +#define KVM_SDEI_CMD_GET_KEVENT_COUNT                2
> +#define KVM_SDEI_CMD_GET_KEVENT                      3
> +#define KVM_SDEI_CMD_SET_KEVENT                      4
> +
> +struct kvm_sdei_cmd {
> +     __u32                                           cmd;
> +     union {
> +             __u32                                   version;
> +             __u32                                   count;
> +             __u64                                   num;
> +             struct kvm_sdei_event_state             kse_state;
> +             struct kvm_sdei_kvm_event_state         kske_state;
> +     };
> +};
> +
>  #endif /* !__ASSEMBLY__ */
>  #endif /* _UAPI__ASM_KVM_SDEI_H */
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index 0c3db1ef1ba9..8d61585124b2 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -1389,6 +1389,9 @@ long kvm_arch_vm_ioctl(struct file *filp,
>                       return -EFAULT;
>               return kvm_vm_ioctl_mte_copy_tags(kvm, &copy_tags);
>       }
> +     case KVM_ARM_SDEI_COMMAND: {
> +             return kvm_sdei_vm_ioctl(kvm, arg);
> +     }
>       default:
>               return -EINVAL;
>       }
> diff --git a/arch/arm64/kvm/sdei.c b/arch/arm64/kvm/sdei.c
> index 5f7a37dcaa77..bdd76c3e5153 100644
> --- a/arch/arm64/kvm/sdei.c
> +++ b/arch/arm64/kvm/sdei.c
> @@ -931,6 +931,177 @@ void kvm_sdei_create_vcpu(struct kvm_vcpu *vcpu)
>       vcpu->arch.sdei = vsdei;
>  }
>  
> +static long kvm_sdei_set_event(struct kvm *kvm,
> +                            struct kvm_sdei_event_state *kse_state)
> +{
> +     struct kvm_sdei_kvm *ksdei = kvm->arch.sdei;
> +     struct kvm_sdei_event *kse = NULL;
> +
> +     if (!kvm_sdei_is_valid_event_num(kse_state->num))
> +             return -EINVAL;
> +
> +     if (!(kse_state->type == SDEI_EVENT_TYPE_SHARED ||
> +           kse_state->type == SDEI_EVENT_TYPE_PRIVATE))
> +             return -EINVAL;
> +
> +     if (!(kse_state->priority == SDEI_EVENT_PRIORITY_NORMAL ||
> +           kse_state->priority == SDEI_EVENT_PRIORITY_CRITICAL))
> +             return -EINVAL;
> +
> +     kse = kvm_sdei_find_event(kvm, kse_state->num);
> +     if (kse)
> +             return -EEXIST;
> +
> +     kse = kzalloc(sizeof(*kse), GFP_KERNEL);
> +     if (!kse)
> +             return -ENOMEM;
userspace can exhaust the mem since there is no limit. There must be a max.

> +
> +     kse->state = *kse_state;
> +     kse->kvm = kvm;
> +     list_add_tail(&kse->link, &ksdei->events);
> +
> +     return 0;
> +}
> +
> +static long kvm_sdei_get_kevent_count(struct kvm *kvm, int *count)
> +{
> +     struct kvm_sdei_kvm *ksdei = kvm->arch.sdei;
> +     struct kvm_sdei_kvm_event *kske = NULL;
> +     int total = 0;
> +
> +     list_for_each_entry(kske, &ksdei->kvm_events, link) {
> +             total++;
> +     }
> +
> +     *count = total;
> +     return 0;
> +}
> +
> +static long kvm_sdei_get_kevent(struct kvm *kvm,
> +                             struct kvm_sdei_kvm_event_state *kske_state)
> +{
> +     struct kvm_sdei_kvm *ksdei = kvm->arch.sdei;
> +     struct kvm_sdei_kvm_event *kske = NULL;
> +
> +     /*
> +      * The first entry is fetched if the event number is invalid.
> +      * Otherwise, the next entry is fetched.
why don't we return an error? What is the point returning the next entry?
> +      */
> +     if (!kvm_sdei_is_valid_event_num(kske_state->num)) {
> +             kske = list_first_entry_or_null(&ksdei->kvm_events,
> +                             struct kvm_sdei_kvm_event, link);
> +     } else {
> +             kske = kvm_sdei_find_kvm_event(kvm, kske_state->num);
> +             if (kske && !list_is_last(&kske->link, &ksdei->kvm_events))
> +                     kske = list_next_entry(kske, link);
Sorry I don't get why we return the next one?
> +             else
> +                     kske = NULL;
> +     }
> +
> +     if (!kske)
> +             return -ENOENT;
> +
> +     *kske_state = kske->state;
> +
> +     return 0;
> +}
> +
> +static long kvm_sdei_set_kevent(struct kvm *kvm,
> +                             struct kvm_sdei_kvm_event_state *kske_state)
> +{
> +     struct kvm_sdei_kvm *ksdei = kvm->arch.sdei;
> +     struct kvm_sdei_event *kse = NULL;
> +     struct kvm_sdei_kvm_event *kske = NULL;
> +
> +     /* Sanity check */
> +     if (!kvm_sdei_is_valid_event_num(kske_state->num))
> +             return -EINVAL;
> +
> +     if (!(kske_state->route_mode == SDEI_EVENT_REGISTER_RM_ANY ||
> +           kske_state->route_mode == SDEI_EVENT_REGISTER_RM_PE))
> +             return -EINVAL;
> +
> +     /* Check if the event number is valid */
> +     kse = kvm_sdei_find_event(kvm, kske_state->num);
> +     if (!kse)
> +             return -ENOENT;
> +
> +     /* Check if the event has been populated */
> +     kske = kvm_sdei_find_kvm_event(kvm, kske_state->num);
> +     if (kske)
> +             return -EEXIST;
> +
> +     kske = kzalloc(sizeof(*kske), GFP_KERNEL);
userspace can exhaust the mem since there is no limit
> +     if (!kske)
> +             return -ENOMEM;
> +
> +     kske->state = *kske_state;
> +     kske->kse   = kse;
> +     kske->kvm   = kvm;
> +     list_add_tail(&kske->link, &ksdei->kvm_events);
> +
> +     return 0;
> +}
> +
> +long kvm_sdei_vm_ioctl(struct kvm *kvm, unsigned long arg)
> +{
> +     struct kvm_sdei_kvm *ksdei = kvm->arch.sdei;
> +     struct kvm_sdei_cmd *cmd = NULL;
> +     void __user *argp = (void __user *)arg;
> +     bool copy = false;
> +     long ret = 0;
> +
> +     /* Sanity check */
> +     if (!ksdei) {
> +             ret = -EPERM;
> +             goto out;
> +     }
> +
> +     cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
> +     if (!cmd) {
> +             ret = -ENOMEM;
> +             goto out;
> +     }
> +
> +     if (copy_from_user(cmd, argp, sizeof(*cmd))) {
> +             ret = -EFAULT;
> +             goto out;
> +     }
> +
> +     spin_lock(&ksdei->lock);
> +
> +     switch (cmd->cmd) {
> +     case KVM_SDEI_CMD_GET_VERSION:
> +             copy = true;
> +             cmd->version = (1 << 16);       /* v1.0.0 */
> +             break;
> +     case KVM_SDEI_CMD_SET_EVENT:
> +             ret = kvm_sdei_set_event(kvm, &cmd->kse_state);
> +             break;
> +     case KVM_SDEI_CMD_GET_KEVENT_COUNT:
> +             copy = true;
> +             ret = kvm_sdei_get_kevent_count(kvm, &cmd->count);
> +             break;
> +     case KVM_SDEI_CMD_GET_KEVENT:
> +             copy = true;
> +             ret = kvm_sdei_get_kevent(kvm, &cmd->kske_state);
> +             break;
> +     case KVM_SDEI_CMD_SET_KEVENT:
> +             ret = kvm_sdei_set_kevent(kvm, &cmd->kske_state);
> +             break;
> +     default:
> +             ret = -EINVAL;
> +     }
> +
> +     spin_unlock(&ksdei->lock);
> +out:
> +     if (!ret && copy && copy_to_user(argp, cmd, sizeof(*cmd)))
> +             ret = -EFAULT;
> +
> +     kfree(cmd);
> +     return ret;
> +}
> +
>  void kvm_sdei_destroy_vcpu(struct kvm_vcpu *vcpu)
>  {
>       struct kvm_sdei_vcpu *vsdei = vcpu->arch.sdei;
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index d9e4aabcb31a..8cf41fd4bf86 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -1679,6 +1679,9 @@ struct kvm_xen_vcpu_attr {
>  #define KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_DATA 0x4
>  #define KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST       0x5
>  
> +/* Available with KVM_CAP_ARM_SDEI */
> +#define KVM_ARM_SDEI_COMMAND _IOWR(KVMIO, 0xce, struct kvm_sdei_cmd)
> +
>  /* Secure Encrypted Virtualization command */
>  enum sev_cmd_id {
>       /* Guest initialization commands */
> 
Eric

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