[PATCH v4 16/21] KVM: arm64: Support SDEI ioctl commands on VM

[Gavin Shan]

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:

   * KVM_SDEI_CMD_GET_VERSION
     Retrieve the version of current implementation
   * 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

Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx>
---
 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;
+
+	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.
+	 */
+	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);
+		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);
+	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 */
-- 
2.23.0