drivers: hv: kvp: Cleanup the kernel/user protocol

Now, cleanup the user/kernel KVP protocol by using the same structure
definition that is used for host/guest KVP protocol. This simplifies the code.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hv/hv_kvp.c

@@ -71,15 +71,20 @@ kvp_register(void)
 {
 
 	struct cn_msg *msg;
+	struct hv_kvp_msg *kvp_msg;
+	char *version;
 
-	msg = kzalloc(sizeof(*msg) + strlen(HV_DRV_VERSION) + 1 , GFP_ATOMIC);
+	msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg), GFP_ATOMIC);
 
 	if (msg) {
+		kvp_msg = (struct hv_kvp_msg *)msg->data;
+		version = kvp_msg->body.kvp_version;
 		msg->id.idx =  CN_KVP_IDX;
 		msg->id.val = CN_KVP_VAL;
-		msg->seq = KVP_REGISTER;
-		strcpy(msg->data, HV_DRV_VERSION);
-		msg->len = strlen(HV_DRV_VERSION) + 1;
+
+		kvp_msg->kvp_hdr.operation = KVP_OP_REGISTER;
+		strcpy(version, HV_DRV_VERSION);
+		msg->len = sizeof(struct hv_kvp_msg);
 		cn_netlink_send(msg, 0, GFP_ATOMIC);
 		kfree(msg);
 	}
@@ -101,23 +106,24 @@ kvp_work_func(struct work_struct *dummy)
 static void
 kvp_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 {
-	struct hv_ku_msg *message;
+	struct hv_kvp_msg *message;
+	struct hv_kvp_msg_enumerate *data;
 
-	message = (struct hv_ku_msg *)msg->data;
-	if (msg->seq == KVP_REGISTER) {
+	message = (struct hv_kvp_msg *)msg->data;
+	if (message->kvp_hdr.operation == KVP_OP_REGISTER) {
 		pr_info("KVP: user-mode registering done.\n");
 		kvp_register();
 	}
 
-	if (msg->seq == KVP_USER_SET) {
+	if (message->kvp_hdr.operation == KVP_OP_ENUMERATE) {
+		data = &message->body.kvp_enum_data;
 		/*
 		 * Complete the transaction by forwarding the key value
 		 * to the host. But first, cancel the timeout.
 		 */
 		if (cancel_delayed_work_sync(&kvp_work))
-			kvp_respond_to_host(message->kvp_key,
-						message->kvp_value,
-						!strlen(message->kvp_key));
+			kvp_respond_to_host(data->data.key, data->data.value,
+					!strlen(data->data.key));
 	}
 }
 
@@ -125,6 +131,7 @@ static void
 kvp_send_key(struct work_struct *dummy)
 {
 	struct cn_msg *msg;
+	struct hv_kvp_msg *message;
 	int index = kvp_transaction.index;
 
 	msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg) , GFP_ATOMIC);
@@ -132,9 +139,11 @@ kvp_send_key(struct work_struct *dummy)
 	if (msg) {
 		msg->id.idx =  CN_KVP_IDX;
 		msg->id.val = CN_KVP_VAL;
-		msg->seq = KVP_KERNEL_GET;
-		((struct hv_ku_msg *)msg->data)->kvp_index = index;
-		msg->len = sizeof(struct hv_ku_msg);
+
+		message = (struct hv_kvp_msg *)msg->data;
+		message->kvp_hdr.operation = KVP_OP_ENUMERATE;
+		message->body.kvp_enum_data.index = index;
+		msg->len = sizeof(struct hv_kvp_msg);
 		cn_netlink_send(msg, 0, GFP_ATOMIC);
 		kfree(msg);
 	}
@@ -191,7 +200,7 @@ kvp_respond_to_host(char *key, char *value, int error)
 	kvp_msg = (struct hv_kvp_msg *)
 			&recv_buffer[sizeof(struct vmbuspipe_hdr) +
 			sizeof(struct icmsg_hdr)];
-	kvp_data = &kvp_msg->kvp_data;
+	kvp_data = &kvp_msg->body.kvp_enum_data;
 	key_name = key;
 
 	/*
@@ -266,7 +275,7 @@ void hv_kvp_onchannelcallback(void *context)
 				sizeof(struct vmbuspipe_hdr) +
 				sizeof(struct icmsg_hdr)];
 
-			kvp_data = &kvp_msg->kvp_data;
+			kvp_data = &kvp_msg->body.kvp_enum_data;
 
 			/*
 			 * We only support the "get" operation on

include/linux/hyperv.h

@@ -113,30 +113,6 @@
  * (not supported), a NULL key string is returned.
  */
 
-/*
- *
- * The following definitions are shared with the user-mode component; do not
- * change any of this without making the corresponding changes in
- * the KVP user-mode component.
- */
-
-enum hv_ku_op {
-	KVP_REGISTER = 0, /* Register the user mode component */
-	KVP_KERNEL_GET, /* Kernel is requesting the value */
-	KVP_KERNEL_SET, /* Kernel is providing the value */
-	KVP_USER_GET,  /* User is requesting the value */
-	KVP_USER_SET  /* User is providing the value */
-};
-
-struct hv_ku_msg {
-	__u32 kvp_index; /* Key index */
-	__u8  kvp_key[HV_KVP_EXCHANGE_MAX_KEY_SIZE]; /* Key name */
-	__u8  kvp_value[HV_KVP_EXCHANGE_MAX_VALUE_SIZE]; /* Key  value */
-};
-
-
-
-
 
 /*
  * Registry value types.
@@ -149,6 +125,7 @@ enum hv_kvp_exchg_op {
 	KVP_OP_SET,
 	KVP_OP_DELETE,
 	KVP_OP_ENUMERATE,
+	KVP_OP_REGISTER,
 	KVP_OP_COUNT /* Number of operations, must be last. */
 };
 
@@ -182,7 +159,10 @@ struct hv_kvp_msg_enumerate {
 
 struct hv_kvp_msg {
 	struct hv_kvp_hdr	kvp_hdr;
-	struct hv_kvp_msg_enumerate	kvp_data;
+	union {
+		struct hv_kvp_msg_enumerate     kvp_enum_data;
+		char    kvp_version[HV_KVP_EXCHANGE_MAX_KEY_SIZE];
+	} body;
 } __attribute__((packed));
 
 #ifdef __KERNEL__

tools/hv/hv_kvp_daemon.c

@@ -302,7 +302,7 @@ int main(void)
 	struct pollfd pfd;
 	struct nlmsghdr *incoming_msg;
 	struct cn_msg	*incoming_cn_msg;
-	struct hv_ku_msg *hv_msg;
+	struct hv_kvp_msg *hv_msg;
 	char	*p;
 	char	*key_value;
 	char	*key_name;
@@ -340,9 +340,11 @@ int main(void)
 	message = (struct cn_msg *)kvp_send_buffer;
 	message->id.idx = CN_KVP_IDX;
 	message->id.val = CN_KVP_VAL;
-	message->seq = KVP_REGISTER;
+
+	hv_msg = (struct hv_kvp_msg *)message->data;
+	hv_msg->kvp_hdr.operation = KVP_OP_REGISTER;
 	message->ack = 0;
-	message->len = 0;
+	message->len = sizeof(struct hv_kvp_msg);
 
 	len = netlink_send(fd, message);
 	if (len < 0) {
@@ -368,14 +370,15 @@ int main(void)
 
 		incoming_msg = (struct nlmsghdr *)kvp_recv_buffer;
 		incoming_cn_msg = (struct cn_msg *)NLMSG_DATA(incoming_msg);
+		hv_msg = (struct hv_kvp_msg *)incoming_cn_msg->data;
 
-		switch (incoming_cn_msg->seq) {
-		case KVP_REGISTER:
+		switch (hv_msg->kvp_hdr.operation) {
+		case KVP_OP_REGISTER:
 			/*
 			 * Driver is registering with us; stash away the version
 			 * information.
 			 */
-			p = (char *)incoming_cn_msg->data;
+			p = (char *)hv_msg->body.kvp_version;
 			lic_version = malloc(strlen(p) + 1);
 			if (lic_version) {
 				strcpy(lic_version, p);
@@ -386,17 +389,15 @@ int main(void)
 			}
 			continue;
 
-		case KVP_KERNEL_GET:
-			break;
 		default:
-			continue;
+			break;
 		}
 
-		hv_msg = (struct hv_ku_msg *)incoming_cn_msg->data;
-		key_name = (char *)hv_msg->kvp_key;
-		key_value = (char *)hv_msg->kvp_value;
+		hv_msg = (struct hv_kvp_msg *)incoming_cn_msg->data;
+		key_name = (char *)hv_msg->body.kvp_enum_data.data.key;
+		key_value = (char *)hv_msg->body.kvp_enum_data.data.value;
 
-		switch (hv_msg->kvp_index) {
+		switch (hv_msg->body.kvp_enum_data.index) {
 		case FullyQualifiedDomainName:
 			kvp_get_domain_name(key_value,
 					HV_KVP_EXCHANGE_MAX_VALUE_SIZE);
@@ -456,9 +457,8 @@ int main(void)
 
 		incoming_cn_msg->id.idx = CN_KVP_IDX;
 		incoming_cn_msg->id.val = CN_KVP_VAL;
-		incoming_cn_msg->seq = KVP_USER_SET;
 		incoming_cn_msg->ack = 0;
-		incoming_cn_msg->len = sizeof(struct hv_ku_msg);
+		incoming_cn_msg->len = sizeof(struct hv_kvp_msg);
 
 		len = netlink_send(fd, incoming_cn_msg);
 		if (len < 0) {