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>

3 files changed, 45 insertions, 56 deletions

diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c
index 4a6971e13539..0ef4c1f6ca54 100644
--- a/drivers/hv/hv_kvp.c
+++ b/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
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index b822978ecbc8..75aee6720c1b 100644
--- a/include/linux/hyperv.h
+++ b/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__
diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c
index b75523cde2cd..4ebf70380582 100644
--- a/tools/hv/hv_kvp_daemon.c
+++ b/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) {