Drivers: hv: Add new message types to enhance KVP

Add additional KVP (Key Value Pair) protocol  messages to
enhance KVP functionality for Linux guests on Hyper-V. As part of this,
patch define an explicit version negoitiation message.

Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 31 insertions, 6 deletions

diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c
index 0ef4c1f6ca54..779109b6f4f0 100644
--- a/drivers/hv/hv_kvp.c
+++ b/drivers/hv/hv_kvp.c
@@ -78,7 +78,7 @@ kvp_register(void)
 
         if (msg) {
                 kvp_msg = (struct hv_kvp_msg *)msg->data;
-                version = kvp_msg->body.kvp_version;
+                version = kvp_msg->body.kvp_register.version;
                 msg->id.idx =  CN_KVP_IDX;
                 msg->id.val = CN_KVP_VAL;
 
@@ -122,7 +122,8 @@ kvp_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
                  * to the host. But first, cancel the timeout.
                  */
                 if (cancel_delayed_work_sync(&kvp_work))
-                        kvp_respond_to_host(data->data.key, data->data.value,
+                        kvp_respond_to_host(data->data.key,
+                                         data->data.value,
                                         !strlen(data->data.key));
         }
 }
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index e57a6c6ee0e8..a2d8c547f91b 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -149,7 +149,11 @@ struct hv_kvp_exchg_msg_value {
         __u32 key_size;
         __u32 value_size;
         __u8 key[HV_KVP_EXCHANGE_MAX_KEY_SIZE];
-        __u8 value[HV_KVP_EXCHANGE_MAX_VALUE_SIZE];
+        union {
+                __u8 value[HV_KVP_EXCHANGE_MAX_VALUE_SIZE];
+                __u32 value_u32;
+                __u64 value_u64;
+        };
 } __attribute__((packed));
 
 struct hv_kvp_msg_enumerate {
@@ -157,11 +161,31 @@ struct hv_kvp_msg_enumerate {
         struct hv_kvp_exchg_msg_value data;
 } __attribute__((packed));
 
+struct hv_kvp_msg_get {
+        struct hv_kvp_exchg_msg_value data;
+};
+
+struct hv_kvp_msg_set {
+        struct hv_kvp_exchg_msg_value data;
+};
+
+struct hv_kvp_msg_delete {
+        __u32 key_size;
+        __u8 key[HV_KVP_EXCHANGE_MAX_KEY_SIZE];
+};
+
+struct hv_kvp_register {
+        __u8 version[HV_KVP_EXCHANGE_MAX_KEY_SIZE];
+};
+
 struct hv_kvp_msg {
         struct hv_kvp_hdr       kvp_hdr;
         union {
-                struct hv_kvp_msg_enumerate     kvp_enum_data;
-                char    kvp_version[HV_KVP_EXCHANGE_MAX_KEY_SIZE];
+                struct hv_kvp_msg_get           kvp_get;
+                struct hv_kvp_msg_set           kvp_set;
+                struct hv_kvp_msg_delete        kvp_delete;
+                struct hv_kvp_msg_enumerate     kvp_enum_data;
+                struct hv_kvp_register          kvp_register;
         } body;
 } __attribute__((packed));
 
diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c
index 4ebf70380582..00d3f7c099e0 100644
--- a/tools/hv/hv_kvp_daemon.c
+++ b/tools/hv/hv_kvp_daemon.c
@@ -378,7 +378,7 @@ int main(void)
                          * Driver is registering with us; stash away the version
                          * information.
                          */
-                        p = (char *)hv_msg->body.kvp_version;
+                        p = (char *)hv_msg->body.kvp_register.version;
                         lic_version = malloc(strlen(p) + 1);
                         if (lic_version) {
                                 strcpy(lic_version, p);