Drivers: hv: util: Properly handle version negotiations.

The current version negotiation code is not "future proof". Fix this
by allowing each service the flexibility to either specify the highest
version it can support or it can support the highest version number
the host is offering.

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

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 6c8c4d34093064ac65cad16ea8cbfc191fde053e..2b8b8d4558d247c808a0a8f7f6bfd51601aa31a2 100644 (file)
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -46,37 +46,59 @@ struct vmbus_channel_message_table_entry {
  *
  * @icmsghdrp is of type &struct icmsg_hdr.
  * @negop is of type &struct icmsg_negotiate.
- * Set up and fill in default negotiate response message. This response can
- * come from both the vmbus driver and the hv_utils driver. The current api
- * will respond properly to both Windows 2008 and Windows 2008-R2 operating
- * systems.
+ * Set up and fill in default negotiate response message.
+ *
+ * The max_fw_version specifies the maximum framework version that
+ * we can support and max _srv_version specifies the maximum service
+ * version we can support. A special value MAX_SRV_VER can be
+ * specified to indicate that we can handle the maximum version
+ * exposed by the host.
  *
  * Mainly used by Hyper-V drivers.
  */
 void vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp,
-                              struct icmsg_negotiate *negop, u8 *buf)
+                               struct icmsg_negotiate *negop, u8 *buf,
+                               int max_fw_version, int max_srv_version)
 {
+       int icframe_vercnt;
+       int icmsg_vercnt;
+       int i;
+
        icmsghdrp->icmsgsize = 0x10;
 
        negop = (struct icmsg_negotiate *)&buf[
                sizeof(struct vmbuspipe_hdr) +
                sizeof(struct icmsg_hdr)];
 
-       if (negop->icframe_vercnt == 2 &&
-          negop->icversion_data[1].major == 3) {
-               negop->icversion_data[0].major = 3;
-               negop->icversion_data[0].minor = 0;
-               negop->icversion_data[1].major = 3;
-               negop->icversion_data[1].minor = 0;
-       } else {
-               negop->icversion_data[0].major = 1;
-               negop->icversion_data[0].minor = 0;
-               negop->icversion_data[1].major = 1;
-               negop->icversion_data[1].minor = 0;
+       icframe_vercnt = negop->icframe_vercnt;
+       icmsg_vercnt = negop->icmsg_vercnt;
+
+       /*
+        * Select the framework version number we will
+        * support.
+        */
+
+       for (i = 0; i < negop->icframe_vercnt; i++) {
+               if (negop->icversion_data[i].major <= max_fw_version)
+                       icframe_vercnt = negop->icversion_data[i].major;
+       }
+
+       for (i = negop->icframe_vercnt;
+                (i < negop->icframe_vercnt + negop->icmsg_vercnt); i++) {
+               if (negop->icversion_data[i].major <= max_srv_version)
+                       icmsg_vercnt = negop->icversion_data[i].major;
        }
 
+       /*
+        * Respond with the maximum framework and service
+        * version numbers we can support.
+        */
        negop->icframe_vercnt = 1;
        negop->icmsg_vercnt = 1;
+       negop->icversion_data[0].major = icframe_vercnt;
+       negop->icversion_data[0].minor = 0;
+       negop->icversion_data[1].major = icmsg_vercnt;
+       negop->icversion_data[1].minor = 0;
 }
 
 EXPORT_SYMBOL_GPL(vmbus_prep_negotiate_resp);

diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c
index 6186025209ce95362a42a8b6a65ad98ae99ea2c4..0012eed6d872b0b01dd313d18107879d99b8e142 100644 (file)
--- a/drivers/hv/hv_kvp.c
+++ b/drivers/hv/hv_kvp.c
@@ -394,7 +394,8 @@ void hv_kvp_onchannelcallback(void *context)
                        sizeof(struct vmbuspipe_hdr)];
 
                if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
-                       vmbus_prep_negotiate_resp(icmsghdrp, negop, recv_buffer);
+                       vmbus_prep_negotiate_resp(icmsghdrp, negop,
+                                recv_buffer, MAX_SRV_VER, MAX_SRV_VER);
                } else {
                        kvp_msg = (struct hv_kvp_msg *)&recv_buffer[
                                sizeof(struct vmbuspipe_hdr) +

diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c
index dbb8b8eec2100bc92939f309550b0d00c037c4cb..d3ac6a40118b30eb1033809c7f9198a6dd5c9b17 100644 (file)
--- a/drivers/hv/hv_util.c
+++ b/drivers/hv/hv_util.c
@@ -70,7 +70,8 @@ static void shutdown_onchannelcallback(void *context)
                        sizeof(struct vmbuspipe_hdr)];
 
                if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
-                       vmbus_prep_negotiate_resp(icmsghdrp, negop, shut_txf_buf);
+                       vmbus_prep_negotiate_resp(icmsghdrp, negop,
+                                       shut_txf_buf, MAX_SRV_VER, MAX_SRV_VER);
                } else {
                        shutdown_msg =
                                (struct shutdown_msg_data *)&shut_txf_buf[
@@ -195,7 +196,8 @@ static void timesync_onchannelcallback(void *context)
                                sizeof(struct vmbuspipe_hdr)];
 
                if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
-                       vmbus_prep_negotiate_resp(icmsghdrp, NULL, time_txf_buf);
+                       vmbus_prep_negotiate_resp(icmsghdrp, NULL, time_txf_buf,
+                                               MAX_SRV_VER, MAX_SRV_VER);
                } else {
                        timedatap = (struct ictimesync_data *)&time_txf_buf[
                                sizeof(struct vmbuspipe_hdr) +
@@ -234,7 +236,8 @@ static void heartbeat_onchannelcallback(void *context)
                                sizeof(struct vmbuspipe_hdr)];
 
                if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
-                       vmbus_prep_negotiate_resp(icmsghdrp, NULL, hbeat_txf_buf);
+                       vmbus_prep_negotiate_resp(icmsghdrp, NULL,
+                               hbeat_txf_buf, MAX_SRV_VER, MAX_SRV_VER);
                } else {
                        heartbeat_msg =
                                (struct heartbeat_msg_data *)&hbeat_txf_buf[

diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 5852545e6bba77423c16e4577efc40c4450131a9..22172bd43745b0a2077cef3698d873a6fbdec2c8 100644 (file)
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1035,8 +1035,10 @@ struct hyperv_service_callback {
        void (*callback) (void *context);
 };
 
+#define MAX_SRV_VER    0x7ffffff
 extern void vmbus_prep_negotiate_resp(struct icmsg_hdr *,
-                                     struct icmsg_negotiate *, u8 *);
+                                       struct icmsg_negotiate *, u8 *, int,
+                                       int);
 
 int hv_kvp_init(struct hv_util_service *);
 void hv_kvp_deinit(void);