Drivers: hv: util: Fix a bug in version negotiation code for util services

The current code picked the highest version advertised by the host. WS2012 R2
has implemented a protocol version for KVP that is not compatible with prior
protocol versions of KVP. Fix the bug in the current code by explicitly specifying
the protocol version that the guest can support.

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>

1 files changed, 9 insertions, 1 deletions

diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index fae8bac907ef..49949079cf47 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -27,6 +27,14 @@
 
 #include <linux/types.h>
 
+/*
+ * Framework version for util services.
+ */
+
+#define UTIL_FW_MAJOR  3
+#define UTIL_FW_MINOR  0
+#define UTIL_FW_MAJOR_MINOR     (UTIL_FW_MAJOR << 16 | UTIL_FW_MINOR)
+
 
 /*
  * Implementation of host controlled snapshot of the guest.
@@ -1494,7 +1502,7 @@ struct hyperv_service_callback {
 };
 
 #define MAX_SRV_VER     0x7ffffff
-extern void vmbus_prep_negotiate_resp(struct icmsg_hdr *,
+extern bool vmbus_prep_negotiate_resp(struct icmsg_hdr *,
                                         struct icmsg_negotiate *, u8 *, int,
                                         int);