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>
diff --git a/drivers/hv/hv_snapshot.c b/drivers/hv/hv_snapshot.c
index 8ad5653..e4572f3 100644
--- a/drivers/hv/hv_snapshot.c
+++ b/drivers/hv/hv_snapshot.c
@@ -24,6 +24,10 @@
#include <linux/workqueue.h>
#include <linux/hyperv.h>
+#define VSS_MAJOR 5
+#define VSS_MINOR 0
+#define VSS_MAJOR_MINOR (VSS_MAJOR << 16 | VSS_MINOR)
+
/*
@@ -186,18 +190,8 @@
if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
vmbus_prep_negotiate_resp(icmsghdrp, negop,
- recv_buffer, MAX_SRV_VER, MAX_SRV_VER);
- /*
- * We currently negotiate the highest number the
- * host has presented. If this version is not
- * atleast 5.0, reject.
- */
- negop = (struct icmsg_negotiate *)&recv_buffer[
- sizeof(struct vmbuspipe_hdr) +
- sizeof(struct icmsg_hdr)];
-
- if (negop->icversion_data[1].major < 5)
- negop->icframe_vercnt = 0;
+ recv_buffer, UTIL_FW_MAJOR_MINOR,
+ VSS_MAJOR_MINOR);
} else {
vss_msg = (struct hv_vss_msg *)&recv_buffer[
sizeof(struct vmbuspipe_hdr) +