[3.11.y.z extended stable] Patch "Drivers: hv: vmbus: Negotiate version 3.0 when running on ws2012r2 hosts" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    Drivers: hv: vmbus: Negotiate version 3.0 when running on ws2012r2 hosts

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 1759a73808a5259a2bdea66a990f53b4d32e86a2 Mon Sep 17 00:00:00 2001
From: "K. Y. Srinivasan" <kys at microsoft.com>
Date: Thu, 3 Apr 2014 18:02:45 -0700
Subject: Drivers: hv: vmbus: Negotiate version 3.0 when running on ws2012r2
 hosts

commit 03367ef5ea811475187a0732aada068919e14d61 upstream.

Only ws2012r2 hosts support the ability to reconnect to the host on VMBUS. This functionality
is needed by kexec in Linux. To use this functionality we need to negotiate version 3.0 of the
VMBUS protocol.

Signed-off-by: K. Y. Srinivasan <kys at microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
[ luis: backported to 3.11: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/hv/connection.c | 5 ++++-
 include/linux/hyperv.h  | 4 +++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index bf07435..8e8522d 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -55,6 +55,9 @@ static __u32 vmbus_get_next_version(__u32 current_version)
 	case (VERSION_WIN8):
 		return VERSION_WIN7;

+	case (VERSION_WIN8_1):
+		return VERSION_WIN8;
+
 	case (VERSION_WS2008):
 	default:
 		return VERSION_INVAL;
@@ -79,7 +82,7 @@ static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo,
 	msg->monitor_page2 = virt_to_phys(
 			(void *)((unsigned long)vmbus_connection.monitor_pages +
 				 PAGE_SIZE));
-	if (version == VERSION_WIN8)
+	if (version == VERSION_WIN8_1)
 		msg->target_vcpu = hv_context.vp_index[smp_processor_id()];

 	/*
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index e0e64d1..204eca1 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -483,15 +483,17 @@ hv_get_ringbuffer_availbytes(struct hv_ring_buffer_info *rbi,
  * 0 . 13 (Windows Server 2008)
  * 1 . 1  (Windows 7)
  * 2 . 4  (Windows 8)
+ * 3 . 0  (Windows 8 R2)
  */

 #define VERSION_WS2008  ((0 << 16) | (13))
 #define VERSION_WIN7    ((1 << 16) | (1))
 #define VERSION_WIN8    ((2 << 16) | (4))
+#define VERSION_WIN8_1    ((3 << 16) | (0))

 #define VERSION_INVAL -1

-#define VERSION_CURRENT VERSION_WIN8
+#define VERSION_CURRENT VERSION_WIN8_1

 /* Make maximum size of pipe payload of 16K */
 #define MAX_PIPE_DATA_PAYLOAD		(sizeof(u8) * 16384)
--
1.9.1