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Commit ae20b254 authored by Dexuan Cui's avatar Dexuan Cui Committed by Greg Kroah-Hartman
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Drivers: hv: vmbus: enable VMBus protocol version 5.0 



With VMBus protocol 5.0, we're able to better support new features, e.g.
running two or more VMBus drivers simultaneously in a single VM -- note:
we can't simply load the current VMBus driver twice, instead, a secondary
VMBus driver must be implemented.

This patch adds the support for the new VMBus protocol, which is available
on new Windows hosts, by:

1) We still use SINT2 for compatibility;
2) We must use Connection ID 4 for the Initiate Contact Message, and for
subsequent messages, we must use the Message Connection ID field in
the host-returned VersionResponse Message.

Notes for developers of the secondary VMBus driver:
1) Must use VMBus protocol 5.0 as well;
2) Must use a different SINT number that is not in use.
3) Must use Connection ID 4 for the Initiate Contact Message, and for
subsequent messages, must use the Message Connection ID field in
the host-returned VersionResponse Message.
4) It's possible that the primary VMBus driver using protocol version 4.0
can work with a secondary VMBus driver using protocol version 5.0, but it's
recommended that both should use 5.0 for new Hyper-V features in the future.

Signed-off-by: default avatarDexuan Cui <decui@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent e19f70aa

drivers/hv/connection.c

+42 −2
Original line number Diff line number Diff line
@@ -63,6 +63,9 @@ static __u32 vmbus_get_next_version(__u32 current_version) 
	case (VERSION_WIN10):

		return VERSION_WIN8_1;



	case (VERSION_WIN10_V5):

		return VERSION_WIN10;



	case (VERSION_WS2008):

	default:

		return VERSION_INVAL;
@@ -80,9 +83,29 @@ static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, 


	msg = (struct vmbus_channel_initiate_contact *)msginfo->msg;



	memset(msg, 0, sizeof(*msg));

	msg->header.msgtype = CHANNELMSG_INITIATE_CONTACT;

	msg->vmbus_version_requested = version;



	/*

	 * VMBus protocol 5.0 (VERSION_WIN10_V5) requires that we must use

	 * VMBUS_MESSAGE_CONNECTION_ID_4 for the Initiate Contact Message,

	 * and for subsequent messages, we must use the Message Connection ID

	 * field in the host-returned Version Response Message. And, with

	 * VERSION_WIN10_V5, we don't use msg->interrupt_page, but we tell

	 * the host explicitly that we still use VMBUS_MESSAGE_SINT(2) for

	 * compatibility.

	 *

	 * On old hosts, we should always use VMBUS_MESSAGE_CONNECTION_ID (1).

	 */

	if (version >= VERSION_WIN10_V5) {

		msg->msg_sint = VMBUS_MESSAGE_SINT;

		vmbus_connection.msg_conn_id = VMBUS_MESSAGE_CONNECTION_ID_4;

	} else {

		msg->interrupt_page = virt_to_phys(vmbus_connection.int_page);

		vmbus_connection.msg_conn_id = VMBUS_MESSAGE_CONNECTION_ID;

	}



	msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages[0]);

	msg->monitor_page2 = virt_to_phys(vmbus_connection.monitor_pages[1]);

	/*
@@ -137,6 +160,10 @@ static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, 
	/* Check if successful */

	if (msginfo->response.version_response.version_supported) {

		vmbus_connection.conn_state = CONNECTED;



		if (version >= VERSION_WIN10_V5)

			vmbus_connection.msg_conn_id =

				msginfo->response.version_response.msg_conn_id;

	} else {

		return -ECONNREFUSED;

	}
@@ -354,13 +381,14 @@ void vmbus_on_event(unsigned long data) 
 */

int vmbus_post_msg(void *buffer, size_t buflen, bool can_sleep)

{

	struct vmbus_channel_message_header *hdr;

	union hv_connection_id conn_id;

	int ret = 0;

	int retries = 0;

	u32 usec = 1;



	conn_id.asu32 = 0;

	conn_id.u.id = VMBUS_MESSAGE_CONNECTION_ID;

	conn_id.u.id = vmbus_connection.msg_conn_id;



	/*

	 * hv_post_message() can have transient failures because of
@@ -372,6 +400,18 @@ int vmbus_post_msg(void *buffer, size_t buflen, bool can_sleep) 


		switch (ret) {

		case HV_STATUS_INVALID_CONNECTION_ID:

			/*

			 * See vmbus_negotiate_version(): VMBus protocol 5.0

			 * requires that we must use

			 * VMBUS_MESSAGE_CONNECTION_ID_4 for the Initiate

			 * Contact message, but on old hosts that only

			 * support VMBus protocol 4.0 or lower, here we get

			 * HV_STATUS_INVALID_CONNECTION_ID and we should

			 * return an error immediately without retrying.

			 */

			hdr = (struct vmbus_channel_message_header *)buffer;

			if (hdr->msgtype == CHANNELMSG_INITIATE_CONTACT)

				return -EINVAL;

			/*

			 * We could get this if we send messages too

			 * frequently.

drivers/hv/hyperv_vmbus.h

+3 −0
Original line number Diff line number Diff line
@@ -187,6 +187,7 @@ struct hv_input_post_message { 


enum {

	VMBUS_MESSAGE_CONNECTION_ID	= 1,

	VMBUS_MESSAGE_CONNECTION_ID_4	= 4,

	VMBUS_MESSAGE_PORT_ID		= 1,

	VMBUS_EVENT_CONNECTION_ID	= 2,

	VMBUS_EVENT_PORT_ID		= 2,
@@ -302,6 +303,8 @@ struct vmbus_connection { 
	 */

	int connect_cpu;



	u32 msg_conn_id;



	atomic_t offer_in_progress;



	enum vmbus_connect_state conn_state;

include/linux/hyperv.h

+24 −2
Original line number Diff line number Diff line
@@ -163,6 +163,7 @@ static inline u32 hv_get_bytes_to_write(const struct hv_ring_buffer_info *rbi) 
 * 2 . 4  (Windows 8)

 * 3 . 0  (Windows 8 R2)

 * 4 . 0  (Windows 10)

 * 5 . 0  (Newer Windows 10)

 */



#define VERSION_WS2008  ((0 << 16) | (13))
@@ -170,10 +171,11 @@ static inline u32 hv_get_bytes_to_write(const struct hv_ring_buffer_info *rbi) 
#define VERSION_WIN8    ((2 << 16) | (4))

#define VERSION_WIN8_1    ((3 << 16) | (0))

#define VERSION_WIN10	((4 << 16) | (0))

#define VERSION_WIN10_V5 ((5 << 16) | (0))



#define VERSION_INVAL -1



#define VERSION_CURRENT VERSION_WIN10

#define VERSION_CURRENT VERSION_WIN10_V5



/* Make maximum size of pipe payload of 16K */

#define MAX_PIPE_DATA_PAYLOAD		(sizeof(u8) * 16384)
@@ -570,7 +572,14 @@ struct vmbus_channel_initiate_contact { 
	struct vmbus_channel_message_header header;

	u32 vmbus_version_requested;

	u32 target_vcpu; /* The VCPU the host should respond to */

	union {

		u64 interrupt_page;

		struct {

			u8	msg_sint;

			u8	padding1[3];

			u32	padding2;

		};

	};

	u64 monitor_page1;

	u64 monitor_page2;

} __packed;
@@ -585,6 +594,19 @@ struct vmbus_channel_tl_connect_request { 
struct vmbus_channel_version_response {

	struct vmbus_channel_message_header header;

	u8 version_supported;



	u8 connection_state;

	u16 padding;



	/*

	 * On new hosts that support VMBus protocol 5.0, we must use

	 * VMBUS_MESSAGE_CONNECTION_ID_4 for the Initiate Contact Message,

	 * and for subsequent messages, we must use the Message Connection ID

	 * field in the host-returned Version Response Message.

	 *

	 * On old hosts, we should always use VMBUS_MESSAGE_CONNECTION_ID (1).

	 */

	u32 msg_conn_id;

} __packed;



enum vmbus_channel_state {