Drivers: hv: vmbus: Introduce table of VMBus protocol versions

The technique used to get the next VMBus version seems increasisly clumsy as the number of VMBus versions increases. Performance is not a concern since this is only done once during system boot; it's just that we'll end up with more lines of code than is really needed. As an alternative, introduce a table with the version numbers listed in order (from the most recent to the oldest). vmbus_connect() loops through the versions listed in the table until it gets an accepted connection or gets to the end of the table (invalid version).

Andrea Parri committed 7 years ago

Commit bedc61a1 parent a99d8083 files · +19 −38Browse files

Unified · Split

3 files

drivers/hv/connection.c +18 −32
drivers/hv/vmbus_drv.c +1 −2
include/linux/hyperv.h +0 −4

drivers/hv/connection.c+18−32

@@ -40,29 +40,17 @@ EXPORT_SYMBOL_GPL(vmbus_connection); · 39 unmodified lines
40	__u32 vmbus_proto_version;	40	__u32 vmbus_proto_version;
41	EXPORT_SYMBOL_GPL(vmbus_proto_version);	41	EXPORT_SYMBOL_GPL(vmbus_proto_version);
42		42
43	static __u32 vmbus_get_next_version(__u32 current_version)	43	/*
44	{	44	* Table of VMBus versions listed from newest to oldest.
45	switch (current_version) {	45	*/
46	case (VERSION_WIN7):	46	static __u32 vmbus_versions[] = {
47	return VERSION_WS2008;	47	VERSION_WIN10_V5,
48		48	VERSION_WIN10,
49	case (VERSION_WIN8):	49	VERSION_WIN8_1,
50	return VERSION_WIN7;	50	VERSION_WIN8,
51		51	VERSION_WIN7,
52	case (VERSION_WIN8_1):	52	VERSION_WS2008
53	return VERSION_WIN8;	53	};
54
55	case (VERSION_WIN10):
56	return VERSION_WIN8_1;
57
58	case (VERSION_WIN10_V5):
59	return VERSION_WIN10;
60
61	case (VERSION_WS2008):
62	default:
63	return VERSION_INVAL;
64	}
65	}
66		54
67	int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version)	55	int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version)
68	{	56	{
@@ -169,8 +157,8 @@ int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version) · 100 unmodified lines
169	*/	157	*/
170	int vmbus_connect(void)	158	int vmbus_connect(void)
171	{	159	{
172	int ret = 0;
173	struct vmbus_channel_msginfo *msginfo = NULL;	160	struct vmbus_channel_msginfo *msginfo = NULL;
		161	int i, ret = 0;
174	__u32 version;	162	__u32 version;
175		163
176	/* Initialize the vmbus connection */	164	/* Initialize the vmbus connection */
@@ -244,21 +232,19 @@ int vmbus_connect(void) · 67 unmodified lines
244	* version.	232	* version.
245	*/	233	*/
246		234
247	version = VERSION_CURRENT;	235	for (i = 0; ; i++) {
		236	if (i == ARRAY_SIZE(vmbus_versions))
		237	goto cleanup;
		238
		239	version = vmbus_versions[i];
248		240
249	do {
250	ret = vmbus_negotiate_version(msginfo, version);	241	ret = vmbus_negotiate_version(msginfo, version);
251	if (ret == -ETIMEDOUT)	242	if (ret == -ETIMEDOUT)
252	goto cleanup;	243	goto cleanup;
253		244
254	if (vmbus_connection.conn_state == CONNECTED)	245	if (vmbus_connection.conn_state == CONNECTED)
255	break;	246	break;
256		247	}
257	version = vmbus_get_next_version(version);
258	} while (version != VERSION_INVAL);
259
260	if (version == VERSION_INVAL)
261	goto cleanup;
262		248
263	vmbus_proto_version = version;	249	vmbus_proto_version = version;
264	pr_info("Vmbus version:%d.%d\n",	250	pr_info("Vmbus version:%d.%d\n",

drivers/hv/vmbus_drv.c+1−2

 	 * We only use the 'vmbus_proto_version', which was in use before
 	 * hibernation, to re-negotiate with the host.
 	 */
-	if (vmbus_proto_version == VERSION_INVAL ||
+	if (!vmbus_proto_version) {
-	    vmbus_proto_version == 0) {
 		pr_err("Invalid proto version = 0x%x\n", vmbus_proto_version);
 		return -EINVAL;
 	}

include/linux/hyperv.h+0−4

@@ -192,10 +192,6 @@ static inline u32 hv_get_avail_to_write_percent( · 191 unmodified lines
192	#define VERSION_WIN10 ((4 << 16) \| (0))	192	#define VERSION_WIN10 ((4 << 16) \| (0))
193	#define VERSION_WIN10_V5 ((5 << 16) \| (0))	193	#define VERSION_WIN10_V5 ((5 << 16) \| (0))
194		194
195	#define VERSION_INVAL -1
196
197	#define VERSION_CURRENT VERSION_WIN10_V5
198
199	/* Make maximum size of pipe payload of 16K */	195	/* Make maximum size of pipe payload of 16K */
200	#define MAX_PIPE_DATA_PAYLOAD (sizeof(u8) * 16384)	196	#define MAX_PIPE_DATA_PAYLOAD (sizeof(u8) * 16384)
201		197

Drivers: hv: vmbus: Introduce table of VMBus protocol versions

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