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authorDexuan Cui <decui@microsoft.com>2018-05-12 02:30:33 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-05-14 16:06:48 +0200
commitae20b254306a6a47054ea0eb8444e0bd8e71fe12 (patch)
tree7332e19407319ad6b197a9474f5635010e695b4b /drivers/hv/connection.c
parente19f70aa02f34abd4c5740f761f4694e9a7c8b3d (diff)
downloadlinux-ae20b254306a6a47054ea0eb8444e0bd8e71fe12.tar.bz2
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: Dexuan 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: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hv/connection.c')
-rw-r--r--drivers/hv/connection.c44
1 files changed, 42 insertions, 2 deletions
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 72855182b191..19e046820fda 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -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;
- msg->interrupt_page = virt_to_phys(vmbus_connection.int_page);
+
+ /*
+ * 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
@@ -373,6 +401,18 @@ 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.
*/