Drivers: hv: Cleanup vmbus_set_event() to support win7 and beyond

On win7 (ws2008 R2) and beyond, we have the notion of having dedicated interrupts on
a per-channel basis. When a channel has a dedicated interrupt assigned, there is no need
to set the interrupt bit in the shared page. Implement this optimization.

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>

1 files changed, 8 insertions, 5 deletions

diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 56b14e57bdd8..114050dc8e28 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -383,10 +383,13 @@ int vmbus_post_msg(void *buffer, size_t buflen)
 int vmbus_set_event(struct vmbus_channel *channel)
 {
         u32 child_relid = channel->offermsg.child_relid;
-        /* Each u32 represents 32 channels */
-        sync_set_bit(child_relid & 31,
-                (unsigned long *)vmbus_connection.send_int_page +
-                (child_relid >> 5));
 
-        return hv_signal_event(hv_context.signal_event_param);
+        if (!channel->is_dedicated_interrupt) {
+                /* Each u32 represents 32 channels */
+                sync_set_bit(child_relid & 31,
+                        (unsigned long *)vmbus_connection.send_int_page +
+                        (child_relid >> 5));
+        }
+
+        return hv_signal_event(channel->sig_event);
 }