2 files changed, 46 insertions, 7 deletions

diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 114050dc8e28..ac71653abb77 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -321,10 +321,32 @@ static void process_chn_event(u32 relid)
 void vmbus_on_event(unsigned long data)
 {
         u32 dword;
-        u32 maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5;
+        u32 maxdword;
         int bit;
         u32 relid;
-        u32 *recv_int_page = vmbus_connection.recv_int_page;
+        u32 *recv_int_page = NULL;
+        void *page_addr;
+        int cpu = smp_processor_id();
+        union hv_synic_event_flags *event;
+
+        if ((vmbus_proto_version == VERSION_WS2008) ||
+                (vmbus_proto_version == VERSION_WIN7)) {
+                maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5;
+                recv_int_page = vmbus_connection.recv_int_page;
+        } else {
+                /*
+                 * When the host is win8 and beyond, the event page
+                 * can be directly checked to get the id of the channel
+                 * that has the interrupt pending.
+                 */
+                maxdword = HV_EVENT_FLAGS_DWORD_COUNT;
+                page_addr = hv_context.synic_event_page[cpu];
+                event = (union hv_synic_event_flags *)page_addr +
+                                                 VMBUS_MESSAGE_SINT;
+                recv_int_page = event->flags32;
+        }
+
+
 
         /* Check events */
         if (!recv_int_page)
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 8e1a9ec53003..c583a0403c53 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -460,15 +460,32 @@ static irqreturn_t vmbus_isr(int irq, void *dev_id)
          * Hyper-V, and the Windows team suggested we do the same.
          */
 
-        page_addr = hv_context.synic_event_page[cpu];
-        event = (union hv_synic_event_flags *)page_addr + VMBUS_MESSAGE_SINT;
+        if ((vmbus_proto_version == VERSION_WS2008) ||
+                (vmbus_proto_version == VERSION_WIN7)) {
 
-        /* Since we are a child, we only need to check bit 0 */
-        if (sync_test_and_clear_bit(0, (unsigned long *) &event->flags32[0])) {
+                page_addr = hv_context.synic_event_page[cpu];
+                event = (union hv_synic_event_flags *)page_addr +
+                                         VMBUS_MESSAGE_SINT;
+
+                /* Since we are a child, we only need to check bit 0 */
+                if (sync_test_and_clear_bit(0,
+                        (unsigned long *) &event->flags32[0])) {
+                        handled = true;
+                }
+        } else {
+                /*
+                 * Our host is win8 or above. The signaling mechanism
+                 * has changed and we can directly look at the event page.
+                 * If bit n is set then we have an interrup on the channel
+                 * whose id is n.
+                 */
                 handled = true;
-                tasklet_schedule(&event_dpc);
         }
 
+        if (handled)
+                tasklet_schedule(&event_dpc);
+
+
         page_addr = hv_context.synic_message_page[cpu];
         msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;