Drivers: hv: Manage signaling state on a per-connection basis

The current code has a global handle for supporting signaling of the host
from guest. Make this a per-channel attribute as on some versions of the
host we can signal on per-channel handle.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hv/channel_mgmt.c

@@ -282,6 +282,26 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
 	 */
 	newchannel->batched_reading = true;
 
+	/*
+	 * Setup state for signalling the host.
+	 */
+	newchannel->sig_event = (struct hv_input_signal_event *)
+				(ALIGN((unsigned long)
+				&newchannel->sig_buf,
+				HV_HYPERCALL_PARAM_ALIGN));
+
+	newchannel->sig_event->connectionid.asu32 = 0;
+	newchannel->sig_event->connectionid.u.id = VMBUS_EVENT_CONNECTION_ID;
+	newchannel->sig_event->flag_number = 0;
+	newchannel->sig_event->rsvdz = 0;
+
+	if (vmbus_proto_version != VERSION_WS2008) {
+		newchannel->is_dedicated_interrupt =
+				(offer->is_dedicated_interrupt != 0);
+		newchannel->sig_event->connectionid.u.id =
+				offer->connection_id;
+	}
+
 	memcpy(&newchannel->offermsg, offer,
 	       sizeof(struct vmbus_channel_offer_channel));
 	newchannel->monitor_grp = (u8)offer->monitorid / 32;

drivers/hv/hyperv_vmbus.h

@@ -101,15 +101,6 @@ enum hv_message_type {
 /* Define invalid partition identifier. */
 #define HV_PARTITION_ID_INVALID		((u64)0x0)
 
-/* Define connection identifier type. */
-union hv_connection_id {
-	u32 asu32;
-	struct {
-		u32 id:24;
-		u32 reserved:8;
-	} u;
-};
-
 /* Define port identifier type. */
 union hv_port_id {
 	u32 asu32;
@@ -338,13 +329,6 @@ struct hv_input_post_message {
 	u64 payload[HV_MESSAGE_PAYLOAD_QWORD_COUNT];
 };
 
-/* Definition of the hv_signal_event hypercall input structure. */
-struct hv_input_signal_event {
-	union hv_connection_id connectionid;
-	u16 flag_number;
-	u16 rsvdz;
-};
-
 /*
  * Versioning definitions used for guests reporting themselves to the
  * hypervisor, and visa versa.
@@ -498,11 +482,6 @@ static const uuid_le VMBUS_SERVICE_ID = {
 
 
 
-struct hv_input_signal_event_buffer {
-	u64 align8;
-	struct hv_input_signal_event event;
-};
-
 struct hv_context {
 	/* We only support running on top of Hyper-V
 	* So at this point this really can only contain the Hyper-V ID

include/linux/hyperv.h

@@ -897,6 +897,27 @@ struct vmbus_close_msg {
 	struct vmbus_channel_close_channel msg;
 };
 
+/* Define connection identifier type. */
+union hv_connection_id {
+	u32 asu32;
+	struct {
+		u32 id:24;
+		u32 reserved:8;
+	} u;
+};
+
+/* Definition of the hv_signal_event hypercall input structure. */
+struct hv_input_signal_event {
+	union hv_connection_id connectionid;
+	u16 flag_number;
+	u16 rsvdz;
+};
+
+struct hv_input_signal_event_buffer {
+	u64 align8;
+	struct hv_input_signal_event event;
+};
+
 struct vmbus_channel {
 	struct list_head listentry;
 
@@ -946,6 +967,10 @@ struct vmbus_channel {
 	 */
 
 	bool batched_reading;
+
+	bool is_dedicated_interrupt;
+	struct hv_input_signal_event_buffer sig_buf;
+	struct hv_input_signal_event *sig_event;
 };
 
 static inline void set_channel_read_state(struct vmbus_channel *c, bool state)