[PATCH 10/15] hyperv: uapi-fy PostMessage and SignalEvent hypercall structures

[Roman Kagan <rkagan@virtuozzo.com>]

Expose structures used for PostMessage and SignalEvent hypercalls in a
uapi header.  While doing so, simplify alignment handling and drop
unnecessary complications in the connectionid field.

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
---
 arch/x86/include/uapi/asm/hyperv.h | 18 ++++++++++++++++++
 drivers/hv/hyperv_vmbus.h          | 16 ++--------------
 include/linux/hyperv.h             | 24 +-----------------------
 drivers/hv/channel_mgmt.c          | 14 ++++----------
 drivers/hv/connection.c            |  9 +++------
 drivers/hv/hv.c                    |  2 +-
 drivers/hv/vmbus_drv.c             |  2 +-
 7 files changed, 30 insertions(+), 55 deletions(-)

diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h
index 749fbb25..eb8d42a 100644
--- a/arch/x86/include/uapi/asm/hyperv.h
+++ b/arch/x86/include/uapi/asm/hyperv.h
@@ -378,4 +378,22 @@ struct hv_synic_event_flags_page {
 	struct hv_synic_event_flags sintevent_flags[HV_SYNIC_SINT_COUNT];
 };
 
+#define HV_HYPERCALL_PARAM_ALIGN	8
+
+/* Definition of the hv_post_message hypercall input structure. */
+struct hv_input_post_message {
+	__u32 connectionid;
+	__u32 reserved;
+	__u32 message_type;
+	__u32 payload_size;
+	__u64 payload[HV_MESSAGE_PAYLOAD_BYTE_COUNT];
+} __attribute__((aligned(HV_HYPERCALL_PARAM_ALIGN)));
+
+/* Definition of the hv_signal_event hypercall input structure. */
+struct hv_input_signal_event {
+	__u32 connectionid;
+	__u16 flag_number;
+	__u16 rsvdz;
+} __attribute__((aligned(HV_HYPERCALL_PARAM_ALIGN)));
+
 #endif
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index ac73832..a96f021 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -104,7 +104,7 @@ union hv_monitor_trigger_group {
 };
 
 struct hv_monitor_parameter {
-	union hv_connection_id connectionid;
+	u32 connectionid;
 	u16 flagnumber;
 	u16 rsvdz;
 };
@@ -154,15 +154,6 @@ struct hv_monitor_page {
 	u8 rsvdz4[1984];
 };
 
-/* Definition of the hv_post_message hypercall input structure. */
-struct hv_input_post_message {
-	union hv_connection_id connectionid;
-	u32 reserved;
-	u32 message_type;
-	u32 payload_size;
-	u64 payload[HV_MESSAGE_PAYLOAD_QWORD_COUNT];
-};
-
 /*
  * Versioning definitions used for guests reporting themselves to the
  * hypervisor, and visa versa.
@@ -248,9 +239,6 @@ static inline  __u64 generate_guest_id(__u8 d_info1, __u32 kernel_version,
 #define HV_CAPS_MAX			8
 
 
-#define HV_HYPERCALL_PARAM_ALIGN	sizeof(u64)
-
-
 /* Service definitions */
 
 #define HV_SERVICE_PARENT_PORT				(0)
@@ -351,7 +339,7 @@ extern int hv_init(void);
 
 extern void hv_cleanup(bool crash);
 
-extern int hv_post_message(union hv_connection_id connection_id,
+extern int hv_post_message(u32 connection_id,
 			 enum hv_message_type message_type,
 			 void *payload, size_t payload_size);
 
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 42fe43f..e92446e 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -648,27 +648,6 @@ 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;
-};
-
 enum hv_signal_policy {
 	HV_SIGNAL_POLICY_DEFAULT = 0,
 	HV_SIGNAL_POLICY_EXPLICIT,
@@ -755,8 +734,7 @@ 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;
+	struct hv_input_signal_event sig_event;
 
 	/*
 	 * Starting with win8, this field will be used to specify
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 49eaae2..4a5cc11 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -766,20 +766,14 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
 	/*
 	 * 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;
+	newchannel->sig_event.connectionid = 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 =
+		newchannel->sig_event.connectionid =
 				offer->connection_id;
 	}
 
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index d38b27f..16ae977 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -418,21 +418,18 @@ void vmbus_on_event(unsigned long data)
  */
 int vmbus_post_msg(void *buffer, size_t buflen)
 {
-	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;
-
 	/*
 	 * hv_post_message() can have transient failures because of
 	 * insufficient resources. Retry the operation a couple of
 	 * times before giving up.
 	 */
 	while (retries < 20) {
-		ret = hv_post_message(conn_id, HVMSG_VMBUS, buffer, buflen);
+		ret = hv_post_message(VMBUS_MESSAGE_CONNECTION_ID, HVMSG_VMBUS,
+				      buffer, buflen);
 
 		switch (ret) {
 		case HV_STATUS_INVALID_CONNECTION_ID:
@@ -472,6 +469,6 @@ void vmbus_set_event(struct vmbus_channel *channel)
 		set_bit(child_relid,
 			(unsigned long *)vmbus_connection.send_int_page);
 
-	hv_do_hypercall(HVCALL_SIGNAL_EVENT, channel->sig_event, NULL);
+	hv_do_hypercall(HVCALL_SIGNAL_EVENT, &channel->sig_event, NULL);
 }
 EXPORT_SYMBOL_GPL(vmbus_set_event);
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 7d2a3d1..b9f50de 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -297,7 +297,7 @@ void hv_cleanup(bool crash)
  *
  * This involves a hypercall.
  */
-int hv_post_message(union hv_connection_id connection_id,
+int hv_post_message(u32 connection_id,
 		  enum hv_message_type message_type,
 		  void *payload, size_t payload_size)
 {
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 7564a7b..f6b626b 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -159,7 +159,7 @@ static u32 channel_conn_id(struct vmbus_channel *channel,
 {
 	u8 monitor_group = channel_monitor_group(channel);
 	u8 monitor_offset = channel_monitor_offset(channel);
-	return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id;
+	return monitor_page->parameter[monitor_group][monitor_offset].connectionid;
 }
 
 static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr,
-- 
2.9.3