Drivers: hv: vmbus: Implement the protocol for tearing down vmbus state
Implement the protocol for tearing down the monitor state established with
the host.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 865a3af..4b9d89a 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -422,6 +422,30 @@
}
/*
+ * vmbus_unload_response - Handler for the unload response.
+ */
+static void vmbus_unload_response(struct vmbus_channel_message_header *hdr)
+{
+ /*
+ * This is a global event; just wakeup the waiting thread.
+ * Once we successfully unload, we can cleanup the monitor state.
+ */
+ complete(&vmbus_connection.unload_event);
+}
+
+void vmbus_initiate_unload(void)
+{
+ struct vmbus_channel_message_header hdr;
+
+ init_completion(&vmbus_connection.unload_event);
+ memset(&hdr, 0, sizeof(struct vmbus_channel_message_header));
+ hdr.msgtype = CHANNELMSG_UNLOAD;
+ vmbus_post_msg(&hdr, sizeof(struct vmbus_channel_message_header));
+
+ wait_for_completion(&vmbus_connection.unload_event);
+}
+
+/*
* vmbus_onoffer - Handler for channel offers from vmbus in parent partition.
*
*/
@@ -717,6 +741,7 @@
{CHANNELMSG_INITIATE_CONTACT, 0, NULL},
{CHANNELMSG_VERSION_RESPONSE, 1, vmbus_onversion_response},
{CHANNELMSG_UNLOAD, 0, NULL},
+ {CHANNELMSG_UNLOAD_RESPONSE, 1, vmbus_unload_response},
};
/*
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index b27220a..acd50e9 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -227,6 +227,11 @@
void vmbus_disconnect(void)
{
+ /*
+ * First send the unload request to the host.
+ */
+ vmbus_initiate_unload();
+
if (vmbus_connection.work_queue) {
drain_workqueue(vmbus_connection.work_queue);
destroy_workqueue(vmbus_connection.work_queue);
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 138d663..cddc0c9 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -647,6 +647,7 @@
atomic_t next_gpadl_handle;
+ struct completion unload_event;
/*
* Represents channel interrupts. Each bit position represents a
* channel. When a channel sends an interrupt via VMBUS, it finds its
@@ -741,6 +742,7 @@
int hv_fcopy_init(struct hv_util_service *);
void hv_fcopy_deinit(void);
void hv_fcopy_onchannelcallback(void *);
+void vmbus_initiate_unload(void);
static inline void hv_poll_channel(struct vmbus_channel *channel,
void (*cb)(void *))
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 7870a90..2b56260 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -1106,6 +1106,7 @@
vmbus_connection.conn_state = DISCONNECTED;
hv_synic_clockevents_cleanup();
+ vmbus_disconnect();
hv_remove_vmbus_irq();
vmbus_free_channels();
if (ms_hyperv.features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
@@ -1118,7 +1119,6 @@
smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1);
acpi_bus_unregister_driver(&vmbus_acpi_driver);
hv_cpu_hotplug_quirk(false);
- vmbus_disconnect();
}
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index e29ccdd..ea93486 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -389,6 +389,7 @@
CHANNELMSG_INITIATE_CONTACT = 14,
CHANNELMSG_VERSION_RESPONSE = 15,
CHANNELMSG_UNLOAD = 16,
+ CHANNELMSG_UNLOAD_RESPONSE = 17,
CHANNELMSG_COUNT
};
