[Spice-devel] [PATCH 9/9] chardev: learn to keep running when vm is stopped

[Marc-André Lureau]

All chardev channels are stopped when calling spice_server_vm_stop(),
which prevents them from doing any i/o.

However, the Spice block device channel needs to keep running even when
the VM is stopped. It is entirely drived by the server, so it is
entirely to the server to deal with the channel running state (finish
all outstanding operations or block io).
---
 server/char_device.c | 11 ++++++++++-
 server/char_device.h |  1 +
 server/reds.c        |  1 +
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/server/char_device.c b/server/char_device.c
index 0cd5106..7b4c3f8 100644
--- a/server/char_device.c
+++ b/server/char_device.c
@@ -45,6 +45,7 @@ struct SpiceCharDeviceClientState {
 };
 
 struct SpiceCharDeviceState {
+    int non_stop;
     int running;
     int active; /* has read/write been performed since the device was started */
     int wait_for_migrate_data;
@@ -803,12 +804,20 @@ void spice_char_device_start(SpiceCharDeviceState *dev)
 
 void spice_char_device_stop(SpiceCharDeviceState *dev)
 {
-    spice_debug("dev_state %p", dev);
+    spice_debug("char_device_stop %p: non_stop:%d", dev, dev->non_stop);
+
+    if (dev->non_stop)
+        return;
     dev->running = FALSE;
     dev->active = FALSE;
     core->timer_cancel(dev->write_to_dev_timer);
 }
 
+void spice_char_device_set_non_stop(SpiceCharDeviceState *dev, int non_stop)
+{
+    dev->non_stop = non_stop;
+}
+
 void spice_char_device_reset(SpiceCharDeviceState *dev)
 {
     RingItem *client_item;
diff --git a/server/char_device.h b/server/char_device.h
index c17a40d..e2b6c63 100644
--- a/server/char_device.h
+++ b/server/char_device.h
@@ -162,6 +162,7 @@ void spice_char_device_client_remove(SpiceCharDeviceState *dev,
 int spice_char_device_client_exists(SpiceCharDeviceState *dev,
                                     RedClient *client);
 
+void spice_char_device_set_non_stop(SpiceCharDeviceState *dev, int non_stop);
 void spice_char_device_start(SpiceCharDeviceState *dev);
 void spice_char_device_stop(SpiceCharDeviceState *dev);
 
diff --git a/server/reds.c b/server/reds.c
index d9e04de..f1bad0c 100644
--- a/server/reds.c
+++ b/server/reds.c
@@ -3669,6 +3669,7 @@ static int spice_server_char_device_add_interface(SpiceServer *s,
     }
     else if (strcmp(char_device->subtype, SUBTYPE_NBD) == 0) {
         dev_state = spicevmc_device_connect(char_device, SPICE_CHANNEL_NBD);
+        spice_char_device_set_non_stop(dev_state, TRUE);
     }
     else if (strcmp(char_device->subtype, SUBTYPE_PORT) == 0) {
         dev_state = spicevmc_device_connect(char_device, SPICE_CHANNEL_PORT);
-- 
1.8.3.1