[Qemu-devel] [RFC 27/29] vhost+postcopy: Wire up POSTCOPY_END notify

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <address@hidden>

Wire up a call to VHOST_USER_POSTCOPY_END message to the vhost clients
right before we ask the listener thread to shutdown.

Signed-off-by: Dr. David Alan Gilbert <address@hidden>
---
 hw/virtio/trace-events   |  2 ++
 hw/virtio/vhost-user.c   | 30 ++++++++++++++++++++++++++++++
 migration/postcopy-ram.c |  5 +++++
 migration/postcopy-ram.h |  1 +
 4 files changed, 38 insertions(+)

diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
index e320a90941..f18b67a1f2 100644
--- a/hw/virtio/trace-events
+++ b/hw/virtio/trace-events
@@ -1,6 +1,8 @@
 # See docs/tracing.txt for syntax documentation.
 
 # hw/virtio/vhost-user.c
+vhost_user_postcopy_end_entry(void) ""
+vhost_user_postcopy_end_exit(void) ""
 vhost_user_postcopy_fault_handler(const char *name, uint64_t fault_address, 
int nregions) "%s: @%"PRIx64" nregions:%d"
 vhost_user_postcopy_fault_handler_loop(int i, uint64_t client_base, uint64_t 
size) "%d: client%"PRIx64" +%"PRIx64
 vhost_user_postcopy_fault_handler_found(int i, uint64_t region_offset, 
uint64_t rb_offset) "%d: region_offset: %"PRIx64" rb_offset:%"PRIx64
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index b29a141703..4388ce7c69 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -921,6 +921,33 @@ static int vhost_user_postcopy_listen(struct vhost_dev 
*dev, Error **errp)
     return 0;
 }
 
+/*
+ * Called at the end of postcopy
+ */
+static int vhost_user_postcopy_end(struct vhost_dev *dev, Error **errp)
+{
+    VhostUserMsg msg = {
+        .request = VHOST_USER_POSTCOPY_END,
+        .flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
+    };
+    int ret;
+
+    trace_vhost_user_postcopy_end_entry();
+    if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
+        error_setg(errp, "Failed to send postcopy_end to vhost");
+        return -1;
+    }
+
+    ret = process_message_reply(dev, &msg);
+    if (ret) {
+        error_setg(errp, "Failed to receive reply to postcopy_end");
+        return ret;
+    }
+    trace_vhost_user_postcopy_end_exit();
+
+    return 0;
+}
+
 static int vhost_user_postcopy_notifier(NotifierWithReturn *notifier,
                                         void *opaque)
 {
@@ -946,6 +973,9 @@ static int vhost_user_postcopy_notifier(NotifierWithReturn 
*notifier,
     case POSTCOPY_NOTIFY_INBOUND_LISTEN:
         return vhost_user_postcopy_listen(dev, pnd->errp);
 
+    case POSTCOPY_NOTIFY_INBOUND_END:
+        return vhost_user_postcopy_end(dev, pnd->errp);
+
     default:
         /* We ignore notifications we don't know */
         break;
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index b97fc9398b..fdd53cdf1e 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -337,7 +337,12 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState 
*mis)
 
     if (mis->have_fault_thread) {
         uint64_t tmp64;
+        Error *local_err = NULL;
 
+        if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_END, &local_err)) {
+            error_report_err(local_err);
+            return -1;
+        }
         if (qemu_ram_foreach_block(cleanup_range, mis)) {
             return -1;
         }
diff --git a/migration/postcopy-ram.h b/migration/postcopy-ram.h
index ecf731c689..d0dc838001 100644
--- a/migration/postcopy-ram.h
+++ b/migration/postcopy-ram.h
@@ -130,6 +130,7 @@ enum PostcopyNotifyReason {
     POSTCOPY_NOTIFY_PROBE = 0,
     POSTCOPY_NOTIFY_INBOUND_ADVISE,
     POSTCOPY_NOTIFY_INBOUND_LISTEN,
+    POSTCOPY_NOTIFY_INBOUND_END,
 };
 
 struct PostcopyNotifyData {
-- 
2.13.0