net/colo-compare.c: Fix deadlock in compare_chr_send

The chr_out chardev is connected to a filter-redirector
running in the main loop. qemu_chr_fe_write_all might block
here in compare_chr_send if the (socket-)buffer is full.
If another filter-redirector in the main loop want's to
send data to chr_pri_in it might also block if the buffer
is full. This leads to a deadlock because both event loops
get blocked.

Fix this by converting compare_chr_send to a coroutine and
putting the packets in a send queue.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Reviewed-by: Zhang Chen <chen.zhang@intel.com>
Tested-by: Zhang Chen <chen.zhang@intel.com>
Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/net/colo.c b/net/colo.c
index 8196b35..a6c66d8 100644
--- a/net/colo.c
+++ b/net/colo.c
@@ -185,6 +185,13 @@ void packet_destroy(void *opaque, void *user_data)
     g_slice_free(Packet, pkt);
 }
 
+void packet_destroy_partial(void *opaque, void *user_data)
+{
+    Packet *pkt = opaque;
+
+    g_slice_free(Packet, pkt);
+}
+
 /*
  * Clear hashtable, stop this hash growing really huge
  */