[Qemu-devel] [PATCH] char: restore read callback on a reattached (hotplug) chardev

[Gal Hammer <ghammer@redhat.com>]

Fix a bug that was introduced in commit 386a5a1e. A removal of a device
set the chr handlers to NULL. However when the device is plugged back,
its read callback is not restored so data can't be transfter from the
host to the guest via the virtio-serial port.

https://bugzilla.redhat.com/show_bug.cgi?id=1027181

Signed-off-by: Gal Hammer <ghammer@redhat.com>
---
 qemu-char.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/qemu-char.c b/qemu-char.c
index e00f84c..44499e4 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -2510,6 +2510,16 @@ static void tcp_chr_connect(void *opaque)
     qemu_chr_be_generic_open(chr);
 }
 
+static void tcp_chr_update_read_handler(CharDriverState *chr)
+{
+    TCPCharDriver *s = chr->opaque;
+
+    if (s->chan && !chr->avail_connections) {
+        chr->fd_in_tag = io_add_watch_poll(s->chan, tcp_chr_read_poll,
+                                           tcp_chr_read, chr);
+    }
+}
+
 #define IACSET(x,a,b,c) x[0] = a; x[1] = b; x[2] = c;
 static void tcp_chr_telnet_init(int fd)
 {
@@ -2665,6 +2675,7 @@ static CharDriverState *qemu_chr_open_socket_fd(int fd, bool do_nodelay,
     chr->get_msgfd = tcp_get_msgfd;
     chr->chr_add_client = tcp_chr_add_client;
     chr->chr_add_watch = tcp_chr_add_watch;
+    chr->chr_update_read_handler = tcp_chr_update_read_handler;
     /* be isn't opened until we get a connection */
     chr->explicit_be_open = true;
 
-- 
1.8.1.4