[RFC PATCH 2/4] net/awd.c: Initailize input/output chardev

[Zhang Chen]

From: Zhang Chen <chen.zh...@intel.com>

Find and check the chardev awd_node and notification_node,
The awd_node used for keep connect with outside(like VM client/other
host/Remote server), and the notification_node used for do some
operation when disconnect event occur.

Signed-off-by: Zhang Chen <chen.zh...@intel.com>
---
 net/awd.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/net/awd.c b/net/awd.c
index d42b4a7372..ad3d39c982 100644
--- a/net/awd.c
+++ b/net/awd.c
@@ -42,6 +42,8 @@ typedef struct AwdState {
     char *opt_script;
     uint32_t pulse_interval;
     uint32_t timeout;
+    CharBackend chr_awd_node;
+    CharBackend chr_notification_node;
     IOThread *iothread;
 } AwdState;
 
@@ -175,9 +177,30 @@ out:
     error_propagate(errp, local_err);
 }
 
+static int find_and_check_chardev(Chardev **chr,
+                                  char *chr_name,
+                                  Error **errp)
+{
+    *chr = qemu_chr_find(chr_name);
+    if (*chr == NULL) {
+        error_setg(errp, "Device '%s' not found",
+                   chr_name);
+        return 1;
+    }
+
+    if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
+        error_setg(errp, "chardev \"%s\" is not reconnectable",
+                   chr_name);
+        return 1;
+    }
+
+    return 0;
+}
+
 static void awd_complete(UserCreatable *uc, Error **errp)
 {
     AwdState *s = AWD(uc);
+    Chardev *chr;
 
     if (!s->awd_node || !s->iothread ||
         !s->notification_node || !s->opt_script) {
@@ -187,6 +210,20 @@ static void awd_complete(UserCreatable *uc, Error **errp)
         return;
     }
 
+    if (find_and_check_chardev(&chr, s->awd_node, errp) ||
+        !qemu_chr_fe_init(&s->chr_awd_node, chr, errp)) {
+        error_setg(errp, "advanced-watchdog can't find chardev awd_node: %s",
+                   s->awd_node);
+        return;
+    }
+
+    if (find_and_check_chardev(&chr, s->notification_node, errp) ||
+        !qemu_chr_fe_init(&s->chr_notification_node, chr, errp)) {
+        error_setg(errp, "advanced-watchdog can't find "
+                   "chardev notification_node: %s", s->notification_node);
+        return;
+    }
+
     return;
 }
 
-- 
2.17.1