[Qemu-devel] [PATCH] char: Prevent multiple devices opening same chardev

[Amit Shah]

Prevent:

-chardev socket,path=/tmp/foo,server,nowait,id=c0 \
-device virtserialport,chardev=c0,id=vs0 \
-device virtserialport,chardev=c0,id=vs1

Reported-by: Mike Cao <b...@redhat.com>
Signed-off-by: Amit Shah <amit.s...@redhat.com>
---
 hw/qdev-properties.c |    7 ++++++-
 qemu-char.h          |    1 +
 2 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/hw/qdev-properties.c b/hw/qdev-properties.c
index a493087..c36b394 100644
--- a/hw/qdev-properties.c
+++ b/hw/qdev-properties.c
@@ -351,8 +351,13 @@ static int parse_chr(DeviceState *dev, Property *prop, 
const char *str)
     CharDriverState **ptr = qdev_get_prop_ptr(dev, prop);
 
     *ptr = qemu_chr_find(str);
-    if (*ptr == NULL)
+    if (*ptr == NULL) {
         return -ENOENT;
+    }
+    if ((*ptr)->assigned) {
+        return -EEXIST;
+    }
+    (*ptr)->assigned = 1;
     return 0;
 }
 
diff --git a/qemu-char.h b/qemu-char.h
index 56d9954..fb96eef 100644
--- a/qemu-char.h
+++ b/qemu-char.h
@@ -70,6 +70,7 @@ struct CharDriverState {
     char *label;
     char *filename;
     int opened;
+    int assigned; /* chardev assigned to a device */
     QTAILQ_ENTRY(CharDriverState) next;
 };
 
-- 
1.7.4