Re: [Qemu-devel] [RFC Patch 2/3] chardev: save the passed in 'fd' parameter during parsing

[Wei Xu <wexu@redhat.com>]

On 2016年06月01日 01:26, Eric Blake wrote:
> On 05/31/2016 10:30 AM, wexu@redhat.com wrote:
>> From: Wei Xu <wexu@redhat.com>
>>
>> Save the 'fd' paramter as unix socket 'sockfd' member.
>>
>> Signed-off-by: Wei Xu <wexu@redhat.com>
>> ---
>>   qemu-char.c | 7 +++++++
>>   1 file changed, 7 insertions(+)
>>
>> diff --git a/qemu-char.c b/qemu-char.c
>> index ea9c02e..8d20494 100644
>> --- a/qemu-char.c
>> +++ b/qemu-char.c
>> @@ -3664,6 +3664,7 @@ static void qemu_chr_parse_socket(QemuOpts *opts, ChardevBackend *backend,
>>       bool is_telnet      = qemu_opt_get_bool(opts, "telnet", false);
>>       bool do_nodelay     = !qemu_opt_get_bool(opts, "delay", true);
>>       int64_t reconnect   = qemu_opt_get_number(opts, "reconnect", 0);
>> +    const int32_t fd = (int32_t)qemu_opt_get_number(opts, "sockfd", 0);
>>       const char *path = qemu_opt_get(opts, "path");
>>       const char *host = qemu_opt_get(opts, "host");
>>       const char *port = qemu_opt_get(opts, "port");
>> @@ -3708,6 +3709,12 @@ static void qemu_chr_parse_socket(QemuOpts *opts, ChardevBackend *backend,
>>           addr->type = SOCKET_ADDRESS_KIND_UNIX;
>>           q_unix = addr->u.q_unix.data = g_new0(UnixSocketAddress, 1);
>>           q_unix->path = g_strdup(path);
>> +
>> +        if (fd) {
>> +            q_unix->sockfd = fd;
>> +        } else {
>> +            q_unix->sockfd = 0;
>
> 0 is a valid fd number; this risks accidentally closing stdin later on.
>   Please use -1 for unset, if you must store an fd number.  But given my
> comments on patch 1, I'm not sure that you need this addition.
Thanks for your comment, i just wonder what's the motivation of 
qemu_open(), seems it's more like an regular file consideration, is it?
can it be easily expended to socket file?
>