Re: [Qemu-devel] [RFC][PATCH] qemu_opt_get_bool_helper: back finding desc by name just if !opt->desc

[Marcel Apfelbaum <marcel@redhat.com>]

On 01/06/2015 04:56 PM, Stefan Hajnoczi wrote:
> On Tue, Jan 06, 2015 at 10:39:13AM +0800, Chen, Tiejun wrote:
>> On 2015/1/6 9:21, Chen, Tiejun wrote:
>>> On 2015/1/6 1:13, Eric Blake wrote:
>>>> On 01/04/2015 10:35 PM, Tiejun Chen wrote:
>>>>> After one commit 49d2e648e808, "machine: remove qemu_machine_opts
>>>>> global list", is introduced, QEMU doesn't keep a global list of
>>>>> options but set desc lately. Then we can see the following,
>>>>>
>>>>> $ x86_64-softmmu/qemu-system-x86_64 -usb
>>>>> qemu-system-x86_64: util/qemu-option.c:387: qemu_opt_get_bool_helper: \
>>>>>      Assertion `opt->desc && opt->desc->type == QEMU_OPT_BOOL' failed.
>>>>> Aborted (core dumped)
>>>>>
>>>>> So inside qemu_opt_get_bool_helper, we need to call find_desc_by_name()
>>>>> to work parse_option_bool() out just in case of !opt->desc.
>>>>>
>>>>> Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
>>>>> ---
>>>>>   util/qemu-option.c | 2 +-
>>>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/util/qemu-option.c b/util/qemu-option.c
>>>>> index a708241..7cb3601 100644
>>>>> --- a/util/qemu-option.c
>>>>> +++ b/util/qemu-option.c
>>>>> @@ -377,7 +377,7 @@ static bool qemu_opt_get_bool_helper(QemuOpts
>>>>> *opts, const char *name,
>>>>>       }
>>>>>
>>>>>       opt = qemu_opt_find(opts, name);
>>>>> -    if (opt == NULL) {
>>>>> +    if ((opt == NULL) || !opt->desc)  {
>>>>
>>>> Over-parenthesized, and looks like you also introduced a spurious space.
>>>>   Simpler to just have:
>>>>
>>>> if (!opt || !opt->desc) {
>>>
>>> Looks good.
>>>
>>>>
>>>> Also, there are other threads about the same topic.
>>>> https://lists.gnu.org/archive/html/qemu-devel/2015-01/msg00130.html
>>>
>>> Yeah, I already notice that.
>>>
>>
>> Then I realize I need to extend this to all qemu_opt_get_*.
>
> Marcel is working on a fix.
I just posted a fix on the mailing list.
https://www.mail-archive.com/qemu-devel@nongnu.org/msg272607.html

Thanks,
Marcel

>
> I think hacking qemu_opt_get_* is not a clean solution.  The intention
> was to move away from QemuOpts to QOM properties.  The patch that
> removed -machine QemuOptsList descriptions was buggy, but the proper fix
> is to make that approach work instead of hacking qemu_opt_get_*.
>
> Stefan
>