Re: [Qemu-devel] [PATCH] vl.c: fix -usb option assertion failure in qemu_opt_get_bool_helper()

["Chen, Tiejun" <tiejun.chen@intel.com>]

On 2015/1/6 14:20, Shannon Zhao wrote:
> On 2015/1/6 10:37, Chen, Tiejun wrote:
>> On 2015/1/5 20:14, Marcel Apfelbaum wrote:
>>> On 01/05/2015 01:50 PM, Stefan Hajnoczi wrote:
>>>> On Mon, Jan 5, 2015 at 11:37 AM, Jan Kiszka <jan.kiszka@siemens.com>
>>>> wrote:
>>>>> On 2015-01-05 12:22, Stefan Hajnoczi wrote:
>>>>>> Commit 49d2e648e8087d154d8bf8b91f27c8e05e79d5a6 ("machine: remove
>>>>>> qemu_machine_opts global list") removed option descriptions from the
>>>>>> -machine QemuOptsList to avoid repeating MachineState's QOM properties.
>>>>>>
>>>>>> This change broke vl.c:usb_enabled() because qemu_opt_get_bool() cannot
>>>>>> be used on QemuOptsList without option descriptions since QemuOpts
>>>>>> doesn't know the type and therefore left an unparsed string value.
>>>>>>
>>>>>> This patch avoids calling qemu_opt_get_bool() to fix the assertion
>>>>>> failure:
>>>>>>
>>>>>>     $ qemu-system-x86_64 -usb
>>>>>>     qemu_opt_get_bool_helper: Assertion `opt->desc && opt->desc->type
>>>>>> == QEMU_OPT_BOOL' failed.
>>>>>>
>>>>>> Test the presence of -usb using qemu_opt_find() but use the
>>>>>> MachineState->usb field instead of qemu_opt_get_bool().
>>>>>>
>>>>>> Cc: Marcel Apfelbaum <marcel.a@redhat.com>
>>>>>> Cc: Tiejun Chen <tiejun.chen@intel.com>
>>>>>> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
>>>>>> ---
>>>>>>    vl.c | 7 +++++--
>>>>>>    1 file changed, 5 insertions(+), 2 deletions(-)
>>>>>>
>>>>>> diff --git a/vl.c b/vl.c
>>>>>> index bea9656..6e8889c 100644
>>>>>> --- a/vl.c
>>>>>> +++ b/vl.c
>>>>>> @@ -999,8 +999,11 @@ static int parse_name(QemuOpts *opts, void
>>>>>> *opaque)
>>>>>>
>>>>>>    bool usb_enabled(bool default_usb)
>>>>>>    {
>>>>>> -    return qemu_opt_get_bool(qemu_get_machine_opts(), "usb",
>>>>>> -                             has_defaults && default_usb);
>>>>>> +    if (qemu_opt_find(qemu_get_machine_opts(), "usb")) {
>>>>>> +        return current_machine->usb;
>>>>>> +    } else {
>>>>>> +        return has_defaults && default_usb;
>>>>>> +    }
>>>>>>    }
>>>>>>
>>>>>>    #ifndef _WIN32
>>>>>>
>>>>>
>>>>> That still leaves the other boolean machine options broken. A generic
>>>>> fix would be good. Or revert the original commit until we have one.
>>>>
>>>> I think we should revert the original commit.
>>>>
>>>> qemu_option_get_*() callers need to be converted to query MachineState
>>>> fields instead of using QemuOpts functions.
>>
>> Can this work out currently?
>>
> Hi Tiejun,
>
> I apply your following patch and it works. At least it doesn't crash.
>

Thanks for your test.

Tiejun

> Thanks,
> Shannon
>
>> ---
>>   util/qemu-option.c | 10 +++++-----
>>   1 file changed, 5 insertions(+), 5 deletions(-)
>>
>> diff --git a/util/qemu-option.c b/util/qemu-option.c
>> index a708241..933b885 100644
>> --- a/util/qemu-option.c
>> +++ b/util/qemu-option.c
>> @@ -317,7 +317,7 @@ const char *qemu_opt_get(QemuOpts *opts, const char *name)
>>       }
>>
>>       opt = qemu_opt_find(opts, name);
>> -    if (!opt) {
>> +    if (!opt || !opt->desc)  {
>>           const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
>>           if (desc && desc->def_value_str) {
>>               return desc->def_value_str;
>> @@ -341,7 +341,7 @@ char *qemu_opt_get_del(QemuOpts *opts, const char *name)
>>       }
>>
>>       opt = qemu_opt_find(opts, name);
>> -    if (!opt) {
>> +    if (!opt || !opt->desc)  {
>>           desc = find_desc_by_name(opts->list->desc, name);
>>           if (desc && desc->def_value_str) {
>>               str = g_strdup(desc->def_value_str);
>> @@ -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 || !opt->desc)  {
>>           const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
>>           if (desc && desc->def_value_str) {
>>               parse_option_bool(name, desc->def_value_str, &ret, &error_abort);
>> @@ -413,7 +413,7 @@ static uint64_t qemu_opt_get_number_helper(QemuOpts *opts, const char *name,
>>       }
>>
>>       opt = qemu_opt_find(opts, name);
>> -    if (opt == NULL) {
>> +    if (!opt || !opt->desc)  {
>>           const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
>>           if (desc && desc->def_value_str) {
>>               parse_option_number(name, desc->def_value_str, &ret, &error_abort);
>> @@ -450,7 +450,7 @@ static uint64_t qemu_opt_get_size_helper(QemuOpts *opts, const char *name,
>>       }
>>
>>       opt = qemu_opt_find(opts, name);
>> -    if (opt == NULL) {
>> +    if (!opt || !opt->desc)  {
>>           const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
>>           if (desc && desc->def_value_str) {
>>               parse_option_size(name, desc->def_value_str, &ret, &error_abort);
>
>
>
>