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

[Marcel Apfelbaum <marcel.apfelbaum@gmail.com>]

On 01/06/2015 11:01 AM, Chen, Tiejun wrote:
> 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.
Hi,
I just posted a fix on the mailing list.
https://www.mail-archive.com/qemu-devel@nongnu.org/msg272607.html

Please check if it works for you,
Thanks,
Marcel

>
> 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);
>>
>>
>>
>>
>