Re: [Qemu-devel] [PATCH V2] vl.c: fixed regression in machine error message

[Marcel Apfelbaum <marcel@redhat.com>]

On 02/08/2016 01:02 PM, Laszlo Ersek wrote:
> On 02/08/16 11:46, Marcel Apfelbaum wrote:
>> On 02/08/2016 12:28 PM, Laszlo Ersek wrote:
>>> On 02/08/16 11:09, Marcel Apfelbaum wrote:
>>>> Commit e1ce0c3cb(vl.c: fix regression when reading machine type from
>>>> config file)
>>>> fixed the error message when the machine type was supplied inside the
>>>> config file. However now the option name is not displayed correctly if
>>>> the error happens when the machine is specified at command line.
>>>>
>>>> Running
>>>>       ./x86_64-softmmu/qemu-system-x86_64 -M q35-1.5 -redir tcp:8022::22
>>>> will result in the error message:
>>>>       qemu-system-x86_64: -redir tcp:8022::22: unsupported machine type
>>>>       Use -machine help to list supported machines
>>>>
>>>> Fixed it by saving the error location and also extracted the code
>>>> dealing with machine options into a separate function.
>>>>
>>>> v1 -> v2:
>>>>    - Addressed Laszlo Ersek's comments:
>>>>      - no need to save the machine options location, is saved in opts
>>>>      - rename the extracted method to set_machine_options
>>>>      - added the bug reporter to the CC
>>>>
>>>>    - tested with and without the config file and the error message is
>>>> no OK:
>>>
>>> --> "is *now* OK". The typo ("no OK") should be please fixed up by the
>>> maintainer (unless another round is necessary).
>>
>> Oh, v1->v2 section should be under -- line, I'll resend
>>
>>>
>>>>    config file:
>>>>       - qemu-system-x86_64:machine-bug.conf:3: unsupported machine type
>>>>    cli:
>>>>      - qemu-system-x86_64: -M q35-1.5: unsupported machine type
>>>>
>>>> Reported-by: Michael S. Tsirkin <mst@redhat.com>
>>>> Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
>>>> ---
>>>>    vl.c | 38 +++++++++++++++++++++++++++-----------
>>>>    1 file changed, 27 insertions(+), 11 deletions(-)
>>>>
>>>> diff --git a/vl.c b/vl.c
>>>> index f043009..dd29807 100644
>>>> --- a/vl.c
>>>> +++ b/vl.c
>>>> @@ -2751,6 +2751,32 @@ static const QEMUOption *lookup_opt(int argc,
>>>> char **argv,
>>>>        return popt;
>>>>    }
>>>>
>>>> +static void set_machine_options(MachineClass **machine_class)
>>>> +{
>>>> +    const char *optarg;
>>>> +    QemuOpts *opts;
>>>> +    Location loc;
>>>> +
>>>> +    loc_push_none(&loc);
>>>> +
>>>> +    opts = qemu_get_machine_opts();
>>>> +    loc_push_none(&loc);
>>>> +    qemu_opts_loc_restore(opts);
>>>> +
>>>> +    optarg = qemu_opt_get(qemu_get_machine_opts(), "type");
>>>
>>> Not particularly important, but you could just pass "opts" as first arg
>>> here, rather than calling qemu_get_machine_opts() again. For style
>>> reasons, can you clean it up?
>>
>> I would have nothing against it, but how can we be sure that opts poins
>> to machine opts
>> at the time set_machine_options is called? Or I am missing something.
>
> Please search this new function in your text editor for occurrences of
> "qemu_get_machine_opts", and you will see. :)

Ooops... I was thinking you wanted me to pass "opts" as parameter to set_machine_options.
Anyway, it wasn't for nothing, I saw that machine_opts is assigned twice, I'll send a patch shortly :)

Finally got it, thanks
Marcel


> Thanksargument
> Laszlo
>
>>
>>>
>>> With that:
>>>
>>> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
>>
>> Thanks! Waiting for your comment to the above and I'll post again.
>> Marcel
>>
>>>
>>> Thanks
>>> Laszlo
>>>
>>>> +    if (optarg) {
>>>> +        *machine_class = machine_parse(optarg);
>>>> +    }
>>>> +
>>>> +    if (*machine_class == NULL) {
>>>> +        error_report("No machine specified, and there is no default");
>>>> +        error_printf("Use -machine help to list supported machines\n");
>>>> +        exit(1);
>>>> +    }
>>>> +
>>>> +    loc_pop(&loc);
>>>> +}
>>>> +
>>>>    static int machine_set_property(void *opaque,
>>>>                                    const char *name, const char *value,
>>>>                                    Error **errp)
>>>> @@ -4019,17 +4045,7 @@ int main(int argc, char **argv, char **envp)
>>>>
>>>>        replay_configure(icount_opts);
>>>>
>>>> -    opts = qemu_get_machine_opts();
>>>> -    optarg = qemu_opt_get(opts, "type");
>>>> -    if (optarg) {
>>>> -        machine_class = machine_parse(optarg);
>>>> -    }
>>>> -
>>>> -    if (machine_class == NULL) {
>>>> -        error_report("No machine specified, and there is no default");
>>>> -        error_printf("Use -machine help to list supported machines\n");
>>>> -        exit(1);
>>>> -    }
>>>> +    set_machine_options(&machine_class);
>>>>
>>>>        set_memory_options(&ram_slots, &maxram_size, machine_class);
>>>>
>>>>
>>>
>>
>