Re: [PATCH for-6.1 v2] machine: Disallow specifying topology parameters as zero

[Cornelia Huck]

On Fri, Jul 23 2021, "wangyanan (Y)" <wangyanan55@huawei.com> wrote:

> On 2021/7/23 16:02, Markus Armbruster wrote:
>> Daniel P. Berrangé <berrange@redhat.com> writes:
>>
>>> On Thu, Jul 22, 2021 at 11:43:26PM +0800, Yanan Wang wrote:
>>>> +    /*
>>>> +     * The topology parameters must be specified equal to or great than 
>>>> one
>>>> +     * or just omitted, explicit configuration like "cpus=0" is not 
>>>> allowed.
>>>> +     */
>>>> +    if ((config->has_cpus && config->cpus == 0) ||
>>>> +        (config->has_sockets && config->sockets == 0) ||
>>>> +        (config->has_dies && config->dies == 0) ||
>>>> +        (config->has_cores && config->cores == 0) ||
>>>> +        (config->has_threads && config->threads == 0) ||
>>>> +        (config->has_maxcpus && config->maxcpus == 0)) {
>>>> +        error_setg(errp, "parameters must be equal to or greater than one 
>>>> if provided");
>>> I'd suggest a slight tweak since when seen it lacks context:
>>>
>>> $ ./qemu-system-x86_64 -smp 4,cores=0,sockets=2
>>> qemu-system-x86_64: parameters must be equal to or greater than one if 
>>> provided
>>>
>>>
>>>      error_setg(errp, "CPU topology parameters must be equal to or greater 
>>> than one if provided");
>> Let's scratch "if provided".
>>
>> I'd replace "must be equal to or greater than one" by "must be
>> positive", or maybe "must be greater than zero".
> How about we use "must be greater than zero" ?
> After a grep search of these two sentences in QEMU, they both show up
> in several places. "must be positive" always reports an invalid value that
> is "< 0". While the check in this patch actually reject an invalid zero 
> value.

Of the two, I'd prefer "greater than zero".