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

[Cleber Rosa <crosa@redhat.com>]

wangyanan (Y) writes:

> Hi Cleber,
>
> On 2021/7/23 6:25, Cleber Rosa wrote:
>> Yanan Wang writes:
>>
>>> In the SMP configuration, we should either specify a topology
>>> parameter with a reasonable value (equal to or greater than 1)
>>> or just leave it omitted and QEMU will calculate its value.
>>> Configurations which explicitly specify the topology parameters
>>> as zero like "sockets=0" are meaningless, so disallow them.
>>>
>>> However, the commit 1e63fe685804d
>>> (machine: pass QAPI struct to mc->smp_parse) has documented that
>>> '0' has the same semantics as omitting a parameter in the qapi
>>> comment for SMPConfiguration. So this patch fixes the doc and
>>> also adds the corresponding sanity check in the smp parsers.
>>>
>>> Suggested-by: Andrew Jones <drjones@redhat.com>
>>> Signed-off-by: Yanan Wang <wangyanan55@huawei.com>
>>> ---
>>>   hw/core/machine.c | 14 ++++++++++++++
>>>   qapi/machine.json |  6 +++---
>>>   qemu-options.hx   | 12 +++++++-----
>>>   3 files changed, 24 insertions(+), 8 deletions(-)
>> Hi Yanan,
>>
>> This looks somewhat similar to this very old patch of mine:
>>
>>     https://mail.gnu.org/archive/html/qemu-devel/2020-10/msg03039.html
>>
>> I'm putting a reference here because I believe the test can be salvaged
>> and slightly adapted for this patch of yours.
>>
>> Let me know if I can help anyhow.
>>
> Thanks for this.
> I was introducing an unit test for the smp parsing in [1], in which all
> possible valid and invalid smp configs were covered, and actually the
> "parameter=0" stuff was also covered. You can have a look, and
> suggestions are welcome. I'm not sure we need two different tests
> for the same part. :)
>

Right, I only saw the other series later.  Nice work there!

- Cleber.