Re: [PATCH v11 11/14] machine: Make smp_parse generic enough for all arches

[Philippe Mathieu-Daudé]

On 9/28/21 12:58, Daniel P. Berrangé wrote:
> On Tue, Sep 28, 2021 at 12:57:21PM +0200, Philippe Mathieu-Daudé wrote:
>> On 9/28/21 05:57, Yanan Wang wrote:
>>> Currently the only difference between smp_parse and pc_smp_parse
>>> is the support of dies parameter and the related error reporting.
>>> With some arch compat variables like "bool dies_supported", we can
>>> make smp_parse generic enough for all arches and the PC specific
>>> one can be removed.
>>>
>>> Making smp_parse() generic enough can reduce code duplication and
>>> ease the code maintenance, and also allows extending the topology
>>> with more arch specific members (e.g., clusters) in the future.
>>>
>>> Suggested-by: Andrew Jones <drjones@redhat.com>
>>> Suggested-by: Daniel P. Berrange <berrange@redhat.com>
>>> Signed-off-by: Yanan Wang <wangyanan55@huawei.com>
>>> ---
>>>  hw/core/machine.c   | 91 +++++++++++++++++++++++++++++++++++----------
>>>  hw/i386/pc.c        | 84 +----------------------------------------
>>>  include/hw/boards.h |  9 +++++
>>>  3 files changed, 81 insertions(+), 103 deletions(-)
>>
>>> +/*
>>> + * smp_parse - Generic function used to parse the given SMP configuration
>>> + *
>>> + * Any missing parameter in "cpus/maxcpus/sockets/cores/threads" will be
>>> + * automatically computed based on the provided ones.
>>> + *
>>> + * In the calculation of omitted sockets/cores/threads: we prefer sockets
>>> + * over cores over threads before 6.2, while preferring cores over sockets
>>> + * over threads since 6.2.
>>> + *
>>> + * In the calculation of cpus/maxcpus: When both maxcpus and cpus are 
>>> omitted,
>>> + * maxcpus will be computed from the given parameters and cpus will be set
>>> + * equal to maxcpus. When only one of maxcpus and cpus is given then the
>>> + * omitted one will be set to its given counterpart's value. Both maxcpus 
>>> and
>>> + * cpus may be specified, but maxcpus must be equal to or greater than 
>>> cpus.
>>> + *
>>> + * For compatibility, apart from the parameters that will be computed, 
>>> newly
>>> + * introduced topology members which are likely to be target specific 
>>> should
>>> + * be directly set as 1 if they are omitted (e.g. dies for PC since 4.1).
>>> + */
>>>  static void smp_parse(MachineState *ms, SMPConfiguration *config, Error 
>>> **errp)
>>
>> Can we have it return a boolean instead?
> 
> That's unrelated to this change, so ought to be a separate commit if
> done.

Sure, fine by me.