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

[Philippe Mathieu-Daudé]

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?