Re: [RFC 4/8] hw/core: Add cache topology options in -smp

[Zhao Liu]

Hi JeeHeng,

> > diff --git a/hw/core/machine.c b/hw/core/machine.c
> > index 426f71770a84..cb5173927b0d 100644
> > --- a/hw/core/machine.c
> > +++ b/hw/core/machine.c
> > @@ -886,6 +886,10 @@ static void machine_get_smp(Object *obj, Visitor *v, 
> > const char *name,
> >          .has_cores = true, .cores = ms->smp.cores,
> >          .has_threads = true, .threads = ms->smp.threads,
> >          .has_maxcpus = true, .maxcpus = ms->smp.max_cpus,
> > +        .l1d_cache = g_strdup(cpu_topo_to_string(ms->smp_cache.l1d)),
> > +        .l1i_cache = g_strdup(cpu_topo_to_string(ms->smp_cache.l1i)),
> > +        .l2_cache = g_strdup(cpu_topo_to_string(ms->smp_cache.l2)),
> > +        .l3_cache = g_strdup(cpu_topo_to_string(ms->smp_cache.l3)),
>
> Let's standardize the code by adding the 'has_' prefix.

SMPConfiguration is automatically generated in the compilation, and its
prototype is defined in qapi/machine.json like the following code:


> > diff --git a/qapi/machine.json b/qapi/machine.json
> > index d0e7f1f615f3..0a923ac38803 100644
> > --- a/qapi/machine.json
> > +++ b/qapi/machine.json
> > @@ -1650,6 +1650,14 @@
> >  #
> >  # @threads: number of threads per core
> >  #
> > +# @l1d-cache: topology hierarchy of L1 data cache (since 9.0)
> > +#
> > +# @l1i-cache: topology hierarchy of L1 instruction cache (since 9.0)
> > +#
> > +# @l2-cache: topology hierarchy of L2 unified cache (since 9.0)
> > +#
> > +# @l3-cache: topology hierarchy of L3 unified cache (since 9.0)
> > +#
> >  # Since: 6.1
> >  ##
> >  { 'struct': 'SMPConfiguration', 'data': {
> > @@ -1662,7 +1670,11 @@
> >       '*modules': 'int',
> >       '*cores': 'int',
> >       '*threads': 'int',
> > -     '*maxcpus': 'int' } }
> > +     '*maxcpus': 'int',
> > +     '*l1d-cache': 'str',
> > +     '*l1i-cache': 'str',
> > +     '*l2-cache': 'str',
> > +     '*l3-cache': 'str' } }
> >

The gnerated complete structure is (will in build/qapi/qapi-types-machine.h):

struct SMPConfiguration {
    bool has_cpus;
    int64_t cpus;
    bool has_drawers;
    int64_t drawers;
    bool has_books;
    int64_t books;
    bool has_sockets;
    int64_t sockets;
    bool has_dies;
    int64_t dies;
    bool has_clusters;
    int64_t clusters;
    bool has_modules;
    int64_t modules;
    bool has_cores;
    int64_t cores;
    bool has_threads;
    int64_t threads;
    bool has_maxcpus;
    int64_t maxcpus;
    char *l1d_cache;
    char *l1i_cache;
    char *l2_cache;
    char *l3_cache;
};

The int member defined in qapi/machine.json will get their corresponding
status fields as has_* to indicate if user sets those int fields.

For str type, the status field is not needed since NULL is enough to
indicate no user sets that.

Thanks,
Zhao