Re: [PATCH v5 2/4] hw/arm/virt: Consider SMP configuration in CPU topology

[Gavin Shan]

Hi Yanan,

On 4/13/22 8:39 PM, wangyanan (Y) wrote:
> On 2022/4/3 22:59, Gavin Shan wrote:
> > Currently, the SMP configuration isn't considered when the CPU
> > topology is populated. In this case, it's impossible to provide
> > the default CPU-to-NUMA mapping or association based on the socket
> > ID of the given CPU.
> >
> > This takes account of SMP configuration when the CPU topology
> > is populated. The die ID for the given CPU isn't assigned since
> > it's not supported on arm/virt machine yet.
> >
> > Signed-off-by: Gavin Shan <gshan@redhat.com>
> > ---
> >   hw/arm/virt.c | 16 +++++++++++++++-
> >   1 file changed, 15 insertions(+), 1 deletion(-)
> >
> > diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> > index d2e5ecd234..3174526730 100644
> > --- a/hw/arm/virt.c
> > +++ b/hw/arm/virt.c
> > @@ -2505,6 +2505,7 @@ static const CPUArchIdList 
> > *virt_possible_cpu_arch_ids(MachineState *ms)
> >       int n;
> >       unsigned int max_cpus = ms->smp.max_cpus;
> >       VirtMachineState *vms = VIRT_MACHINE(ms);
> > +    MachineClass *mc = MACHINE_GET_CLASS(vms);
> >       if (ms->possible_cpus) {
> >           assert(ms->possible_cpus->len == max_cpus);
> > @@ -2518,8 +2519,21 @@ static const CPUArchIdList 
> > *virt_possible_cpu_arch_ids(MachineState *ms)
> >           ms->possible_cpus->cpus[n].type = ms->cpu_type;
> >           ms->possible_cpus->cpus[n].arch_id =
> >               virt_cpu_mp_affinity(vms, n);
> > +
> > +        assert(!mc->smp_props.dies_supported);
> > +        ms->possible_cpus->cpus[n].props.has_socket_id = true;
> > +        ms->possible_cpus->cpus[n].props.socket_id =
> > +            (n / (ms->smp.clusters * ms->smp.cores * ms->smp.threads)) %
> > +            ms->smp.sockets;
> No need for "% ms->smp.sockets".

Yeah, lets remove it in v6.

> > +        ms->possible_cpus->cpus[n].props.has_cluster_id = true;
> > +        ms->possible_cpus->cpus[n].props.cluster_id =
> > +            (n / (ms->smp.cores * ms->smp.threads)) % ms->smp.clusters;
> > +        ms->possible_cpus->cpus[n].props.has_core_id = true;
> > +        ms->possible_cpus->cpus[n].props.core_id =
> > +            (n / ms->smp.threads) % ms->smp.cores;
> >           ms->possible_cpus->cpus[n].props.has_thread_id = true;
> > -        ms->possible_cpus->cpus[n].props.thread_id = n;
> > +        ms->possible_cpus->cpus[n].props.thread_id =
> > +            n % ms->smp.threads;
> >       }
> >       return ms->possible_cpus;
> >   }
> Otherwise, looks good to me:
> Reviewed-by: Yanan Wang <wangyanan55@huawei.com>

Thanks for your time to review :)

Thanks,
Gavin