Re: [Qemu-devel] [RFC PATCH v0 10/15] ppc: Factor out CPU initialization code to a new routine

[Bharata B Rao <bharata@linux.vnet.ibm.com>]

On Fri, Sep 26, 2014 at 05:29:02PM +0200, Igor Mammedov wrote:
> On Thu,  4 Sep 2014 11:36:20 +0530
> Bharata B Rao <bharata@linux.vnet.ibm.com> wrote:
> 
> > Separate out CPU initialization code into a new routine ppc_new_cpu()
> > so that it can be used from CPU hotplug path too.
> > 
> > Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
> > ---
> >  hw/ppc/spapr.c | 73 +++++++++++++++++++++++++++++++++-------------------------
> >  1 file changed, 42 insertions(+), 31 deletions(-)
> > 
> > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> > index b2ca527..41207ae 100644
> > --- a/hw/ppc/spapr.c
> > +++ b/hw/ppc/spapr.c
> > @@ -1603,6 +1603,45 @@ static SaveVMHandlers savevm_htab_handlers = {
> >      .load_state = htab_load,
> >  };
> >  
> looking at following code from POV of using CPU with device_add cmd.
> 
> > +static const char *current_cpu_model;
> do PPC CPUs use full 'model-name,feature1,-feature2' format or only
> model-name from cpu_model string?

I think it is just the model-name.

> 
> > +static PowerPCCPU *ppc_new_cpu(const char *cpu_model)
> > +{
> > +    PowerPCCPU *cpu;
> > +    CPUPPCState *env;
> > +
> > +    cpu = cpu_ppc_init(cpu_model);
> > +    if (cpu == NULL) {
> > +        fprintf(stderr, "Unable to find PowerPC CPU definition\n");
> > +        exit(1);
> > +    }
> 
> -- cut --
> > +    env = &cpu->env;
> > +
> > +    /* Set time-base frequency to 512 MHz */
> > +    cpu_ppc_tb_init(env, TIMEBASE_FREQ);
> > +
> > +    /* PAPR always has exception vectors in RAM not ROM. To ensure this,
> > +     * MSR[IP] should never be set.
> > +     */
> > +    env->msr_mask &= ~(1 << 6);
> > +
> > +    /* Tell KVM that we're in PAPR mode */
> > +    if (kvm_enabled()) {
> > +        kvmppc_set_papr(cpu);
> > +    }
> > +
> > +    if (cpu->max_compat) {
> > +        if (ppc_set_compat(cpu, cpu->max_compat) < 0) {
> > +            exit(1);
> > +        }
> > +    }
> -- cut --
> selected block looks like setting CPU internals, which could be done
> inside of CPU's realizefn.
> 
> > +
> > +    xics_cpu_setup(spapr->icp, cpu);
> 
> 
> > +    qemu_register_reset(spapr_cpu_reset, cpu);
> also could be put inside of CPU's realizefn, like it's done in
> for x86 CPU.

Right, I just converted my CPU hotplug patchset for PowerPC to use the
hotplug handler APIs and now working on to see if I can switch over to
device_add and support device_del for CPU hotplug on PowerPC.

Regards,
Bharata.