Re: [Qemu-arm] [Qemu-devel] [PATCH RFC 10/16] hw/ppc/spapr: don't use smp_cores, smp_threads

[David Gibson]

On Tue, Jun 14, 2016 at 08:23:08AM +0200, Andrew Jones wrote:
> On Tue, Jun 14, 2016 at 01:03:41PM +1000, David Gibson wrote:
> > On Fri, Jun 10, 2016 at 07:40:21PM +0200, Andrew Jones wrote:
> > > Use CPUState nr_cores,nr_threads and MachineState
> > > cores,threads instead.
> > > 
> > > Signed-off-by: Andrew Jones <address@hidden>
> > > ---
> > >  hw/ppc/spapr.c      | 9 +++++----
> > >  hw/ppc/spapr_rtas.c | 2 +-
> > >  2 files changed, 6 insertions(+), 5 deletions(-)
> > > 
> > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> > > index 063664234106e..f78276bb4b164 100644
> > > --- a/hw/ppc/spapr.c
> > > +++ b/hw/ppc/spapr.c
> > > @@ -35,7 +35,6 @@
> > >  #include "net/net.h"
> > >  #include "sysemu/device_tree.h"
> > >  #include "sysemu/block-backend.h"
> > > -#include "sysemu/cpus.h"
> > >  #include "sysemu/kvm.h"
> > >  #include "sysemu/device_tree.h"
> > >  #include "kvm_ppc.h"
> > > @@ -603,7 +602,7 @@ static void spapr_populate_cpu_dt(CPUState *cs, void 
> > > *fdt, int offset,
> > >      uint32_t cpufreq = kvm_enabled() ? kvmppc_get_clockfreq() : 
> > > 1000000000;
> > >      uint32_t page_sizes_prop[64];
> > >      size_t page_sizes_prop_size;
> > > -    uint32_t vcpus_per_socket = smp_threads * smp_cores;
> > > +    uint32_t vcpus_per_socket = cs->nr_cores * cs->nr_threads;

This function has an 'spapr' parameter which is a subcloss of
MachineState, so you can get to the machine value from there.

> > >      uint32_t pft_size_prop[] = {0, cpu_to_be32(spapr->htab_shift)};
> > >  
> > >      /* Note: we keep CI large pages off for now because a 64K capable 
> > > guest
> > > @@ -1774,7 +1773,7 @@ static void ppc_spapr_init(MachineState *machine)
> > >      /* Set up Interrupt Controller before we create the VCPUs */
> > >      spapr->icp = xics_system_init(machine,
> > >                                    DIV_ROUND_UP(max_cpus * 
> > > kvmppc_smt_threads(),
> > > -                                               smp_threads),
> > > +                                               machine->threads),
> > >                                    XICS_IRQS, &error_fatal);
> > >  
> > >      if (smc->dr_lmb_enabled) {
> > > @@ -2268,9 +2267,11 @@ static HotplugHandler 
> > > *spapr_get_hotpug_handler(MachineState *machine,
> > >  
> > >  static unsigned spapr_cpu_index_to_socket_id(unsigned cpu_index)
> > >  {
> > > +    CPUState *cs = first_cpu;
> > > +
> > >      /* Allocate to NUMA nodes on a "socket" basis (not that concept of
> > >       * socket means much for the paravirtualized PAPR platform) */
> > > -    return cpu_index / smp_threads / smp_cores;
> > > +    return cpu_index / cs->nr_cores / cs->nr_threads;

Here you can use qdev_get_machine().  That's no more an ugly use of a
global than using first_cpu.

> > >  }
> > >  
> > >  static void spapr_machine_class_init(ObjectClass *oc, void *data)
> > > diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
> > > index 43e2c684fda8d..3fdfbb01a20dd 100644
> > > --- a/hw/ppc/spapr_rtas.c
> > > +++ b/hw/ppc/spapr_rtas.c
> > > @@ -742,7 +742,7 @@ int spapr_rtas_device_tree_setup(void *fdt, hwaddr 
> > > rtas_addr,
> > >      lrdr_capacity[1] = cpu_to_be32(max_hotplug_addr & 0xffffffff);
> > >      lrdr_capacity[2] = 0;
> > >      lrdr_capacity[3] = cpu_to_be32(SPAPR_MEMORY_BLOCK_SIZE);
> > > -    lrdr_capacity[4] = cpu_to_be32(max_cpus/smp_threads);
> > > +    lrdr_capacity[4] = cpu_to_be32(max_cpus / machine->threads);
> > >      ret = qemu_fdt_setprop(fdt, "/rtas", "ibm,lrdr-capacity", 
> > > lrdr_capacity,
> > >                       sizeof(lrdr_capacity));
> > >      if (ret < 0) {
> > 
> > I think all the places that use cs->nr_* here it actually makes more
> > sense to use the value in the machine state.
> 
> I think I used machine state whenever I (easily) could. How do I get to
> machine state from a CPU method? I will if I can, for all machines,
> and then gladly kill the CPUState->nr_cores/nr_threads.

I can't speak to all machines, but notes above on how it can be done
for spapr.

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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