On Thu, Jul 14, 2016 at 11:18:36AM +0200, Igor Mammedov wrote: > On Wed, 13 Jul 2016 20:37:13 -0300 > Eduardo Habkost <ehabk...@redhat.com> wrote: > > > On Wed, Jul 13, 2016 at 06:59:21PM -0400, Bandan Das wrote: > > > Eduardo Habkost <ehabk...@redhat.com> writes: > > > > > > > On Wed, Jul 13, 2016 at 06:32:27PM -0400, Bandan Das wrote: > > > >> Igor Mammedov <imamm...@redhat.com> writes: > > > >> > > > >> > consolidate possible_cpus array management in pc_cpu_plug() > > > >> > for smp_cpus, coldplugged with -device and hotplugged with > > > >> > device_add. > > > >> > > > >> So, this takes care of the hotplug case and 09/19 took care of the > > > >> coldplug case, right ? If yes, we should probably modify this commit > > > >> message a little. > > > > > > > > This makes pc_cpu_plug() take care of both: now it will handle > > > > the coldplug case also (in addition to the hotplug case, that it > > > > already handled). I don't understand what you mean. > > > > > > > > Are you talking about the rtc_set_memory() call, only? This seems > > > > to be the only hotplug-specific code that still remains, in this > > > > > > Right, I thought the rtc_set_memory() call in 09/19 takes care of the > > > case when the user boots with "-device" and this takes care of the case > > > when user invokes device_add, no ? > > > > Yes for rtc_set_memory(). But the main purpose of this patch is > > to reuse all the rest of pc_cpu_plug() (i.e. everything except > > for the rtc_set_memory() call) for the coldplug CPUs too. > > > > Note that I didn't review the patch completely, yet. The > > replacement for the possible_cpus code looks OK, but I didn't > > check if it is safe to call > > HOTPLUG_HANDLER_GET_CLASS(pcms->acpi_dev)->plug() for coldplugged > > CPUs too. > for cpus created at pc_cpus_init() time, that path is unreachable > since pcms->acpi_dev == NULL,
Sounds fragile, as it requires specific initialization ordering in the pc_cpus_init() caller. But: > > even if in the future that path becomes reachable > (when we could specify all CPUs including BSP with -device, it doesn't work > for BSP yet) > i.e. pcms->acpi_dev != NULL > then acpi_device will have be initialized see cpu_hotplug_hw_init() > and following plug handler will be called acpi_cpu_plug_cb() doing what > it was supposed to do. For reference for others, acpi_cpu_plug_cb() is: void acpi_cpu_plug_cb(HotplugHandler *hotplug_dev, CPUHotplugState *cpu_st, DeviceState *dev, Error **errp) { AcpiCpuStatus *cdev; cdev = get_cpu_status(cpu_st, dev); if (!cdev) { return; } cdev->cpu = CPU(dev); if (dev->hotplugged) { cdev->is_inserting = true; acpi_send_event(DEVICE(hotplug_dev), ACPI_CPU_HOTPLUG_STATUS); } } get_cpu_status() should return non-NULL for all possible CPUs. So the only code for coldplug case is cdev->cpu = CPU(dev), which is really something we want to run. So, that means it works properly on both cases: if pcms->acpi_dev==NULL and if pcms->acpi_dev != NULL. Reviewed-by: Eduardo Habkost <ehabk...@redhat.com> Related question: why does CPUHotplugState needs to duplicate the list of (CPUState *cpu, uint64_t arch_id) pairs, if PCMachineState already maintains a list with exactly the same information? > > > > > > > > > > patch. > > > > > > > >> > > > >> Bandan > > > >> > Signed-off-by: Igor Mammedov <imamm...@redhat.com> > > > >> > --- > > > >> > hw/i386/pc.c | 25 +++++++++---------------- > > > >> > 1 file changed, 9 insertions(+), 16 deletions(-) > > > >> > > > > >> > diff --git a/hw/i386/pc.c b/hw/i386/pc.c > > > >> > index 3206572..0f85b56 100644 > > > >> > --- a/hw/i386/pc.c > > > >> > +++ b/hw/i386/pc.c > > > >> > @@ -1142,7 +1142,6 @@ void pc_cpus_init(PCMachineState *pcms) > > > >> > if (i < smp_cpus) { > > > >> > cpu = pc_new_cpu(typename, > > > >> > x86_cpu_apic_id_from_index(i), > > > >> > &error_fatal); > > > >> > - pcms->possible_cpus->cpus[i].cpu = CPU(cpu); > > > >> > object_unref(OBJECT(cpu)); > > > >> > } > > > >> > } > > > >> > @@ -1697,25 +1696,19 @@ static void pc_cpu_plug(HotplugHandler > > > >> > *hotplug_dev, > > > >> > Error *local_err = NULL; > > > >> > PCMachineState *pcms = PC_MACHINE(hotplug_dev); > > > >> > > > > >> > - if (!dev->hotplugged) { > > > >> > - goto out; > > > >> > - } > > > >> > - > > > >> > - if (!pcms->acpi_dev) { > > > >> > - error_setg(&local_err, > > > >> > - "cpu hotplug is not enabled: missing acpi > > > >> > device"); > > > >> > - goto out; > > > >> > + if (pcms->acpi_dev) { > > > >> > + hhc = HOTPLUG_HANDLER_GET_CLASS(pcms->acpi_dev); > > > >> > + hhc->plug(HOTPLUG_HANDLER(pcms->acpi_dev), dev, &local_err); > > > >> > + if (local_err) { > > > >> > + goto out; > > > >> > + } > > > >> > } > > > >> > > > > >> > - hhc = HOTPLUG_HANDLER_GET_CLASS(pcms->acpi_dev); > > > >> > - hhc->plug(HOTPLUG_HANDLER(pcms->acpi_dev), dev, &local_err); > > > >> > - if (local_err) { > > > >> > - goto out; > > > >> > + if (dev->hotplugged) { > > > >> > + /* increment the number of CPUs */ > > > >> > + rtc_set_memory(pcms->rtc, 0x5f, rtc_get_memory(pcms->rtc, > > > >> > 0x5f) + 1); > > > >> > } > > > >> > > > > >> > - /* increment the number of CPUs */ > > > >> > - rtc_set_memory(pcms->rtc, 0x5f, rtc_get_memory(pcms->rtc, 0x5f) > > > >> > + 1); > > > >> > - > > > >> > found_cpu = pc_find_cpu_slot(pcms, CPU(dev), NULL); > > > >> > found_cpu->cpu = CPU(dev); > > > >> > out: > > > -- Eduardo