Re: [Qemu-devel] [PATCH v3 04/10] hw/arm/virt: Add memory hotplug framework

[Shameerali Kolothum Thodi]

> -----Original Message-----
> From: Auger Eric [mailto:address@hidden
> Sent: 28 March 2019 15:38
> To: Shameerali Kolothum Thodi <address@hidden>;
> address@hidden; address@hidden; address@hidden;
> address@hidden; address@hidden;
> address@hidden; address@hidden
> Cc: Linuxarm <address@hidden>; xuwei (O) <address@hidden>
> Subject: Re: [PATCH v3 04/10] hw/arm/virt: Add memory hotplug framework
> 
> Hi Shameer,
> 
> On 3/21/19 11:47 AM, Shameer Kolothum wrote:
> > From: Eric Auger <address@hidden>
> >
> > This patch adds the the memory hot-plug/hot-unplug infrastructure
> s/the the/the (sorry my fault)
> > in machvirt. It is still not enabled as device memory is not yet
> > reported to guest.
> s/ reported to guest / exposed to the guest either through DT or ACPI.
> Note even cold-plug would not work yet.

Ok. 

> >
> > Signed-off-by: Eric Auger <address@hidden>
> > Signed-off-by: Kwangwoo Lee <address@hidden>
> > Signed-off-by: Shameer Kolothum <address@hidden>
> > ---
> >  default-configs/arm-softmmu.mak |  3 +++
> >  hw/arm/virt.c                   | 53
> ++++++++++++++++++++++++++++++++++++++++-
> >  2 files changed, 55 insertions(+), 1 deletion(-)
> >
> > diff --git a/default-configs/arm-softmmu.mak
> b/default-configs/arm-softmmu.mak
> > index 2a7efc1..795cb89 100644
> > --- a/default-configs/arm-softmmu.mak
> > +++ b/default-configs/arm-softmmu.mak
> > @@ -159,3 +159,6 @@ CONFIG_MUSICPAL=y
> >
> >  # for realview and versatilepb
> >  CONFIG_LSI_SCSI_PCI=y
> > +
> > +CONFIG_MEM_DEVICE=y
> > +CONFIG_DIMM=y
> > diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> > index ce2664a..d0ff20d 100644
> > --- a/hw/arm/virt.c
> > +++ b/hw/arm/virt.c
> > @@ -61,6 +61,8 @@
> >  #include "hw/arm/smmuv3.h"
> >  #include "hw/acpi/acpi.h"
> >  #include "target/arm/internals.h"
> > +#include "hw/mem/pc-dimm.h"
> > +#include "hw/mem/nvdimm.h"
> >
> >  #define DEFINE_VIRT_MACHINE_LATEST(major, minor, latest) \
> >      static void virt_##major##_##minor##_class_init(ObjectClass *oc, \
> > @@ -1806,6 +1808,42 @@ static const CPUArchIdList
> *virt_possible_cpu_arch_ids(MachineState *ms)
> >      return ms->possible_cpus;
> >  }
> >
> > +static void virt_memory_pre_plug(HotplugHandler *hotplug_dev,
> DeviceState *dev,
> > +                                 Error **errp)
> > +{
> > +    const bool is_nvdimm = object_dynamic_cast(OBJECT(dev),
> TYPE_NVDIMM);
> > +
> > +    if (dev->hotplugged) {
> > +        error_setg(errp, "memory hotplug is not supported");
> > +    }
> > +
> > +    if (is_nvdimm) {
> > +        error_setg(errp, "nvdimm is not yet supported");
> > +        return;
> > +    }
> Maybe this patch should be moved at the end since from this patch
> onwards, it becomes possible to instantiate a DIMM slot (with cold-plug
> qemu command line) that won't work properly. Of we simply disable
> cold-plug for PCDIMM as well at the moment?

Ok. I will check this and change accordingly.

Thanks,
Shameer

> Thanks
> 
> Eric
> > +
> > +    pc_dimm_pre_plug(PC_DIMM(dev), MACHINE(hotplug_dev), NULL,
> errp);
> > +}
> > +
> > +static void virt_memory_plug(HotplugHandler *hotplug_dev,
> > +                             DeviceState *dev, Error **errp)
> > +{
> > +    VirtMachineState *vms = VIRT_MACHINE(hotplug_dev);
> > +    Error *local_err = NULL;
> > +
> > +    pc_dimm_plug(PC_DIMM(dev), MACHINE(vms), &local_err);
> > +
> > +    error_propagate(errp, local_err);
> > +}
> > +
> > +static void virt_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
> > +                                            DeviceState *dev,
> Error **errp)
> > +{
> > +    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> > +        virt_memory_pre_plug(hotplug_dev, dev, errp);
> > +    }
> > +}
> > +
> >  static void virt_machine_device_plug_cb(HotplugHandler *hotplug_dev,
> >                                          DeviceState *dev, Error
> **errp)
> >  {
> > @@ -1817,12 +1855,23 @@ static void
> virt_machine_device_plug_cb(HotplugHandler *hotplug_dev,
> >                                       SYS_BUS_DEVICE(dev));
> >          }
> >      }
> > +    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> > +        virt_memory_plug(hotplug_dev, dev, errp);
> > +    }
> > +}
> > +
> > +static void virt_machine_device_unplug_request_cb(HotplugHandler
> *hotplug_dev,
> > +                                          DeviceState *dev, Error
> **errp)
> > +{
> > +    error_setg(errp, "device unplug request for unsupported device"
> > +               " type: %s", object_get_typename(OBJECT(dev)));
> >  }
> >
> >  static HotplugHandler *virt_machine_get_hotplug_handler(MachineState
> *machine,
> >
> DeviceState *dev)
> >  {
> > -    if (object_dynamic_cast(OBJECT(dev), TYPE_SYS_BUS_DEVICE)) {
> > +    if (object_dynamic_cast(OBJECT(dev), TYPE_SYS_BUS_DEVICE) ||
> > +       (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM))) {
> >          return HOTPLUG_HANDLER(machine);
> >      }
> >
> > @@ -1886,7 +1935,9 @@ static void virt_machine_class_init(ObjectClass
> *oc, void *data)
> >      mc->kvm_type = virt_kvm_type;
> >      assert(!mc->get_hotplug_handler);
> >      mc->get_hotplug_handler = virt_machine_get_hotplug_handler;
> > +    hc->pre_plug = virt_machine_device_pre_plug_cb;
> >      hc->plug = virt_machine_device_plug_cb;
> > +    hc->unplug_request = virt_machine_device_unplug_request_cb;
> >  }
> >
> >  static void virt_instance_init(Object *obj)
> >