Re: [PATCH v3 26/29] hw/arm/virt: Plug pcihp hotplug/hotunplug callbacks

[Eric Auger <eric.auger@redhat.com>]

Hi Igor,

On 6/20/25 3:10 PM, Igor Mammedov wrote:
> On Mon, 16 Jun 2025 11:46:55 +0200
> Eric Auger <eric.auger@redhat.com> wrote:
>
>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> why do we still need this?
>
> pcihp code should override native pcie bus handlers, and then
> when device_add calls bus hotplug handlers it will be pcihp ones.
It was needed because I did not call qbus_set_hotplug_handler() as done in
ich9.c. So I think I should be able to get rid of this patch

Thanks

Eric
>
>> ---
>> v2 -> v3:
>> - fix cohabitation with virtio-mem-pci device and tested
>>   hotplug/unplug of this latter (Igor)
>> ---
>>  hw/arm/virt.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++---
>>  1 file changed, 69 insertions(+), 3 deletions(-)
>>
>> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
>> index 8c882e0794..06b87e1050 100644
>> --- a/hw/arm/virt.c
>> +++ b/hw/arm/virt.c
>> @@ -1747,6 +1747,22 @@ static void virt_build_smbios(VirtMachineState *vms)
>>      }
>>  }
>>  
>> +static AcpiPciHpState *get_acpi_pcihp_state(VirtMachineState *vms)
>> +{
>> +    AcpiGedState *acpi_ged_state;
>> +    AcpiPciHpState *pcihp_state;
>> +
>> +    if (!vms->acpi_dev) {
>> +        return NULL;
>> +    }
>> +    acpi_ged_state = ACPI_GED(vms->acpi_dev);
>> +    pcihp_state = &acpi_ged_state->pcihp_state;
>> +    if (pcihp_state->use_acpi_hotplug_bridge) {
>> +        return pcihp_state;
>> +    }
>> +    return NULL;
>> +}
>> +
>>  static
>>  void virt_machine_done(Notifier *notifier, void *data)
>>  {
>> @@ -2907,6 +2923,13 @@ static void virt_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
>>  {
>>      VirtMachineState *vms = VIRT_MACHINE(hotplug_dev);
>>  
>> +    if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
>> +        if (get_acpi_pcihp_state(vms)) {
>> +            acpi_pcihp_device_pre_plug_cb(HOTPLUG_HANDLER(vms->acpi_dev),
>> +                                          dev, errp);
>> +        }
>> +    }
>> +
>>      if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
>>          virt_memory_pre_plug(hotplug_dev, dev, errp);
>>      } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MD_PCI)) {
>> @@ -2961,6 +2984,15 @@ static void virt_machine_device_plug_cb(HotplugHandler *hotplug_dev,
>>          }
>>      }
>>  
>> +    if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
>> +        AcpiPciHpState *pcihp_state = get_acpi_pcihp_state(vms);
>> +
>> +        if (pcihp_state) {
>> +            acpi_pcihp_device_plug_cb(HOTPLUG_HANDLER(vms->acpi_dev),
>> +                                      pcihp_state, dev, errp);
>> +        }
>> +    }
>> +
>>      if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
>>          virt_memory_plug(hotplug_dev, dev, errp);
>>      } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MD_PCI)) {
>> @@ -3017,12 +3049,27 @@ out:
>>  static void virt_machine_device_unplug_request_cb(HotplugHandler *hotplug_dev,
>>                                            DeviceState *dev, Error **errp)
>>  {
>> +    bool supported = false;
>> +
>>      if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
>>          virt_dimm_unplug_request(hotplug_dev, dev, errp);
>> +        supported = true;
>>      } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MD_PCI)) {
>>          virtio_md_pci_unplug_request(VIRTIO_MD_PCI(dev), MACHINE(hotplug_dev),
>>                                       errp);
>> -    } else {
>> +        supported = true;
>> +    }
>> +    if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
>> +        VirtMachineState *vms = VIRT_MACHINE(hotplug_dev);
>> +        AcpiPciHpState *pcihp_state = get_acpi_pcihp_state(vms);
>> +
>> +        if (pcihp_state) {
>> +            acpi_pcihp_device_unplug_request_cb(HOTPLUG_HANDLER(vms->acpi_dev),
>> +                                                pcihp_state, dev, errp);
>> +            supported = true;
>> +        }
>> +    }
>> +    if (!supported) {
>>          error_setg(errp, "device unplug request for unsupported device"
>>                     " type: %s", object_get_typename(OBJECT(dev)));
>>      }
>> @@ -3031,11 +3078,27 @@ static void virt_machine_device_unplug_request_cb(HotplugHandler *hotplug_dev,
>>  static void virt_machine_device_unplug_cb(HotplugHandler *hotplug_dev,
>>                                            DeviceState *dev, Error **errp)
>>  {
>> +    bool supported = false;
>> +
>>      if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
>>          virt_dimm_unplug(hotplug_dev, dev, errp);
>> +        supported = true;
>>      } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MD_PCI)) {
>>          virtio_md_pci_unplug(VIRTIO_MD_PCI(dev), MACHINE(hotplug_dev), errp);
>> -    } else {
>> +        supported = true;
>> +    }
>> +    if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
>> +        VirtMachineState *vms = VIRT_MACHINE(hotplug_dev);
>> +
>> +        AcpiPciHpState *pcihp_state = get_acpi_pcihp_state(vms);
>> +
>> +        if (pcihp_state) {
>> +            acpi_pcihp_device_unplug_cb(HOTPLUG_HANDLER(vms->acpi_dev),
>> +                                        pcihp_state, dev, errp);
>> +            supported = true;
>> +        }
>> +    }
>> +    if (!supported) {
>>          error_setg(errp, "virt: device unplug for unsupported device"
>>                     " type: %s", object_get_typename(OBJECT(dev)));
>>      }
>> @@ -3045,11 +3108,14 @@ static HotplugHandler *virt_machine_get_hotplug_handler(MachineState *machine,
>>                                                          DeviceState *dev)
>>  {
>>      MachineClass *mc = MACHINE_GET_CLASS(machine);
>> +    VirtMachineState *vms = VIRT_MACHINE(machine);
>>  
>>      if (device_is_dynamic_sysbus(mc, dev) ||
>>          object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM) ||
>>          object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MD_PCI) ||
>> -        object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_IOMMU_PCI)) {
>> +        object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_IOMMU_PCI) ||
>> +        (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE) &&
>> +                             get_acpi_pcihp_state(vms))) {
>>          return HOTPLUG_HANDLER(machine);
>>      }
>>      return NULL;