Re: [Qemu-devel] [ANNOUNCE] QEMU 1.5.0-rc2 is now available

[Anthony Liguori <aliguori@us.ibm.com>]

KONRAD Frédéric <fred.konrad@greensocs.com> writes:

> On 16/05/2013 16:51, Paolo Bonzini wrote:
>> Il 16/05/2013 16:21, mdroth ha scritto:
>>> commit e37da3945fa2fde161e1b217f937fc318c4b7639
>>> Author: KONRAD Frederic <fred.konrad@greensocs.com>
>>> Date:   Thu Apr 11 16:29:58 2013 +0200
>>>
>>>      virtio-net-pci: switch to the new API.
>>>      
>>>      Here the virtio-net-pci is modified for the new API. The device
>>>      virtio-net-pci extends virtio-pci. It creates and connects a
>>>      virtio-net-device during the init. The properties are not changed.
>>>      
>>>      Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
>>>      Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
>>>      Message-id: 1365690602-22729-4-git-send-email-fred.konrad@greensocs.com
>>>      Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
>>>
>>> And if we roll that back, we have similar failures for virtio-blk, and most
>>> likely the other virtio devices touched by the refactoring.
>>>
>>> The issue seems to be a change the way section id strings are generated in
>>> vmstate_register(). In v1.4.x we had:
>>>
>>> se->instance_id: 0, se->idstr: 0000:00:03.0/virtio-net
>>>
>>> In v1.5.0-rc2 we have:
>>>
>>> se->instance_id: 0, se->idstr: virtio-net
>>>
>>> This seems to be due to the fact that these devices now sit on a
>>> TYPE_VIRTIO_BUS that has no implementation of TYPE_BUS's get_dev_path()
>>> interface, which is what savevm uses to calculate the id prefix for
>>> se->idstr.
>>>
>>> Prior to the refactoring, the device sat on a TYPE_PCI_BUS which used
>>> pcibus_get_dev_path() to calculate this.
>>>
>>> I'm not sure what the best fix is for this. I looking at implementing
>>> get_dev_path() for TYPE_VIRTIO_BUS, but to maintain migration
>>> compatibility we'd end up baking in PCI-specific stuff which from what
>>> I gather is exactly what we were trying to avoid there.
>> I think get_dev_path for TYPE_VIRTIO_BUS could simply forward to the
>> parent device's parent bus.
>>
>> Paolo
>
> I think this can do the job, any better idea?

Monkey patching is a little ugly but it is a concise way of fixing the
problem.

Mike, can you confirm the patch?

Fred, can you add a Signed-off-by and send as a top-level?

Regards,

Anthony Liguori

>
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index d5257ed..e033b53 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -43,7 +43,6 @@
>   #endif
>
>   static void pcibus_dev_print(Monitor *mon, DeviceState *dev, int indent);
> -static char *pcibus_get_dev_path(DeviceState *dev);
>   static char *pcibus_get_fw_dev_path(DeviceState *dev);
>   static int pcibus_reset(BusState *qbus);
>
> @@ -2129,7 +2128,7 @@ static char *pcibus_get_fw_dev_path(DeviceState *dev)
>       return g_strdup(path);
>   }
>
> -static char *pcibus_get_dev_path(DeviceState *dev)
> +char *pcibus_get_dev_path(DeviceState *dev)
>   {
>       PCIDevice *d = container_of(dev, PCIDevice, qdev);
>       PCIDevice *t;
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index 70d2c6b..0241223 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -1514,11 +1514,19 @@ static void virtio_pci_bus_new(VirtioBusState 
> *bus, VirtIOPCIProxy *dev)
>       qbus->allow_hotplug = 1;
>   }
>
> +static char *virtio_pci_bus_get_dev_path(DeviceState *dev)
> +{
> +    BusState *bus = qdev_get_parent_bus(dev);
> +    DeviceState *proxy = DEVICE(bus->parent);
> +    return g_strdup(pcibus_get_dev_path(proxy));
> +}
> +
>   static void virtio_pci_bus_class_init(ObjectClass *klass, void *data)
>   {
>       BusClass *bus_class = BUS_CLASS(klass);
>       VirtioBusClass *k = VIRTIO_BUS_CLASS(klass);
>       bus_class->max_dev = 1;
> +    bus_class->get_dev_path = virtio_pci_bus_get_dev_path;
>       k->notify = virtio_pci_notify;
>       k->save_config = virtio_pci_save_config;
>       k->load_config = virtio_pci_load_config;
> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
> index 8d075ab..fb5723c 100644
> --- a/include/hw/pci/pci.h
> +++ b/include/hw/pci/pci.h
> @@ -708,6 +708,8 @@ static inline void pci_dma_sglist_init(QEMUSGList 
> *qsg, PCIDevice *dev,
>
>   extern const VMStateDescription vmstate_pci_device;
>
> +char *pcibus_get_dev_path(DeviceState *dev);
> +
>   #define VMSTATE_PCI_DEVICE(_field, _state) {                         \
>       .name       = (stringify(_field)),                               \
>       .size       = sizeof(PCIDevice),                                 \
> -- 
> 1.7.11.7