Re: [Qemu-devel] [PATCH] `qdev_free` when unplug a pci device

[Isaku Yamahata]

On Tue, Feb 22, 2011 at 06:36:20PM +0100, William Dauchy wrote:
>  `qdev_free` when unplug a pci device
>  It resolves a bug when detaching/attaching a network device
> 
>  # virsh detach-interface dom0 network --mac 52:54:00:f6:84:ba
>  Interface detached successfully
> 
>  # virsh attach-interface dom0 network default --mac 52:54:00:f6:84:ba
>  error: Failed to attach interface
>  error: internal error unable to execute QEMU command 'device_add': Duplicate 
> ID 'net0' for device
> 
> A detached pci device was not freed of the list `qemu_device_opts`
> ---
>  hw/pci.c |    5 ++++-
>  1 files changed, 4 insertions(+), 1 deletions(-)
> 
> diff --git a/hw/pci.c b/hw/pci.c
> index 8b76cea..1e9a8f0 100644
> --- a/hw/pci.c
> +++ b/hw/pci.c
> @@ -1671,13 +1671,16 @@ static int pci_unplug_device(DeviceState *qdev)
>  {
>      PCIDevice *dev = DO_UPCAST(PCIDevice, qdev, qdev);
>      PCIDeviceInfo *info = container_of(qdev->info, PCIDeviceInfo, qdev);
> +    int unplug;
>  
>      if (info->no_hotplug) {
>          qerror_report(QERR_DEVICE_NO_HOTPLUG, info->qdev.name);
>          return -1;
>      }
> -    return dev->bus->hotplug(dev->bus->hotplug_qdev, dev,
> +    unplug = dev->bus->hotplug(dev->bus->hotplug_qdev, dev,
>                               PCI_HOTPLUG_DISABLED);
> +    qdev_free(qdev);

Good catch.
qdev_free() should be called only when unplug had succeeded.
Although piix4 unplug always successes, pcie unplug may fail.

> +    return unplug;
>  }
>  
>  void pci_qdev_register(PCIDeviceInfo *info)
> -- 
> William
> 
> 

-- 
yamahata