Re: [Qemu-devel] [PATCH v10 07/10] pci: introduce function validation check during hotplug

["Michael S. Tsirkin" <mst@redhat.com>]

On Sun, Nov 27, 2016 at 07:32:30PM +0800, Cao jin wrote:
> From: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
> 
> PCI hotplug requires that function 0 is added last to close the
> slot.  Since vfio-pci supporting AER, we require that the VM bus
> contains the same set of devices as the host bus to support AER,
> we can perform an AER validation test whenever the function 0 is
> hot-added into VM.
> 
> Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
> Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
> Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>

I'm fine with this interface.

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>



> ---
>  hw/pci/pci.c         | 29 +++++++++++++++++++++++++++++
>  include/hw/pci/pci.h |  1 +
>  2 files changed, 30 insertions(+)
> 
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index 24fae16..26eaf4c 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -1942,6 +1942,20 @@ PCIDevice *pci_find_device(PCIBus *bus, int bus_num, uint8_t devfn)
>      return bus->devices[devfn];
>  }
>  
> +static void pci_function_is_valid(PCIBus *bus, PCIDevice *d, void *opaque)
> +{
> +    PCIDeviceClass *pc = PCI_DEVICE_GET_CLASS(d);
> +    Error **errp = opaque;
> +
> +    if (*errp) {
> +        return;
> +    }
> +
> +    if (pc->is_valid_func) {
> +        pc->is_valid_func(d, errp);
> +    }
> +}
> +
>  static void pci_qdev_realize(DeviceState *qdev, Error **errp)
>  {
>      PCIDevice *pci_dev = (PCIDevice *)qdev;
> @@ -1984,6 +1998,21 @@ static void pci_qdev_realize(DeviceState *qdev, Error **errp)
>          pci_qdev_unrealize(DEVICE(pci_dev), NULL);
>          return;
>      }
> +
> +    /*
> +     *  Hot-added function number 0 indicates the closure of the slot, it is
> +     *  time to check whether all functions under the same bus is valid.
> +     */
> +    if (DEVICE(pci_dev)->hotplugged &&
> +        pci_get_function_0(pci_dev) == pci_dev) {
> +        pci_for_each_device(bus, pci_bus_num(bus),
> +                            pci_function_is_valid, &local_err);
> +        if (local_err) {
> +            error_propagate(errp, local_err);
> +            pci_qdev_unrealize(DEVICE(pci_dev), NULL);
> +            return;
> +        }
> +    }
>  }
>  
>  static void pci_default_realize(PCIDevice *dev, Error **errp)
> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
> index 772692f..678f305 100644
> --- a/include/hw/pci/pci.h
> +++ b/include/hw/pci/pci.h
> @@ -205,6 +205,7 @@ typedef struct PCIDeviceClass {
>  
>      void (*realize)(PCIDevice *dev, Error **errp);
>      int (*init)(PCIDevice *dev);/* TODO convert to realize() and remove */
> +    void (*is_valid_func)(PCIDevice *dev, Error **errp);
>      PCIUnregisterFunc *exit;
>      PCIConfigReadFunc *config_read;
>      PCIConfigWriteFunc *config_write;
> -- 
> 1.8.3.1
> 
>