Re: [Qemu-devel] [PATCH v2 06/11] pci: add a is_valid_func callback to check device if complete

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

On Mon, Mar 07, 2016 at 11:22:59AM +0800, Cao jin wrote:
> From: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
> 
> Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>

So if you create a mess, you discover it when
you later add function 0.
Why not call this when function is added?
O(N^2) on # of functions, but that # is up to 256 so maybe
that is not too bad.

> ---
>  hw/pci/pci.c         | 39 +++++++++++++++++++++++++++++++++++++++
>  include/hw/pci/pci.h |  1 +
>  2 files changed, 40 insertions(+)
> 
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index d940f79..72650c5 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -1836,6 +1836,31 @@ PCIDevice *pci_find_device(PCIBus *bus, int bus_num, uint8_t devfn)
>      return bus->devices[devfn];
>  }
>  
> +static void pci_bus_check_device(PCIDevice *pdev, Error **errp)
> +{
> +    PCIBus *bus = pdev->bus;
> +    PCIDeviceClass *pc;
> +    int i;
> +    Error *local_err = NULL;
> +
> +    for (i = 0; i < ARRAY_SIZE(bus->devices); ++i) {
> +        if (!bus->devices[i]) {
> +            continue;
> +        }
> +
> +        pc = PCI_DEVICE_GET_CLASS(bus->devices[i]);
> +        if (!pc->is_valid_func) {
> +            continue;
> +        }
> +
> +        pc->is_valid_func(bus->devices[i], &local_err);
> +        if (local_err) {
> +            error_propagate(errp, local_err);
> +            return;
> +        }
> +    }
> +}
> +
>  static void pci_qdev_realize(DeviceState *qdev, Error **errp)
>  {
>      PCIDevice *pci_dev = (PCIDevice *)qdev;
> @@ -1878,6 +1903,20 @@ static void pci_qdev_realize(DeviceState *qdev, Error **errp)
>          pci_qdev_unrealize(DEVICE(pci_dev), NULL);
>          return;
>      }
> +
> +    /*
> +     *  If the function is func 0, indicate the closure of the slot.
> +     *  then we get the chance to check all functions on same device
> +     *  if valid.
> +     */
> +    if (pci_get_function_0(pci_dev) == pci_dev) {
> +        pci_bus_check_device(pci_dev, &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 dedf277..4e56256 100644
> --- a/include/hw/pci/pci.h
> +++ b/include/hw/pci/pci.h
> @@ -191,6 +191,7 @@ 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;
> -- 
> 1.9.3
> 
>