Re: [PATCH V2] vfio-pci: Fix the check on pci device type in vfio_pci_probe()

[Alex Williamson <alex.williamson@redhat.com>]

On Tue, 2014-12-23 at 10:58 +0800, Wei Yang wrote:
> Current vfio-pci just supports normal pci device, so vfio_pci_probe() will
> return if the pci device is not a normal device. While current code makes a
> mistake. PCI_HEADER_TYPE is the offset in configuration space of the device
> type, but we use this value to mask the type value.
> 
> This patch fixs this by do the check directly on the pci_dev->hdr_type.
> 
> Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
> 
> V2:
>    * Fix the problem by checking pci_dev->hdr_type
> 
> ---
>  drivers/vfio/pci/vfio_pci.c |    4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)

Applied to my for-linus branch for v3.19.  I've also tagged it for
stable.  Thanks,

Alex

> diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
> index 9558da3..2f8a055 100644
> --- a/drivers/vfio/pci/vfio_pci.c
> +++ b/drivers/vfio/pci/vfio_pci.c
> @@ -839,13 +839,11 @@ static const struct vfio_device_ops vfio_pci_ops = {
>  
>  static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>  {
> -	u8 type;
>  	struct vfio_pci_device *vdev;
>  	struct iommu_group *group;
>  	int ret;
>  
> -	pci_read_config_byte(pdev, PCI_HEADER_TYPE, &type);
> -	if ((type & PCI_HEADER_TYPE) != PCI_HEADER_TYPE_NORMAL)
> +	if (pdev->hdr_type != PCI_HEADER_TYPE_NORMAL)
>  		return -EINVAL;
>  
>  	group = iommu_group_get(&pdev->dev);