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

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

[Wei Yang]

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(-)

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);
-- 
1.7.9.5

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

[Alex Williamson]

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);