[dpdk-dev] [PATCH] net/virtio: fix use_msix get the wrong value

Yuanhan Liu yliu at fridaylinux.org
Wed Nov 1 16:40:13 CET 2017


On Tue, Oct 31, 2017 at 05:44:56PM +0800, Zhiyong Yang wrote:
> When running l3fwd-power to test virtio rxq interrupt using vfio
> pci noiommu mode, startup fails.

What errors have you met?

> In the function virtio_read_caps,
> the code if (flags & PCI_MSIX_ENABLE) intends to double check
> if vfio msix is enabled or not. However, it is indeed not valid.
> Come back to l3fwd-power, use_msix is not assigned to the right
> value "1". The patch fixes the issue.

Jianfeng, could you review it? You are the last author changed the code.
Will it break your case?

	--yliu

> Fixes: cb482cb3a305 ("net/virtio: fix MAC address read")
> Signed-off-by: Zhiyong Yang <zhiyong.yang at intel.com>
> ---
>  drivers/net/virtio/virtio_pci.c | 11 +----------
>  1 file changed, 1 insertion(+), 10 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtio_pci.c b/drivers/net/virtio/virtio_pci.c
> index 55b717c03..be5b07a58 100644
> --- a/drivers/net/virtio/virtio_pci.c
> +++ b/drivers/net/virtio/virtio_pci.c
> @@ -580,8 +580,6 @@ get_cfg_addr(struct rte_pci_device *dev, struct virtio_pci_cap *cap)
>  	return base + offset;
>  }
>  
> -#define PCI_MSIX_ENABLE 0x8000
> -
>  static int
>  virtio_read_caps(struct rte_pci_device *dev, struct virtio_hw *hw)
>  {
> @@ -609,14 +607,7 @@ virtio_read_caps(struct rte_pci_device *dev, struct virtio_hw *hw)
>  		}
>  
>  		if (cap.cap_vndr == PCI_CAP_ID_MSIX) {
> -			/* Transitional devices would also have this capability,
> -			 * that's why we also check if msix is enabled.
> -			 * 1st byte is cap ID; 2nd byte is the position of next
> -			 * cap; next two bytes are the flags.
> -			 */
> -			uint16_t flags = ((uint16_t *)&cap)[1];
> -
> -			if (flags & PCI_MSIX_ENABLE)
> +			if (dev->intr_handle.type == RTE_INTR_HANDLE_VFIO_MSIX)
>  				hw->use_msix = 1;
>  		}
>  
> -- 
> 2.13.3


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