[dpdk-dev] [PATCH v4 08/14] virtio: pci: extend virtio pci rw api for vfio interface

Yuanhan Liu yuanhan.liu at linux.intel.com
Fri Jan 15 07:27:26 CET 2016


On Thu, Jan 14, 2016 at 06:58:31PM +0530, Santosh Shukla wrote:
> So far virtio handle rw access for uio / ioport interface, This patch to extend
> the support for vfio interface. For that introducing private struct
> virtio_vfio_dev{
> 	- is_vfio
> 	- pci_dev
> 	};
> Signed-off-by: Santosh Shukla <sshukla at mvista.com>
...
> +/* For vfio only */
> +struct virtio_vfio_dev {
> +	bool		is_vfio;	/* True: vfio i/f,
> +					 * False: not a vfio i/f

Well, this is weird; you are adding a flag to tell whether it's a
vfio device __inside__ a vfio struct.

Back to the topic, this flag is not necessary to me: you can
check the pci_dev->kdrv flag.

> +					 */
> +	struct rte_pci_device *pci_dev; /* vfio dev */

Note that I have already added this field into virtio_hw struct
at my latest virtio 1.0 pmd patchset.

While I told you before that you should not develop patches based
on my patcheset, I guess you can do that now. Since it should be
in good shape and close to be merged.

> +};
> +
>  struct virtio_hw {
>  	struct virtqueue *cvq;
>  	uint32_t    io_base;
> @@ -176,6 +186,7 @@ struct virtio_hw {
>  	uint8_t	    use_msix;
>  	uint8_t     started;
>  	uint8_t     mac_addr[ETHER_ADDR_LEN];
> +	struct virtio_vfio_dev dev;
>  };
>  
>  /*
> @@ -231,20 +242,65 @@ outl_p(unsigned int data, unsigned int port)
>  #define VIRTIO_PCI_REG_ADDR(hw, reg) \
>  	(unsigned short)((hw)->io_base + (reg))
>  
> -#define VIRTIO_READ_REG_1(hw, reg) \
> -	inb((VIRTIO_PCI_REG_ADDR((hw), (reg))))
> -#define VIRTIO_WRITE_REG_1(hw, reg, value) \
> -	outb_p((unsigned char)(value), (VIRTIO_PCI_REG_ADDR((hw), (reg))))
> -
> -#define VIRTIO_READ_REG_2(hw, reg) \
> -	inw((VIRTIO_PCI_REG_ADDR((hw), (reg))))
> -#define VIRTIO_WRITE_REG_2(hw, reg, value) \
> -	outw_p((unsigned short)(value), (VIRTIO_PCI_REG_ADDR((hw), (reg))))
> -
> -#define VIRTIO_READ_REG_4(hw, reg) \
> -	inl((VIRTIO_PCI_REG_ADDR((hw), (reg))))
> -#define VIRTIO_WRITE_REG_4(hw, reg, value) \
> -	outl_p((unsigned int)(value), (VIRTIO_PCI_REG_ADDR((hw), (reg))))
> +#define VIRTIO_READ_REG_1(hw, reg)					\
> +({									\
> +	uint8_t ret;							\
> +	struct virtio_vfio_dev *vdev;					\
> +	(vdev) = (&(hw)->dev);						\
> +	(((vdev)->is_vfio) ?						\
> +	(ioport_inb(((vdev)->pci_dev), reg, &ret)) :			\
> +	((ret) = (inb((VIRTIO_PCI_REG_ADDR((hw), (reg)))))));		\
> +	ret;								\
> +})

It becomes unreadable. I'd suggest to define them as iniline
functions, and use "if .. else .." instead of "?:".

	--yliu


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