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

[Jason Wang <jasowang@redhat.com>]

On 01/14/2016 09:28 PM, 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@mvista.com>
> ---
> v3->v4:
> - Removed #indef RTE_EAL_VFIO and made it arch agnostic such now virtio_pci
>   rd/wr api to handle both vfio and ig_uio/ioport interfaces, depending upon
>   is_vfio flags set or unset.
> - Tested for x86 for igb_uio and vfio interface, also  tested for arm64 for vfio
>   interface.
>
> drivers/net/virtio/virtio_pci.h |   84 ++++++++++++++++++++++++++++++++-------
>  1 file changed, 70 insertions(+), 14 deletions(-)

Interesting. I'm working on IOMMU cooperation with virtio[1]. For pmd,
it looks like the only thing missed is RTE_PCI_DRV_NEED_MAPPING for
virito-net pmd.

So I'm curious whether this is still necessary if IOMMU can work with
virito in the future.

[1] https://www.mail-archive.com/qemu-devel@nongnu.org/msg337079.html

Thanks

>
> diff --git a/drivers/net/virtio/virtio_pci.h b/drivers/net/virtio/virtio_pci.h
> index 8b5b031..8526c07 100644
> --- a/drivers/net/virtio/virtio_pci.h
> +++ b/drivers/net/virtio/virtio_pci.h
> @@ -46,6 +46,8 @@
>  #endif
>  
>  #include <rte_ethdev.h>
> +#include <stdbool.h>
> +#include "virtio_vfio_rw.h"
>  
>  struct virtqueue;
>  
> @@ -165,6 +167,14 @@ struct virtqueue;
>   */
>  #define VIRTIO_MAX_VIRTQUEUES 8
>  
> +/* For vfio only */
> +struct virtio_vfio_dev {
> +	bool		is_vfio;	/* True: vfio i/f,
> +					 * False: not a vfio i/f
> +					 */
> +	struct rte_pci_device *pci_dev; /* vfio dev */
> +};
> +
>  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;								\
> +})
> +
> +#define VIRTIO_WRITE_REG_1(hw, reg, value)				\
> +({									\
> +	struct virtio_vfio_dev *vdev;					\
> +	(vdev) = (&(hw)->dev);						\
> +	(((vdev)->is_vfio) ?						\
> +	(ioport_outb_p(((vdev)->pci_dev), reg, (uint8_t)(value))) :	\
> +	(outb_p((unsigned char)(value), (VIRTIO_PCI_REG_ADDR((hw), (reg)))))); \
> +})
> +
> +#define VIRTIO_READ_REG_2(hw, reg)					\
> +({									\
> +	uint16_t ret;							\
> +	struct virtio_vfio_dev *vdev;					\
> +	(vdev) = (&(hw)->dev);						\
> +	(((vdev)->is_vfio) ?						\
> +	(ioport_inw(((vdev)->pci_dev), reg, &ret)) :			\
> +	((ret) = (inw((VIRTIO_PCI_REG_ADDR((hw), (reg)))))));		\
> +	ret;								\
> +})
> +
> +#define VIRTIO_WRITE_REG_2(hw, reg, value)				\
> +({									\
> +	struct virtio_vfio_dev *vdev;					\
> +	(vdev) = (&(hw)->dev);						\
> +	(((vdev)->is_vfio) ?						\
> +	(ioport_outw_p(((vdev)->pci_dev), reg, (uint16_t)(value))) :	\
> +	(outw_p((unsigned short)(value), (VIRTIO_PCI_REG_ADDR((hw), (reg)))))); \
> +})
> +
> +#define VIRTIO_READ_REG_4(hw, reg)					\
> +({									\
> +	uint32_t ret;							\
> +	struct virtio_vfio_dev *vdev;					\
> +	(vdev) = (&(hw)->dev);						\
> +	(((vdev)->is_vfio) ?						\
> +	(ioport_inl(((vdev)->pci_dev), reg, &ret)) :			\
> +	((ret) = (inl((VIRTIO_PCI_REG_ADDR((hw), (reg)))))));		\
> +	ret;								\
> +})
> +
> +#define VIRTIO_WRITE_REG_4(hw, reg, value)				\
> +({									\
> +	struct virtio_vfio_dev *vdev;					\
> +	(vdev) = (&(hw)->dev);						\
> +	(((vdev)->is_vfio) ?						\
> +	(ioport_outl_p(((vdev)->pci_dev), reg, (uint32_t)(value))) :	\
> +	(outl_p((unsigned int)(value), (VIRTIO_PCI_REG_ADDR((hw), (reg)))))); \
> +})
>  
>  static inline int
>  vtpci_with_feature(struct virtio_hw *hw, uint32_t bit)