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

[Santosh Shukla <sshukla@mvista.com>]

On Fri, Jan 15, 2016 at 6:13 PM, Santosh Shukla <sshukla@mvista.com> wrote:
> On Fri, Jan 15, 2016 at 11:57 AM, Yuanhan Liu
> <yuanhan.liu@linux.intel.com> wrote:
>> 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@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.
>>
>
> yes, I'll replace is_vfio with pci_dev->kdrv.
>
>>> +                                      */
>>> +     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.
>
> Okay, Before rebasing my v5 patch on your 1.0 virtio patch, I like to
> understand which qemu version support virtio 1.0 spec?

Ignore, I figured out in other thread,
qemu version >2.4, such as 2.4.1 or 2.5.0.

>>> +};
>>> +
>>>  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 "?:".
>>

Ok.
>>         --yliu