Re: [dpdk-dev] [PATCH v7 4/4] eal/linux: vfio: add pci ioport support

[Santosh Shukla <sshukla@mvista.com>]

On Mon, Feb 8, 2016 at 2:21 PM, David Marchand <david.marchand@6wind.com> wrote:
> On Sun, Feb 7, 2016 at 2:51 PM, Santosh Shukla <sshukla@mvista.com> wrote:
>> @@ -999,37 +1000,56 @@ int
>>  pci_vfio_ioport_map(struct rte_pci_device *dev, int bar,
>>                     struct rte_pci_ioport *p)
>
> p is passed as a value, not a reference ...
>
>>  {
>> -       RTE_SET_USED(dev);
>> -       RTE_SET_USED(bar);
>> -       RTE_SET_USED(p);
>> -       return -1;
>> +       if (bar < VFIO_PCI_BAR0_REGION_INDEX ||
>> +           bar > VFIO_PCI_BAR5_REGION_INDEX) {
>> +               RTE_LOG(ERR, EAL, "invalid bar (%d)!\n", bar);
>> +               return -1;
>> +       }
>> +
>> +       p = rte_zmalloc("VFIO_IOPORT", sizeof(*p), 0);
>
> ... so I don't think this allocation does what you expected.
>
> Anyway, you don't need to allocate a rte_pci_ioport object with current api.
> You already have a valid object passed by caller.
> You only need to initialise it.
>
>
>> +       if (p == NULL) {
>> +               RTE_LOG(ERR, EAL, "cannot alloc vfio ioport mem\n");
>> +               return -1;
>> +       }
>> +
>> +       p->dev = dev;
>
> Does not hurt to do this, but p->dev is already set by caller on ret
> == 0 (rte_eal_pci_ioport_map).
>
>

so far I didn't found caller setting p->dev (looked at virtio pmd
driver), In-fact I tried to use w/o setting p->dev=dev and application
crashed, stating segfault :).

So I am keeping this one in next revision.
>>
>>  void
>>  pci_vfio_ioport_read(struct rte_pci_ioport *p,
>>                      void *data, size_t len, off_t offset)
>>  {
>> -       RTE_SET_USED(p);
>> -       RTE_SET_USED(data);
>> -       RTE_SET_USED(len);
>> -       RTE_SET_USED(offset);
>> +       const struct rte_intr_handle *intr_handle = &p->dev->intr_handle;
>
> Missing blank line between declaration and code.

checkpatch.sh didn't ntocied though, which all param you use in
checkpatch, I just do
./checkpatch.sh --no-tree *.patch

>
>> +       if (pread64(intr_handle->vfio_dev_fd, data,
>> +                   len, p->offset + offset) <= 0)
>> +               RTE_LOG(ERR, EAL,
>> +                       "Can't read from PCI bar (%" PRIu64 ") : offset (%x)\n",
>> +                       VFIO_GET_REGION_IDX(p->offset), (int)offset);
>>  }
>>
>>  void
>>  pci_vfio_ioport_write(struct rte_pci_ioport *p,
>>                       const void *data, size_t len, off_t offset)
>>  {
>> -       RTE_SET_USED(p);
>> -       RTE_SET_USED(data);
>> -       RTE_SET_USED(len);
>> -       RTE_SET_USED(offset);
>> +       const struct rte_intr_handle *intr_handle = &p->dev->intr_handle;
>
> Idem.
>
>> +       if (pwrite64(intr_handle->vfio_dev_fd, data,
>> +                    len, p->offset + offset) <= 0)
>> +               RTE_LOG(ERR, EAL,
>> +                       "Can't write to PCI bar (%" PRIu64 ") : offset (%x)\n",
>> +                       VFIO_GET_REGION_IDX(p->offset), (int)offset);
>>  }
>>
>>  int
>>  pci_vfio_ioport_unmap(struct rte_pci_ioport *p)
>>  {
>> -       RTE_SET_USED(p);
>> -       return -1;
>> +       if (p == NULL)
>> +               return -1;
>> +       else {
>> +               rte_free(p);
>> +               return 0;
>> +       }
>>  }
>
> Since you have nothing to allocate, nothing to free here ?
>

Removed, Thanks
>
> --
> David Marchand