Re: [dpdk-dev] [PATCH v4 01/14] virtio: Introduce config RTE_VIRTIO_INC_VECTOR

[Santosh Shukla <sshukla@mvista.com>]

On Fri, Jan 15, 2016 at 12:21 PM, Yuanhan Liu
<yuanhan.liu@linux.intel.com> wrote:
> On Thu, Jan 14, 2016 at 06:58:24PM +0530, Santosh Shukla wrote:
>> virtio_recv_pkts_vec and other virtio vector friend apis are written for sse/avx
>> instructions. For arm64 in particular, virtio vector implementation does not
>> exist(todo).
>>
>> So virtio pmd driver wont build for targets like i686, arm64.  By making
>> RTE_VIRTIO_INC_VECTOR=n, Driver can build for non-sse/avx targets and will work
>> in non-vectored virtio mode.
>
> While revisiting this patch, I'm thinking you may squash both patch 2
> and patch 11 into this one.
>

Make sense!, we'll do in v5.

>>
>> Signed-off-by: Santosh Shukla <sshukla@mvista.com>
>> ---
>>  config/common_linuxapp           |    1 +
>>  drivers/net/virtio/Makefile      |    2 +-
>>  drivers/net/virtio/virtio_rxtx.c |    7 +++++++
>>  3 files changed, 9 insertions(+), 1 deletion(-)
>>
>> diff --git a/config/common_linuxapp b/config/common_linuxapp
>> index 74bc515..8677697 100644
>> --- a/config/common_linuxapp
>> +++ b/config/common_linuxapp
>> @@ -274,6 +274,7 @@ CONFIG_RTE_LIBRTE_VIRTIO_DEBUG_RX=n
>>  CONFIG_RTE_LIBRTE_VIRTIO_DEBUG_TX=n
>>  CONFIG_RTE_LIBRTE_VIRTIO_DEBUG_DRIVER=n
>>  CONFIG_RTE_LIBRTE_VIRTIO_DEBUG_DUMP=n
>> +CONFIG_RTE_VIRTIO_INC_VECTOR=y
>>
>>  #
>>  # Compile burst-oriented VMXNET3 PMD driver
>> diff --git a/drivers/net/virtio/Makefile b/drivers/net/virtio/Makefile
>> index 43835ba..25a842d 100644
>> --- a/drivers/net/virtio/Makefile
>> +++ b/drivers/net/virtio/Makefile
>> @@ -50,7 +50,7 @@ SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtqueue.c
>>  SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_pci.c
>>  SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_rxtx.c
>>  SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_ethdev.c
>> -SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_rxtx_simple.c
>> +SRCS-$(CONFIG_RTE_VIRTIO_INC_VECTOR) += virtio_rxtx_simple.c
>>
>>  # this lib depends upon:
>>  DEPDIRS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += lib/librte_eal lib/librte_ether
>> diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
>> index 74b39ef..23be1ff 100644
>> --- a/drivers/net/virtio/virtio_rxtx.c
>> +++ b/drivers/net/virtio/virtio_rxtx.c
>> @@ -438,7 +438,9 @@ virtio_dev_rx_queue_setup(struct rte_eth_dev *dev,
>>
>>       dev->data->rx_queues[queue_idx] = vq;
>>
>> +#ifdef RTE_VIRTIO_INC_VECTOR
>>       virtio_rxq_vec_setup(vq);
>> +#endif
>
> You should put such macros for the declaration in virtio_rxtx.h as well.
>
>
> And note that you may miss one:
>
>
>     325                         /******************************************
>     326                         *         Enqueue allocated buffers        *
>     327                         *******************************************/
>     328                         if (use_simple_rxtx)
> ==> 329                                 error = virtqueue_enqueue_recv_refill_simple(vq, m);
>     330                         else
>     331                                 error = virtqueue_enqueue_recv_refill(vq, m);
>     332                         if (error) {
>     333                                 rte_pktmbuf_free(m);
>     334                                 break;
>     335                         }
>
>
> virtqueue_enqueue_recv_refill_simple() is defined inside virtio_rxtx_simple.c,
> which is built only when CONFIG_RTE_VIRTIO_INC_VECTOR is set. But I see no
> such check here.
>
> Note that this will not break the build, as gcc just ignores it, for use_simple_rxtx
> is 0 by default, thus the "if" part code is not compiled at all. Even for that,
> I think it's better to put an explicit macro check here.
>

we'll make changes in v5, Thanks for review comment.

>         --yliu