[dpdk-dev] [PATCH v1] virtio: Use cpuflag for vector api

[Santosh Shukla]

On Tue, Mar 1, 2016 at 2:41 PM, Qiu, Michael <michael.qiu at intel.com> wrote:
> On 2/26/2016 4:53 PM, Santosh Shukla wrote:
>> Check cpuflag macro before using vectored api.
>> -virtio_recv_pkts_vec() uses _sse3__ simd instruction for now so added cpuflag.
>> - Also wrap other vectored freind api ie..
>> 1) virtqueue_enqueue_recv_refill_simple
>> 2) virtio_rxq_vec_setup
>>
>> todo:
>> 1) Move virtio_recv_pkts_vec() implementation to
>>    drivers/virtio/virtio_vec_<arch>.h file.
>> 2) Remove use_simple_rxtx flag, so that virtio/virtio_vec_<arch>.h
>>    files to provide vectored/non-vectored rx/tx apis.
>>
>> Signed-off-by: Santosh Shukla <sshukla at mvista.com>
>> ---
>> - v1: This is a rework of patch [1].
>> Note: This patch will let non-x86 arch to use virtio pmd.
>>
>> [1] http://dpdk.org/dev/patchwork/patch/10429/
>>
>>  drivers/net/virtio/virtio_rxtx.c        |   16 +++++++++++++++-
>>  drivers/net/virtio/virtio_rxtx.h        |    2 ++
>>  drivers/net/virtio/virtio_rxtx_simple.c |   11 ++++++++++-
>>  3 files changed, 27 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
>> index 41a1366..ec0b8de 100644
>> --- a/drivers/net/virtio/virtio_rxtx.c
>> +++ b/drivers/net/virtio/virtio_rxtx.c
>> @@ -67,7 +67,9 @@
>>  #define VIRTIO_SIMPLE_FLAGS ((uint32_t)ETH_TXQ_FLAGS_NOMULTSEGS | \
>>       ETH_TXQ_FLAGS_NOOFFLOADS)
>>
>> +#ifdef RTE_MACHINE_CPUFLAG_SSSE3
>>  static int use_simple_rxtx;
>> +#endif
>>
>>
>
> I don't think so much #ifdef ... #endif in *.c file is a good choice.
> Would you consider let it only in header file like:
>
> in drivers/net/virtio/virtio_rxtx.h
>
> [...]
>
> #ifdef RTE_MACHINE_CPUFLAG_SSSE3
> int virtio_rxq_vec_setup(struct virtqueue *rxq);
>
> int virtqueue_enqueue_recv_refill_simple(struct virtqueue *vq,
>         struct rte_mbuf *m);
> #else
> int virtio_rxq_vec_setup(__rte_unused struct virtqueue *rxq) {return -1;}
> int virtqueue_enqueue_recv_refill_simple(__rte_unused struct virtqueue *vq,
>                                          __rte_unused struct rte_mbuf *m) {
>         return -1;
> }
> #endif
>
> and remove most #ifdef ... #endif in *.c file.
>

I guess, above approach wont work for non-x86 arch, ad those func are
dummy, right? also code wont build for arm/non-86 arch because
tx/rx_pkt_burst callback will be using x86 specific virtio vec rx/tx
api.

> Thanks,
> Michael