[dpdk-dev] [PATCH v3 07/21] net/virtio: implement transmit path for packed queues

[Jens Freimann]

On Fri, Apr 06, 2018 at 09:56:06AM +0200, Maxime Coquelin wrote:
>
>
>On 04/05/2018 12:10 PM, Jens Freimann wrote:
>>This implements the transmit path for devices with
>>support for Virtio 1.1.
>>
>>Add the feature bit for Virtio 1.1 and enable code to
>>add buffers to vring and mark descriptors as available.
>>
>>This is based on a patch by Yuanhan Liu.
>>
>>Signed-off-by: Jens Freiman <jfreimann at redhat.com>
>>---
>>  drivers/net/virtio/virtio_ethdev.c |   8 ++-
>>  drivers/net/virtio/virtio_ethdev.h |   3 ++
>>  drivers/net/virtio/virtio_rxtx.c   | 102 ++++++++++++++++++++++++++++++++++++-
>>  3 files changed, 111 insertions(+), 2 deletions(-)
>>
>>diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
>>index cccefafe9..089a161ac 100644
>>--- a/drivers/net/virtio/virtio_ethdev.c
>>+++ b/drivers/net/virtio/virtio_ethdev.c
>>@@ -383,6 +383,8 @@ virtio_init_queue(struct rte_eth_dev *dev, uint16_t vtpci_queue_idx)
>>  	vq->hw = hw;
>>  	vq->vq_queue_index = vtpci_queue_idx;
>>  	vq->vq_nentries = vq_size;
>>+	if (vtpci_packed_queue(hw))
>>+		vq->vq_ring.avail_wrap_counter = 1;
>>  	/*
>>  	 * Reserve a memzone for vring elements
>>@@ -1328,7 +1330,11 @@ set_rxtx_funcs(struct rte_eth_dev *eth_dev)
>>  		eth_dev->rx_pkt_burst = &virtio_recv_pkts;
>>  	}
>>-	if (hw->use_simple_tx) {
>>+	if (vtpci_packed_queue(hw)) {
>>+		PMD_INIT_LOG(INFO, "virtio: using virtio 1.1 Tx path on port %u",
>>+			eth_dev->data->port_id);
>>+		eth_dev->tx_pkt_burst = virtio_xmit_pkts_packed;
>>+	} else if (hw->use_simple_tx) {
>>  		PMD_INIT_LOG(INFO, "virtio: using simple Tx path on port %u",
>>  			eth_dev->data->port_id);
>>  		eth_dev->tx_pkt_burst = virtio_xmit_pkts_simple;
>>diff --git a/drivers/net/virtio/virtio_ethdev.h b/drivers/net/virtio/virtio_ethdev.h
>>index bb40064ea..d457013cb 100644
>>--- a/drivers/net/virtio/virtio_ethdev.h
>>+++ b/drivers/net/virtio/virtio_ethdev.h
>>@@ -36,6 +36,7 @@
>>  	 1ULL << VIRTIO_NET_F_GUEST_ANNOUNCE |	\
>>  	 1u << VIRTIO_RING_F_INDIRECT_DESC |    \
>>  	 1ULL << VIRTIO_F_VERSION_1       |	\
>>+	 1ULL << VIRTIO_F_RING_PACKED     |	\
>
>Should it really advertise VIRTIO_F_RING_PACKED unconditionally, as it
>is not yet fully supported? (non-pow2, indirect descs, etc...)

We can advertise packed ring but have VIRTIO_F_INDIRECT_DESC disabled.
non-pow2 needs to be integrated thoug and will be in v4.

regards,
Jens 
>
>>  	 1ULL << VIRTIO_F_IOMMU_PLATFORM)
>>  #define VIRTIO_PMD_SUPPORTED_GUEST_FEATURES	\