[dpdk-dev] [PATCH 3/3] virtio-user: add mq in virtual pci driver

[Jianfeng Tan]

Partially implement ctrl-queue to handle control command with class
of VIRTIO_NET_CTRL_MQ and with cmd of VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET
to handle mq support. After filling the command into ctrl-queue, we
dequeue it when notify_queue(), and invoke method from device
emulation to enable/disable queues.

Signed-off-by: Jianfeng Tan <jianfeng.tan at intel.com>
---
 drivers/net/virtio/virtio_user/virtio_user_pci.c | 89 +++++++++++++++++++++++-
 1 file changed, 87 insertions(+), 2 deletions(-)

diff --git a/drivers/net/virtio/virtio_user/virtio_user_pci.c b/drivers/net/virtio/virtio_user/virtio_user_pci.c
index 873e619..aa02c60 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_pci.c
+++ b/drivers/net/virtio/virtio_user/virtio_user_pci.c
@@ -38,6 +38,7 @@
 #include "../virtio_logs.h"
 #include "../virtio_pci.h"
 #include "../virtqueue.h"
+#include "../virtio_ring.h"
 #include "virtio_user_dev.h"
 
 static void
@@ -157,8 +158,10 @@ vdev_setup_queue(struct virtio_hw *hw __rte_unused, struct virtqueue *vq)
 	if (vq->virtio_net_hdr_mz) {
 		vq->virtio_net_hdr_mem =
 			(phys_addr_t)vq->virtio_net_hdr_mz->addr;
-		/* Do it one more time after we reset virtio_net_hdr_mem */
-		vring_hdr_desc_init(vq);
+
+		/* Do it again after we reset virtio_net_hdr_mem for tx */
+		if ((vq->vq_queue_index % VTNET_CQ) == VTNET_TQ)
+			vring_hdr_desc_init(vq);
 	}
 	vq->offset = offsetof(struct rte_mbuf, buf_addr);
 	return 0;
@@ -182,11 +185,93 @@ vdev_del_queue(struct virtio_hw *hw, struct virtqueue *vq)
 	close(uhw->kickfds[vq->vq_queue_index]);
 }
 
+static uint8_t
+handle_mq(struct virtqueue *vq, uint16_t queues)
+{
+	struct virtio_hw *hw = vq->hw;
+	struct virtio_user_hw *uhw = (struct virtio_user_hw *)hw->vdev_private;
+	uint32_t i;
+	uint8_t ret = 0;
+
+	if (queues > uhw->max_queue_pairs) {
+		PMD_INIT_LOG(ERR, "multi-q config %u, but only %u supported",
+			     queues, uhw->max_queue_pairs);
+		return -1;
+	}
+
+	for (i = 0; i < queues; ++i)
+		ret |= virtio_user_enable_queue_pair(uhw, i, 1);
+	for (i = queues; i < uhw->max_queue_pairs; ++i)
+		ret |= virtio_user_enable_queue_pair(uhw, i, 0);
+
+	return ret;
+}
+
+static uint32_t
+handle_ctrl(struct virtqueue *vq, uint16_t desc_idx_hdr)
+{
+	struct virtio_net_ctrl_hdr *hdr;
+	virtio_net_ctrl_ack status = ~0;
+	uint16_t i, desc_idx_data, desc_idx_status;
+	uint32_t num_of_descs = 0;
+
+	/* locate desc for header, data, and status */
+	desc_idx_data = vq->vq_ring.desc[desc_idx_hdr].next;
+	num_of_descs++;
+
+
+	i = desc_idx_data;
+	while (vq->vq_ring.desc[i].flags == VRING_DESC_F_NEXT) {
+		i = vq->vq_ring.desc[i].next;
+		num_of_descs++;
+	}
+
+	/* locate desc for status */
+	desc_idx_status = i;
+	num_of_descs++;
+
+	hdr = (struct virtio_net_ctrl_hdr *)vq->vq_ring.desc[desc_idx_hdr].addr;
+	if (hdr->class == VIRTIO_NET_CTRL_MQ &&
+	    hdr->cmd == VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET) {
+		uint16_t queues;
+
+		queues = *(uint16_t *)vq->vq_ring.desc[desc_idx_data].addr;
+		status = handle_mq(vq, queues);
+	}
+
+	/* Update status */
+	*(virtio_net_ctrl_ack *)vq->vq_ring.desc[desc_idx_status].addr = status;
+
+	return num_of_descs;
+}
+
 static void
 vdev_notify_queue(struct virtio_hw *hw, struct virtqueue *vq)
 {
 	uint64_t buf = 1;
 	struct virtio_user_hw *uhw = (struct virtio_user_hw *)hw->vdev_private;
+	uint16_t avail_idx, desc_idx;
+	struct vring_used_elem *uep;
+	uint32_t num_of_descs;
+
+	if (vq == hw->cvq) {
+		/* Consume avail ring, using used ring idx as first one */
+		while (vq->vq_ring.used->idx != vq->vq_ring.avail->idx) {
+			avail_idx = (vq->vq_ring.used->idx) &
+				(vq->vq_nentries - 1);
+			desc_idx = vq->vq_ring.avail->ring[avail_idx];
+
+			num_of_descs = handle_ctrl(vq, desc_idx);
+
+			/* Update used ring */
+			uep = &vq->vq_ring.used->ring[avail_idx];
+			uep->id = avail_idx;
+			uep->len = num_of_descs;
+
+			vq->vq_ring.used->idx++;
+		}
+		return;
+	}
 
 	if (write(uhw->kickfds[vq->vq_queue_index], &buf, sizeof(buf)) < 0)
 		PMD_DRV_LOG(ERR, "failed to kick backend: %s\n", strerror(errno));
-- 
2.1.4