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Re: [Minios-devel] [UNIKRAFT PATCH v2 2/7] plat/drivers: Configure virtio-net device
On 19.10.18 15:39, Sharan Santhanam wrote:
This patch provides the implementation callbacks to configure the
virtio device from libuknet
Signed-off-by: Sharan Santhanam <sharan.santhanam@xxxxxxxxx>
Signed-off-by: Razvan Cojocaru <razvan.cojocaru93@xxxxxxxxx>
---
plat/drivers/virtio/virtio_net.c | 174 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 170 insertions(+), 4 deletions(-)
diff --git a/plat/drivers/virtio/virtio_net.c b/plat/drivers/virtio/virtio_net.c
index 5617039..4edb34b 100644
--- a/plat/drivers/virtio/virtio_net.c
+++ b/plat/drivers/virtio/virtio_net.c
@@ -161,6 +161,9 @@ static void virtio_net_info_get(struct uk_netdev *dev,
static inline void virtio_netdev_feature_set(struct virtio_net_device *vndev);
static int virtio_netdev_configure(struct uk_netdev *n,
const struct uk_netdev_conf *conf);
+static int virtio_netdev_rxtx_alloc(struct virtio_net_device *vndev,
+ const struct uk_netdev_conf *conf);
+static int virtio_netdev_feature_negotiate(struct virtio_net_device *vndev);
static struct uk_netdev_tx_queue *virtio_netdev_tx_queue_setup(
struct uk_netdev *n, uint16_t queue_id,
uint16_t nb_desc,
@@ -267,30 +270,193 @@ static int virtio_netdev_txq_info_get(struct uk_netdev
*dev,
static unsigned virtio_net_promisc_get(struct uk_netdev *n)
{
+ struct virtio_net_device *d;
+
UK_ASSERT(n);
- return 0;
+ d = to_virtionetdev(n);
+ return d->promisc;
}
static const struct uk_hwaddr *virtio_net_mac_get(struct uk_netdev *n)
{
+ struct virtio_net_device *d;
+
UK_ASSERT(n);
- return NULL;
+ d = to_virtionetdev(n);
+ return &d->hw_addr;
}
static __u16 virtio_net_mtu_get(struct uk_netdev *n)
{
+ struct virtio_net_device *d;
+
UK_ASSERT(n);
- return 0;
+ d = to_virtionetdev(n);
+ return d->mtu;
+}
+
+static int virtio_netdev_feature_negotiate(struct virtio_net_device *vndev)
+{
+ __u64 host_features = 0;
+ __u16 hw_len;
+ int rc = 0;
+
+ /**
+ * Read device feature bits, and write the subset of feature bits
+ * understood by the OS and driver to the device. During this step the
+ * driver MAY read (but MUST NOT write) the device-specific
+ * configuration fields to check that it can support the device before
+ * accepting it.
+ */
+ host_features = virtio_feature_get(vndev->vdev);
+ if (!virtio_has_features(host_features, VIRTIO_NET_F_MAC)) {
+ /**
+ * The feature that aren't supported are usually masked out and
+ * provided with default value. In this case we need to
+ * report an error as we don't support generation of random
+ * MAC Address.
+ */
+ uk_pr_err("Host system does not offer MAC feature\n");
+ rc = -EINVAL;
+ goto exit;
+ }
+
+ /**
+ * According to Virtio specification, section 2.3.1. Config fields
+ * greater than 32-bits cannot be atomically read. We may need to
+ * reconsider providing generic read/write function for all these
+ * virtio device in a separate header file which could be reused across
+ * different virtio devices.
+ */
+ hw_len = virtio_config_get(vndev->vdev,
+ __offsetof(struct virtio_net_config, mac),
+ &vndev->hw_addr.addr_bytes[0],
+ UK_NETDEV_HWADDR_LEN, 1);
+ if (unlikely(hw_len != UK_NETDEV_HWADDR_LEN)) {
+ uk_pr_err("Failed to retrieve the mac address from device\n");
+ rc = -EAGAIN;
+ goto exit;
+ }
+ rc = 0;
+
+ /**
+ * Mask out features supported by both driver and device.
+ */
+ vndev->vdev->features &= host_features;
+ virtio_feature_set(vndev->vdev, vndev->vdev->features);
+exit:
+ return rc;
+}
+
+static int virtio_netdev_rxtx_alloc(struct virtio_net_device *vndev,
+ const struct uk_netdev_conf *conf)
+{
+ int rc = 0;
+ int i = 0;
+ int vq_avail = 0;
+ int total_vqs = conf->nb_rx_queues + conf->nb_tx_queues;
+ __u16 qdesc_size[total_vqs];
+
+ if (conf->nb_rx_queues != 1 || conf->nb_tx_queues != 1) {
+ uk_pr_err("Queue combination not supported: %"__PRIu16"/%"__PRIu16"
rx/tx\n",
+ conf->nb_rx_queues, conf->nb_tx_queues);
+
+ return -ENOTSUP;
+ }
+
+ vndev->rxqs = uk_malloc(a, sizeof(*vndev->rxqs) * conf->nb_rx_queues);
+ vndev->txqs = uk_malloc(a, sizeof(*vndev->txqs) * conf->nb_tx_queues);
+ if (unlikely(!vndev->rxqs || !vndev->txqs)) {
+ uk_pr_err("Failed to allocate memory for queue management\n");
+ rc = -ENOMEM;
+ goto err_free_txrx;
+ }
Hum, I think this is fine for this first version. We probably should use
the same allocator for the management of a queue as we use for the
queue. With this we would make sure that NUMA would be supported
(assumed you have an allocator for each NUMA node). However, this
allocation would need to happen effectively in the
virtio_netdev_(rx|tx)_queue_setup() and struct virtio_net_device would
need to be changed for this. Maybe you could add a small TODO comment?
+
+ vq_avail = virtio_find_vqs(vndev->vdev, total_vqs, qdesc_size);
+ if (unlikely(vq_avail != total_vqs)) {
+ uk_pr_err("Expected: %d queues, Found: %d queues\n",
+ total_vqs, vq_avail);
+ rc = -ENOMEM;
+ goto err_free_txrx;
+ }
+
+ /**
+ * The virtqueue are organized as:
+ * Virtqueue-rx0
+ * Virtqueue-tx0
+ * Virtqueue-rx1
+ * Virtqueue-tx1
+ * ...
+ * Virtqueue-ctrlq
+ */
+ for (i = 0; i < vndev->max_vqueue_pairs; i++) {
+ /**
+ * Initialize the received queue with the information received
+ * from the device.
+ */
+ vndev->rxqs[i].hwvq_id = 2 * i;
+ vndev->rxqs[i].max_nb_desc = qdesc_size[vndev->rxqs[i].hwvq_id];
+ uk_sglist_init(&vndev->rxqs[i].sg,
+ (sizeof(vndev->rxqs[i].sgsegs) /
+ sizeof(vndev->rxqs[i].sgsegs[0])),
+ &vndev->rxqs[i].sgsegs[0]);
This sglists made me think that it is better to allocate them together
with the queue descriptors. It is safer in terms of NUMA. We do not
support NUMA yet - so I am fine for now - but we may NUMA support in the
future. In this case we should re-visit this.
+
+ /**
+ * Initialize the transmit queue with the information received
+ * from the device.
+ */
+ vndev->txqs[i].hwvq_id = (2 * i) + 1;
+ vndev->txqs[i].max_nb_desc = qdesc_size[vndev->txqs[i].hwvq_id];
+ uk_sglist_init(&vndev->txqs[i].sg,
+ (sizeof(vndev->txqs[i].sgsegs) /
+ sizeof(vndev->txqs[i].sgsegs[0])),
+ &vndev->txqs[i].sgsegs[0]);
+ }
+exit:
+ return rc;
+
+err_free_txrx:
+ if (!vndev->rxqs)
+ uk_free(a, vndev->rxqs);
+ if (!vndev->txqs)
+ uk_free(a, vndev->txqs);
+ goto exit;
}
static int virtio_netdev_configure(struct uk_netdev *n,
- const struct uk_netdev_conf *conf __unused)
+ const struct uk_netdev_conf *conf)
{
int rc = 0;
+ struct virtio_net_device *vndev;
UK_ASSERT(n);
+ UK_ASSERT(conf);
+ vndev = to_virtionetdev(n);
+
+ rc = virtio_netdev_feature_negotiate(vndev);
+ if (rc != 0) {
+ uk_pr_err("Failed to negotiate the device feature %d\n", rc);
+ goto err_negotiate_feature;
+ }
+ rc = virtio_netdev_rxtx_alloc(vndev, conf);
+ if (rc != 0) {
+ uk_pr_err("Failed to allocate the rx and tx rings %d\n", rc);
Are these really the rings with the descriptors already? Isn't it the
queue management?
+ goto err_negotiate_feature;
+ }
+
+ /* Initialize the count of the virtio-net device */
+ vndev->rx_vqueue_cnt = 0;
+ vndev->tx_vqueue_cnt = 0;
+
+ uk_pr_info("Configured: features=0x%lx max
virtqueue_pairs=%"__PRIu16"\n",
Is an underline character missing between max and virtqueue_pairs?
+ vndev->vdev->features, vndev->max_vqueue_pairs);
+exit:
return rc;
+
+err_negotiate_feature:
+ virtio_dev_status_update(vndev->vdev, VIRTIO_CONFIG_STATUS_FAIL);
+ goto exit;
}
static int virtio_net_rx_intr_enable(struct uk_netdev *n,
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