[UNIKRAFT PATCH 4/4] lib/uknetdev: Introduce ioalign

[Simon Kuenzer <simon.kuenzer@xxxxxxxxx>]

Similar to lib/ukblkdev, we introduce a device info parameter (`struct
uk_netdev_info`) to query alignment requirements of packet buffer areas
for a uknetdev device: `ioalign`.
At the same time the commit clarifies a confusion with the queue
information parameter `nb_align`. This parameter is intended to describe
requirements for sizing a rx/tx queue. The comment is updated and the
`virtio-net` driver is corrected. This fixes commit a52168588.

Signed-off-by: Simon Kuenzer <simon.kuenzer@xxxxxxxxx>
---
 lib/uknetdev/include/uk/netdev_core.h | 5 +++--
 plat/drivers/virtio/virtio_net.c      | 3 +--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/uknetdev/include/uk/netdev_core.h 
b/lib/uknetdev/include/uk/netdev_core.h
index e7fa97f2..df6ceebf 100644
--- a/lib/uknetdev/include/uk/netdev_core.h
+++ b/lib/uknetdev/include/uk/netdev_core.h
@@ -147,6 +147,7 @@ struct uk_netdev_info {
        uint16_t max_mtu;   /**< Maximum supported MTU size. */
        uint16_t nb_encap_tx;  /**< Number of bytes required as headroom for 
tx. */
        uint16_t nb_encap_rx;  /**< Number of bytes required as headroom for 
rx. */
+       uint16_t ioalign;  /**< Alignment in bytes for packet data buffers */
        uint32_t features; /**< bitmap of the features supported */
 };
 
@@ -156,8 +157,8 @@ struct uk_netdev_info {
 struct uk_netdev_queue_info {
        uint16_t nb_max;        /**< Max allowed number of descriptors. */
        uint16_t nb_min;        /**< Min allowed number of descriptors. */
-       uint16_t nb_align;      /**< Number should be a multiple of nb_align. */
-       int nb_is_power_of_two; /**< Number should be a power of two. */
+       uint16_t nb_align;      /**< Number of descriptors should be aligned. */
+       int nb_is_power_of_two; /**< Number of descriptors should be a power of 
two. */
 };
 
 /**
diff --git a/plat/drivers/virtio/virtio_net.c b/plat/drivers/virtio/virtio_net.c
index 9930859a..b5979d1e 100644
--- a/plat/drivers/virtio/virtio_net.c
+++ b/plat/drivers/virtio/virtio_net.c
@@ -770,7 +770,6 @@ static int virtio_netdev_rxq_info_get(struct uk_netdev *dev,
        rxq = &vndev->rxqs[queue_id];
        qinfo->nb_min = 1;
        qinfo->nb_max = rxq->max_nb_desc;
-       qinfo->nb_align = sizeof(void *); /* word size alignment */
        qinfo->nb_is_power_of_two = 1;
 
 exit:
@@ -798,7 +797,6 @@ static int virtio_netdev_txq_info_get(struct uk_netdev *dev,
        txq = &vndev->txqs[queue_id];
        qinfo->nb_min = 1;
        qinfo->nb_max = txq->max_nb_desc;
-       qinfo->nb_align = sizeof(void *); /* word size alignment */
        qinfo->nb_is_power_of_two = 1;
 
 exit:
@@ -1053,6 +1051,7 @@ static void virtio_net_info_get(struct uk_netdev *dev,
        dev_info->max_mtu = vndev->max_mtu;
        dev_info->nb_encap_tx = sizeof(struct virtio_net_hdr_padded);
        dev_info->nb_encap_rx = sizeof(struct virtio_net_hdr_padded);
+       dev_info->ioalign = sizeof(void *); /* word size alignment */
        dev_info->features = UK_FEATURE_RXQ_INTR_AVAILABLE;
 }
 
-- 
2.20.1