[Minios-devel] [UNIKRAFT PATCH v2 02/12] lib/uknetdev: Add alignment for allocating packet buffers

[Costin Lupu <costin.lupu@xxxxxxxxx>]

On Xen, packet buffers have to be page aligned because they are saved in
page aligned memory regions which are shared between backend and
frontend by using grants.

Signed-off-by: Costin Lupu <costin.lupu@xxxxxxxxx>
---
 lib/uknetdev/include/uk/netdev_core.h | 1 +
 plat/drivers/virtio/virtio_net.c      | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/lib/uknetdev/include/uk/netdev_core.h 
b/lib/uknetdev/include/uk/netdev_core.h
index f073e101..268d54d7 100644
--- a/lib/uknetdev/include/uk/netdev_core.h
+++ b/lib/uknetdev/include/uk/netdev_core.h
@@ -94,6 +94,7 @@ 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 align;  /**< Alignment required for data address. */
 };
 
 /**
diff --git a/plat/drivers/virtio/virtio_net.c b/plat/drivers/virtio/virtio_net.c
index efc2cb71..9f1873c5 100644
--- a/plat/drivers/virtio/virtio_net.c
+++ b/plat/drivers/virtio/virtio_net.c
@@ -1048,8 +1048,10 @@ static void virtio_net_info_get(struct uk_netdev *dev,
 
        dev_info->max_rx_queues = vndev->max_vqueue_pairs;
        dev_info->max_tx_queues = vndev->max_vqueue_pairs;
+       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->align = sizeof(void *); /* word size alignment */
 }
 
 static int virtio_net_start(struct uk_netdev *n)
-- 
2.11.0


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