[Minios-devel] [UNIKRAFT PATCH 05/12] plat/drivers: Create virtio-block queues

[Roxana Nicolescu <nicolescu.roxana1996@xxxxxxxxx>]

This patch allocates the queues used for communication with the device.
One queue is responsible for handling both requests and responses
to/from device.

Signed-off-by: Roxana Nicolescu <nicolescu.roxana1996@xxxxxxxxx>
---
 plat/drivers/virtio/virtio_blk.c | 72 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)

diff --git a/plat/drivers/virtio/virtio_blk.c b/plat/drivers/virtio/virtio_blk.c
index bda37866..3d8b7745 100644
--- a/plat/drivers/virtio/virtio_blk.c
+++ b/plat/drivers/virtio/virtio_blk.c
@@ -56,13 +56,75 @@ struct virtio_blk_device {
        __u16 uid;
        /* Virtio Device */
        struct virtio_dev *vdev;
+       /* List of all the virtqueue in the pci device */
+       struct virtqueue *vq;
        /* Nb of max_queues supported by device */
        __u16 max_vqueue_pairs;
+       /* This is used when the user has decided the nb_queues to use */
+       __u16    nb_queues;
+       /* List of queues */
+       struct   uk_blkdev_queue *qs;
 };
 
+struct uk_blkdev_queue {
+       /* The virtqueue reference */
+       struct virtqueue *vq;
+       /* The libukblkdev queue identifier */
+       /* It is also the virtqueue identifier */
+       uint16_t lqueue_id;
+       /* Allocator */
+       struct uk_alloc *a;
+       /* The nr. of descriptor limit */
+       uint16_t max_nb_desc;
+       /* Reference to virtio_blk_device  */
+       struct virtio_blk_device *vbd;
 };
 
 
+static int virtio_blkdev_queues_alloc(struct virtio_blk_device *vbdev,
+                                   const struct uk_blkdev_conf *conf)
+{
+       int rc = 0;
+       uint16_t i = 0;
+       int vq_avail = 0;
+       __u16 qdesc_size[conf->nb_queues];
+
+       if (conf->nb_queues > vbdev->max_vqueue_pairs) {
+               uk_pr_err("Queue number not supported: %"__PRIu16"\n",
+                               conf->nb_queues);
+               return -ENOTSUP;
+       }
+
+       vbdev->nb_queues = conf->nb_queues;
+       vq_avail = virtio_find_vqs(vbdev->vdev, conf->nb_queues, qdesc_size);
+       if (unlikely(vq_avail != conf->nb_queues)) {
+               uk_pr_err("Expected: %d queues, Found: %d queues\n",
+                               conf->nb_queues, vq_avail);
+               rc = -ENOMEM;
+               goto exit;
+       }
+
+       /**
+        * TODO:
+        * The virtio device management data structure are allocated using the
+        * allocator from the blkdev configuration. In the future it might be
+        * wiser to move it to the allocator of each individual queue. This
+        * would better considering NUMA support.
+        */
+       vbdev->qs = uk_calloc(a, conf->nb_queues, sizeof(*vbdev->qs));
+       if (unlikely(vbdev->qs == NULL)) {
+               uk_pr_err("Failed to allocate memory for queue management\n");
+               rc = -ENOMEM;
+               goto exit;
+       }
+
+       for (i = 0; i < conf->nb_queues; ++i)
+               vbdev->qs[i].max_nb_desc = qdesc_size[i];
+
+exit:
+       return rc;
+}
+
 static int virtio_blkdev_configure(struct uk_blkdev *dev,
                const struct uk_blkdev_conf *conf)
 {
@@ -73,8 +135,17 @@ static int virtio_blkdev_configure(struct uk_blkdev *dev,
        UK_ASSERT(conf != NULL);
 
        vbdev = to_virtioblkdev(dev);
+       rc = virtio_blkdev_queues_alloc(vbdev, conf);
+       if (rc) {
+               uk_pr_err("Failed to allocate the queues %d\n", rc);
+               goto exit;
+       }
 
        uk_pr_info(DRIVER_NAME": %"__PRIu16" configured\n", vbdev->uid);
+exit:
+       return rc;
+}
+
        return rc;
 }
 
@@ -87,6 +158,7 @@ static void virtio_blkdev_close(struct uk_blkdev *dev)
        d = to_virtioblkdev(dev);
        uid = d->uid;
        uk_blkdev_drv_unregister(dev, a);
+       uk_free(a, d->qs);
        uk_free(a, d);
 
        uk_pr_info(DRIVER_NAME": %"__PRIu16" closed\n", uid);
-- 
2.11.0


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