[Minios-devel] [UNIKRAFT PATCH v2 2/5] plat/drivers: Add 9P device initialization

[Vlad-Andrei BĂDOIU (78692) <vlad_andrei.badoiu@xxxxxxxxxxxxxxx>]

From: Cristian Banu <cristb@xxxxxxxxx>

This patch implements the 9P driver and device initialization.

Signed-off-by: Cristian Banu <cristb@xxxxxxxxx>
---
 plat/drivers/include/virtio/virtio_9p.h |   9 ++
 plat/drivers/virtio/virtio_9p.c         | 132 +++++++++++++++++++++++-
 2 files changed, 138 insertions(+), 3 deletions(-)

diff --git a/plat/drivers/include/virtio/virtio_9p.h 
b/plat/drivers/include/virtio/virtio_9p.h
index 5459a397..29158ab7 100644
--- a/plat/drivers/include/virtio/virtio_9p.h
+++ b/plat/drivers/include/virtio/virtio_9p.h
@@ -41,4 +41,13 @@
 #include <virtio/virtio_config.h>
 #include <virtio/virtio_types.h>
 
+/* Feature bitmap for virtio 9P. */
+#define VIRTIO_9P_F_MOUNT_TAG 0
+
+/* Virtio 9P PCI configuration space layout. */
+struct virtio_9p_config {
+       __u16 tag_len;
+       __u8 tag[0];
+} __packed;
+
 #endif /* __PLAT_DRV_VIRTIO_9P_H */
diff --git a/plat/drivers/virtio/virtio_9p.c b/plat/drivers/virtio/virtio_9p.c
index 855548fe..798ebe90 100644
--- a/plat/drivers/virtio/virtio_9p.c
+++ b/plat/drivers/virtio/virtio_9p.c
@@ -32,19 +32,145 @@
  * THIS HEADER MAY NOT BE EXTRACTED OR MODIFIED IN ANY WAY.
  */
 
+#include <uk/alloc.h>
+#include <uk/essentials.h>
 #include <virtio/virtio_bus.h>
 #include <virtio/virtio_9p.h>
+#include <uk/plat/spinlock.h>
 
-static int virtio_9p_add_dev(struct virtio_dev *vdev __unused)
+#define DRIVER_NAME    "virtio-9p"
+static struct uk_alloc *a;
+
+/* List of initialized virtio 9p devices. */
+static UK_LIST_HEAD(virtio_9p_device_list);
+static DEFINE_SPINLOCK(virtio_9p_device_list_lock);
+
+struct virtio_9p_device {
+       /* Virtio device. */
+       struct virtio_dev *vdev;
+       /* Mount tag for this virtio device. */
+       char *tag;
+       /* Entry within the virtio devices' list. */
+       struct uk_list_head _list;
+};
+
+static int virtio_9p_feature_negotiate(struct virtio_9p_device *d)
 {
-       return 0;
+       __u64 host_features;
+       __u16 tag_len;
+       int rc = 0;
+
+       host_features = virtio_feature_get(d->vdev);
+       if (!virtio_has_features(host_features, VIRTIO_9P_F_MOUNT_TAG)) {
+               uk_pr_err(DRIVER_NAME": Host system does not offer MOUNT_TAG 
feature\n");
+               rc = -EINVAL;
+               goto out;
+       }
+
+       virtio_config_get(d->vdev,
+                         __offsetof(struct virtio_9p_config, tag_len),
+                         &tag_len, 1, sizeof(tag_len));
+
+       d->tag = uk_calloc(a, tag_len + 1, sizeof(*d->tag));
+       if (!d->tag) {
+               rc = -ENOMEM;
+               goto out;
+       }
+
+       virtio_config_get(d->vdev,
+                         __offsetof(struct virtio_9p_config, tag),
+                         d->tag, tag_len, 1);
+       d->tag[tag_len] = '\0';
+
+       d->vdev->features &= host_features;
+       virtio_feature_set(d->vdev, d->vdev->features);
+
+out:
+       return rc;
+}
+
+static inline void virtio_9p_feature_set(struct virtio_9p_device *d)
+{
+       d->vdev->features = 0;
+       VIRTIO_FEATURES_UPDATE(d->vdev->features, VIRTIO_9P_F_MOUNT_TAG);
+}
+
+static int virtio_9p_configure(struct virtio_9p_device *d)
+{
+       int rc = 0;
+
+       rc = virtio_9p_feature_negotiate(d);
+       if (rc != 0) {
+               uk_pr_err(DRIVER_NAME": Failed to negotiate the device feature 
%d\n",
+                       rc);
+               rc = -EINVAL;
+               goto out_status_fail;
+       }
+
+       uk_pr_info(DRIVER_NAME": Configured: features=0x%lx tag=%s\n",
+                       d->vdev->features, d->tag);
+out:
+       return rc;
+
+out_status_fail:
+       virtio_dev_status_update(d->vdev, VIRTIO_CONFIG_STATUS_FAIL);
+       goto out;
 }
 
-static int virtio_9p_drv_init(struct uk_alloc *drv_allocator __unused)
+static int virtio_9p_start(struct virtio_9p_device *d)
 {
+       virtio_dev_drv_up(d->vdev);
+       uk_pr_info(DRIVER_NAME": %s started\n", d->tag);
+
        return 0;
 }
 
+static int virtio_9p_add_dev(struct virtio_dev *vdev)
+{
+       struct virtio_9p_device *d;
+       unsigned long flags;
+       int rc = 0;
+
+       UK_ASSERT(vdev != NULL);
+
+       d = uk_calloc(a, 1, sizeof(*d));
+       if (!d) {
+               rc = -ENOMEM;
+               goto out;
+       }
+       d->vdev = vdev;
+       virtio_9p_feature_set(d);
+       rc = virtio_9p_configure(d);
+       if (rc)
+               goto out_free;
+       rc = virtio_9p_start(d);
+       if (rc)
+               goto out_free;
+
+       ukplat_spin_lock_irqsave(&virtio_9p_device_list_lock, flags);
+       uk_list_add(&d->_list, &virtio_9p_device_list);
+       ukplat_spin_unlock_irqrestore(&virtio_9p_device_list_lock, flags);
+out:
+       return rc;
+out_free:
+       uk_free(a, d);
+       goto out;
+}
+
+static int virtio_9p_drv_init(struct uk_alloc *drv_allocator)
+{
+       int rc = 0;
+
+       if (!drv_allocator) {
+               rc = -EINVAL;
+               goto out;
+       }
+
+       a = drv_allocator;
+out:
+       return rc;
+}
+
 static const struct virtio_dev_id v9p_dev_id[] = {
        {VIRTIO_ID_9P},
        {VIRTIO_ID_INVALID} /* List Terminator */
-- 
2.20.1


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