hw/virtio: Add support for VDPA network simulation devices

This patch adds support for VDPA network simulation devices.
The device is developed based on virtio-net and tap backend,
and supports hardware live migration function.

For more details, please refer to "docs/system/devices/vdpa-net.rst"

Signed-off-by: Hao Chen <chenh@yusur.tech>
Message-Id: <20240221073802.2888022-1-chenh@yusur.tech>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 39 insertions, 0 deletions

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index d229755eae..fb6b4ccd83 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -3368,6 +3368,18 @@ static uint16_t virtio_queue_split_get_last_avail_idx(VirtIODevice *vdev,
     return vdev->vq[n].last_avail_idx;
 }
 
+static uint32_t virtio_queue_split_get_vring_states(VirtIODevice *vdev,
+                                                      int n)
+{
+    struct VirtQueue *vq = &vdev->vq[n];
+    uint16_t avail, used;
+
+    avail = vq->last_avail_idx;
+    used = vq->used_idx;
+
+    return avail | (uint32_t)used << 16;
+}
+
 unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n)
 {
     if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
@@ -3377,6 +3389,33 @@ unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n)
     }
 }
 
+unsigned int virtio_queue_get_vring_states(VirtIODevice *vdev, int n)
+{
+    if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
+        return -1;
+    } else {
+        return virtio_queue_split_get_vring_states(vdev, n);
+    }
+}
+
+static void virtio_queue_split_set_vring_states(VirtIODevice *vdev,
+                                                int n, uint32_t idx)
+{
+    struct VirtQueue *vq = &vdev->vq[n];
+    vq->last_avail_idx = (uint16_t)(idx & 0xffff);
+    vq->shadow_avail_idx = (uint16_t)(idx & 0xffff);
+    vq->used_idx = (uint16_t)(idx >> 16);
+}
+
+void virtio_queue_set_vring_states(VirtIODevice *vdev, int n, uint32_t idx)
+{
+    if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
+        return;
+    } else {
+        virtio_queue_split_set_vring_states(vdev, n, idx);
+    }
+}
+
 static void virtio_queue_packed_set_last_avail_idx(VirtIODevice *vdev,
                                                    int n, unsigned int idx)
 {