[dpdk-dev] [PATCH v2 1/2] vhost: add packed ring support to vring base requests

[Maxime Coquelin]

For packed ring layout, we need save and restore avail and
used indexes, and their wrap counter values.
Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
---
 lib/librte_vhost/vhost_user.c | 41 ++++++++++++++++++++++++++++++-----
 1 file changed, 35 insertions(+), 6 deletions(-)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 508228a3c..c712c9a40 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -696,10 +696,24 @@ vhost_user_set_vring_base(struct virtio_net **pdev,
                        int main_fd __rte_unused)
 {
        struct virtio_net *dev = *pdev;
-       dev->virtqueue[msg->payload.state.index]->last_used_idx  =
-                       msg->payload.state.num;
-       dev->virtqueue[msg->payload.state.index]->last_avail_idx =
-                       msg->payload.state.num;
+       struct vhost_virtqueue *vq = dev->virtqueue[msg->payload.state.index];
+       uint64_t val = msg->payload.state.num;
+
+       if (vq_is_packed(dev)) {
+               /*
+                * Bit[0:14]: avail index
+                * Bit[15]: avail wrap counter
+                * Bit[16:30]: used index
+                * Bit[31]: used wrap counter
+                */
+               vq->last_avail_idx = (val & 0x1f);
+               vq->avail_wrap_counter = (val & (0x1 << 15) >> 15);
+               vq->last_used_idx = (val & (0x1f << 16)) >> 16;
+               vq->used_wrap_counter = (val & (0x1 << 31) >> 31);
+       } else {
+               vq->last_used_idx = msg->payload.state.num;
+               vq->last_avail_idx = msg->payload.state.num;
+       }
 
        return VH_RESULT_OK;
 }
@@ -1208,6 +1222,7 @@ vhost_user_get_vring_base(struct virtio_net **pdev,
 {
        struct virtio_net *dev = *pdev;
        struct vhost_virtqueue *vq = dev->virtqueue[msg->payload.state.index];
+       uint64_t val;
 
        /* We have to stop the queue (virtio) if it is running. */
        vhost_destroy_device_notify(dev);
@@ -1215,8 +1230,22 @@ vhost_user_get_vring_base(struct virtio_net **pdev,
        dev->flags &= ~VIRTIO_DEV_READY;
        dev->flags &= ~VIRTIO_DEV_VDPA_CONFIGURED;
 
-       /* Here we are safe to get the last avail index */
-       msg->payload.state.num = vq->last_avail_idx;
+       /* Here we are safe to get the indexes */
+       if (vq_is_packed(dev)) {
+               /*
+                * Bit[0:14]: avail index
+                * Bit[15]: avail wrap counter
+                * Bit[16:30]: used index
+                * Bit[31]: used wrap counter
+                */
+               val = vq->last_avail_idx & 0x1f;
+               val |= vq->avail_wrap_counter << 15;
+               val |= (vq->last_used_idx & 0x1f) << 16;
+               val |= vq->used_wrap_counter << 31;
+               msg->payload.state.num = val;
+       } else {
+               msg->payload.state.num = vq->last_avail_idx;
+       }
 
        RTE_LOG(INFO, VHOST_CONFIG,
                "vring base idx:%d file:%d\n", msg->payload.state.index,
-- 
2.17.1