vhost: add notification for packed ring

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Tiwei Bie <tiwei.bie@intel.com>

diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
index 534f30c..3c9be10 100644 (file)
--- a/lib/librte_vhost/vhost.c
+++ b/lib/librte_vhost/vhost.c
@@ -163,13 +163,28 @@ vring_translate_packed(struct virtio_net *dev, struct vhost_virtqueue *vq)
 
        req_size = sizeof(struct vring_packed_desc) * vq->size;
        size = req_size;
-       vq->desc_packed =
-               (struct vring_packed_desc *)(uintptr_t)vhost_iova_to_vva(dev,
-                                       vq, vq->ring_addrs.desc_user_addr,
-                                       &size, VHOST_ACCESS_RW);
+       vq->desc_packed = (struct vring_packed_desc *)(uintptr_t)
+               vhost_iova_to_vva(dev, vq, vq->ring_addrs.desc_user_addr,
+                               &size, VHOST_ACCESS_RW);
        if (!vq->desc_packed || size != req_size)
                return -1;
 
+       req_size = sizeof(struct vring_packed_desc_event);
+       size = req_size;
+       vq->driver_event = (struct vring_packed_desc_event *)(uintptr_t)
+               vhost_iova_to_vva(dev, vq, vq->ring_addrs.avail_user_addr,
+                               &size, VHOST_ACCESS_RW);
+       if (!vq->driver_event || size != req_size)
+               return -1;
+
+       req_size = sizeof(struct vring_packed_desc_event);
+       size = req_size;
+       vq->device_event = (struct vring_packed_desc_event *)(uintptr_t)
+               vhost_iova_to_vva(dev, vq, vq->ring_addrs.used_user_addr,
+                               &size, VHOST_ACCESS_RW);
+       if (!vq->device_event || size != req_size)
+               return -1;
+
        return 0;
 }
 
@@ -270,6 +285,7 @@ alloc_vring_queue(struct virtio_net *dev, uint32_t vring_idx)
        rte_spinlock_init(&vq->access_lock);
        vq->avail_wrap_counter = 1;
        vq->used_wrap_counter = 1;
+       vq->signalled_used_valid = false;
 
        dev->nr_vring += 1;
 
@@ -604,7 +620,11 @@ rte_vhost_vring_call(int vid, uint16_t vring_idx)
        if (!vq)
                return -1;
 
-       vhost_vring_call(dev, vq);
+       if (vq_is_packed(dev))
+               vhost_vring_call_packed(dev, vq);
+       else
+               vhost_vring_call_split(dev, vq);
+
        return 0;
 }
 
@@ -625,19 +645,52 @@ rte_vhost_avail_entries(int vid, uint16_t queue_id)
        return *(volatile uint16_t *)&vq->avail->idx - vq->last_used_idx;
 }
 
+static inline void
+vhost_enable_notify_split(struct vhost_virtqueue *vq, int enable)
+{
+       if (enable)
+               vq->used->flags &= ~VRING_USED_F_NO_NOTIFY;
+       else
+               vq->used->flags |= VRING_USED_F_NO_NOTIFY;
+}
+
+static inline void
+vhost_enable_notify_packed(struct virtio_net *dev,
+               struct vhost_virtqueue *vq, int enable)
+{
+       uint16_t flags;
+
+       if (!enable)
+               vq->device_event->flags = VRING_EVENT_F_DISABLE;
+
+       flags = VRING_EVENT_F_ENABLE;
+       if (dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX)) {
+               flags = VRING_EVENT_F_DESC;
+               vq->device_event->off_wrap = vq->last_avail_idx |
+                       vq->avail_wrap_counter << 15;
+       }
+
+       rte_smp_wmb();
+
+       vq->device_event->flags = flags;
+}
+
 int
 rte_vhost_enable_guest_notification(int vid, uint16_t queue_id, int enable)
 {
        struct virtio_net *dev = get_device(vid);
+       struct vhost_virtqueue *vq;
 
        if (!dev)
                return -1;
 
-       if (enable)
-               dev->virtqueue[queue_id]->used->flags &=
-                       ~VRING_USED_F_NO_NOTIFY;
+       vq = dev->virtqueue[queue_id];
+
+       if (vq_is_packed(dev))
+               vhost_enable_notify_packed(dev, vq, enable);
        else
-               dev->virtqueue[queue_id]->used->flags |= VRING_USED_F_NO_NOTIFY;
+               vhost_enable_notify_split(vq, enable);
+
        return 0;
 }
 

diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index a7e602b..760a09c 100644 (file)
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -95,14 +95,21 @@ struct vhost_virtqueue {
                struct vring_desc       *desc;
                struct vring_packed_desc   *desc_packed;
        };
-       struct vring_avail      *avail;
-       struct vring_used       *used;
+       union {
+               struct vring_avail      *avail;
+               struct vring_packed_desc_event *driver_event;
+       };
+       union {
+               struct vring_used       *used;
+               struct vring_packed_desc_event *device_event;
+       };
        uint32_t                size;
 
        uint16_t                last_avail_idx;
        uint16_t                last_used_idx;
        /* Last used index we notify to front end. */
        uint16_t                signalled_used;
+       bool                    signalled_used_valid;
 #define VIRTIO_INVALID_EVENTFD         (-1)
 #define VIRTIO_UNINITIALIZED_EVENTFD   (-2)
 
@@ -225,6 +232,15 @@ struct vring_packed_desc {
        uint16_t id;
        uint16_t flags;
 };
+
+#define VRING_EVENT_F_ENABLE 0x0
+#define VRING_EVENT_F_DISABLE 0x1
+#define VRING_EVENT_F_DESC 0x2
+
+struct vring_packed_desc_event {
+       uint16_t off_wrap;
+       uint16_t flags;
+};
 #endif
 
 /*
@@ -648,7 +664,7 @@ vhost_need_event(uint16_t event_idx, uint16_t new_idx, uint16_t old)
 }
 
 static __rte_always_inline void
-vhost_vring_call(struct virtio_net *dev, struct vhost_virtqueue *vq)
+vhost_vring_call_split(struct virtio_net *dev, struct vhost_virtqueue *vq)
 {
        /* Flush used->idx update before we read avail->flags. */
        rte_smp_mb();
@@ -675,4 +691,55 @@ vhost_vring_call(struct virtio_net *dev, struct vhost_virtqueue *vq)
        }
 }
 
+static __rte_always_inline void
+vhost_vring_call_packed(struct virtio_net *dev, struct vhost_virtqueue *vq)
+{
+       uint16_t old, new, off, off_wrap;
+       bool signalled_used_valid, kick = false;
+
+       /* Flush used desc update. */
+       rte_smp_mb();
+
+       if (!(dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX))) {
+               if (vq->driver_event->flags !=
+                               VRING_EVENT_F_DISABLE)
+                       kick = true;
+               goto kick;
+       }
+
+       old = vq->signalled_used;
+       new = vq->last_used_idx;
+       vq->signalled_used = new;
+       signalled_used_valid = vq->signalled_used_valid;
+       vq->signalled_used_valid = true;
+
+       if (vq->driver_event->flags != VRING_EVENT_F_DESC) {
+               if (vq->driver_event->flags != VRING_EVENT_F_DISABLE)
+                       kick = true;
+               goto kick;
+       }
+
+       if (unlikely(!signalled_used_valid)) {
+               kick = true;
+               goto kick;
+       }
+
+       rte_smp_rmb();
+
+       off_wrap = vq->driver_event->off_wrap;
+       off = off_wrap & ~(1 << 15);
+
+       if (new <= old)
+               old -= vq->size;
+
+       if (vq->used_wrap_counter != off_wrap >> 15)
+               off -= vq->size;
+
+       if (vhost_need_event(off, new, old))
+               kick = true;
+kick:
+       if (kick)
+               eventfd_write(vq->callfd, (eventfd_t)1);
+}
+
 #endif /* _VHOST_NET_CDEV_H_ */

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 92958b9..dc53ff7 100644 (file)
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -512,6 +512,30 @@ translate_ring_addresses(struct virtio_net *dev, int vq_index)
                vq = dev->virtqueue[vq_index];
                addr = &vq->ring_addrs;
 
+               len = sizeof(struct vring_packed_desc_event);
+               vq->driver_event = (struct vring_packed_desc_event *)
+                                       (uintptr_t)ring_addr_to_vva(dev,
+                                       vq, addr->avail_user_addr, &len);
+               if (vq->driver_event == NULL ||
+                               len != sizeof(struct vring_packed_desc_event)) {
+                       RTE_LOG(DEBUG, VHOST_CONFIG,
+                               "(%d) failed to find driver area address.\n",
+                               dev->vid);
+                       return dev;
+               }
+
+               len = sizeof(struct vring_packed_desc_event);
+               vq->device_event = (struct vring_packed_desc_event *)
+                                       (uintptr_t)ring_addr_to_vva(dev,
+                                       vq, addr->used_user_addr, &len);
+               if (vq->device_event == NULL ||
+                               len != sizeof(struct vring_packed_desc_event)) {
+                       RTE_LOG(DEBUG, VHOST_CONFIG,
+                               "(%d) failed to find device area address.\n",
+                               dev->vid);
+                       return dev;
+               }
+
                return dev;
        }
 

diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index 013a002..2b7ffcf 100644 (file)
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -826,7 +826,7 @@ virtio_dev_rx_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
 
        if (likely(vq->shadow_used_idx)) {
                flush_shadow_used_ring_split(dev, vq);
-               vhost_vring_call(dev, vq);
+               vhost_vring_call_split(dev, vq);
        }
 
        return pkt_idx;
@@ -879,7 +879,7 @@ virtio_dev_rx_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
 
        if (likely(vq->shadow_used_idx)) {
                flush_shadow_used_ring_packed(dev, vq);
-               vhost_vring_call(dev, vq);
+               vhost_vring_call_packed(dev, vq);
        }
 
        return pkt_idx;
@@ -1363,7 +1363,7 @@ virtio_dev_tx_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
                }
 
                flush_shadow_used_ring_split(dev, vq);
-               vhost_vring_call(dev, vq);
+               vhost_vring_call_split(dev, vq);
        }
 
        rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]);
@@ -1442,7 +1442,7 @@ virtio_dev_tx_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
                if (unlikely(i < count))
                        vq->shadow_used_idx = i;
                flush_shadow_used_ring_split(dev, vq);
-               vhost_vring_call(dev, vq);
+               vhost_vring_call_split(dev, vq);
        }
 
        return i;
@@ -1478,7 +1478,7 @@ virtio_dev_tx_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
                }
 
                flush_shadow_used_ring_packed(dev, vq);
-               vhost_vring_call(dev, vq);
+               vhost_vring_call_packed(dev, vq);
        }
 
        VHOST_LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
@@ -1556,7 +1556,7 @@ virtio_dev_tx_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
                if (unlikely(i < count))
                        vq->shadow_used_idx = i;
                flush_shadow_used_ring_packed(dev, vq);
-               vhost_vring_call(dev, vq);
+               vhost_vring_call_packed(dev, vq);
        }
 
        return i;