Skip to content

Commit

Permalink
vhost: add notification for packed ring
Browse files Browse the repository at this point in the history 
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Tiwei Bie <tiwei.bie@intel.com>
  • Loading branch information
@mcoquelin @tmonjalo
mcoquelin authored and tmonjalo committed Jul 10, 2018
1 parent ae999ce commit b1cce26
Show file tree
Hide file tree
Showing 4 changed files with 162 additions and 18 deletions.
71 changes: 62 additions & 9 deletions lib/librte_vhost/vhost.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
}

Expand Down Expand Up @@ -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;

Expand Down Expand Up @@ -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;
}

Expand All @@ -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;
}

Expand Down
73 changes: 70 additions & 3 deletions lib/librte_vhost/vhost.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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)

Expand Down Expand Up @@ -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

/*
Expand Down Expand Up @@ -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();
Expand All @@ -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_ */
24 changes: 24 additions & 0 deletions lib/librte_vhost/vhost_user.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
}

Expand Down
12 changes: 6 additions & 6 deletions lib/librte_vhost/virtio_net.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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)]);
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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__);
Expand Down Expand Up @@ -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;
Expand Down

0 comments on commit b1cce26

Please sign in to comment.