vhost: fix default value of kickfd and callfd

Currently, default values of kickfd and callfd are -1.
If the values are -1, current code guesses kickfd and callfd haven't
been initialized yet. Then vhost library will guess the virtqueue isn't
ready for processing.

But callfd and kickfd will be set as -1 when "--enable-kvm"
isn't specified in QEMU command line. It means we cannot treat -1 as
uninitialized state.

The patch defines -1 and -2 as VIRTIO_INVALID_EVENTFD and
VIRTIO_UNINITIALIZED_EVENTFD, and uses VIRTIO_UNINITIALIZED_EVENTFD for
the default values of kickfd and callfd.

Signed-off-by: Tetsuya Mukawa <mukawa@igel.co.jp>
Acked-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>

diff --git a/lib/librte_vhost/rte_virtio_net.h b/lib/librte_vhost/rte_virtio_net.h
index 443245d..600b20b 100644 (file)
--- a/lib/librte_vhost/rte_virtio_net.h
+++ b/lib/librte_vhost/rte_virtio_net.h
@@ -89,6 +89,8 @@ struct vhost_virtqueue {
        uint16_t                vhost_hlen;             /**< Vhost header length (varies depending on RX merge buffers. */
        volatile uint16_t       last_used_idx;          /**< Last index used on the available ring */
        volatile uint16_t       last_used_idx_res;      /**< Used for multiple devices reserving buffers. */
+#define VIRTIO_INVALID_EVENTFD         (-1)
+#define VIRTIO_UNINITIALIZED_EVENTFD   (-2)
        int                     callfd;                 /**< Used to notify the guest (trigger interrupt). */
        int                     kickfd;                 /**< Currently unused as polling mode is enabled. */
        int                     enabled;

diff --git a/lib/librte_vhost/vhost_rxtx.c b/lib/librte_vhost/vhost_rxtx.c
index ca939d6..a6330f8 100644 (file)
--- a/lib/librte_vhost/vhost_rxtx.c
+++ b/lib/librte_vhost/vhost_rxtx.c
@@ -333,7 +333,8 @@ virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
        rte_mb();
 
        /* Kick the guest if necessary. */
-       if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT))
+       if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
+                       && (vq->callfd >= 0))
                eventfd_write(vq->callfd, (eventfd_t)1);
        return count;
 }
@@ -586,7 +587,8 @@ virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
                rte_mb();
 
                /* Kick the guest if necessary. */
-               if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT))
+               if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
+                               && (vq->callfd >= 0))
                        eventfd_write(vq->callfd, (eventfd_t)1);
        }
 
@@ -929,7 +931,8 @@ rte_vhost_dequeue_burst(struct virtio_net *dev, uint16_t queue_id,
                        sizeof(vq->used->idx));
 
        /* Kick guest if required. */
-       if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT))
+       if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
+                       && (vq->callfd >= 0))
                eventfd_write(vq->callfd, (eventfd_t)1);
 
 out:

diff --git a/lib/librte_vhost/vhost_user/virtio-net-user.c b/lib/librte_vhost/vhost_user/virtio-net-user.c
index 65b5652..f5248bc 100644 (file)
--- a/lib/librte_vhost/vhost_user/virtio-net-user.c
+++ b/lib/librte_vhost/vhost_user/virtio-net-user.c
@@ -225,8 +225,8 @@ static int
 vq_is_ready(struct vhost_virtqueue *vq)
 {
        return vq && vq->desc   &&
-              vq->kickfd != -1 &&
-              vq->callfd != -1;
+              vq->kickfd != VIRTIO_UNINITIALIZED_EVENTFD &&
+              vq->callfd != VIRTIO_UNINITIALIZED_EVENTFD;
 }
 
 static int
@@ -258,7 +258,7 @@ user_set_vring_call(struct vhost_device_ctx ctx, struct VhostUserMsg *pmsg)
 
        file.index = pmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
        if (pmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK)
-               file.fd = -1;
+               file.fd = VIRTIO_INVALID_EVENTFD;
        else
                file.fd = pmsg->fds[0];
        RTE_LOG(INFO, VHOST_CONFIG,
@@ -279,7 +279,7 @@ user_set_vring_kick(struct vhost_device_ctx ctx, struct VhostUserMsg *pmsg)
 
        file.index = pmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
        if (pmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK)
-               file.fd = -1;
+               file.fd = VIRTIO_INVALID_EVENTFD;
        else
                file.fd = pmsg->fds[0];
        RTE_LOG(INFO, VHOST_CONFIG,
@@ -316,10 +316,10 @@ user_get_vring_base(struct vhost_device_ctx ctx,
         * sent and only sent in vhost_vring_stop.
         * TODO: cleanup the vring, it isn't usable since here.
         */
-       if (dev->virtqueue[state->index]->kickfd >= 0) {
+       if (dev->virtqueue[state->index]->kickfd >= 0)
                close(dev->virtqueue[state->index]->kickfd);
-               dev->virtqueue[state->index]->kickfd = -1;
-       }
+
+       dev->virtqueue[state->index]->kickfd = VIRTIO_UNINITIALIZED_EVENTFD;
 
        return 0;
 }

diff --git a/lib/librte_vhost/virtio-net.c b/lib/librte_vhost/virtio-net.c
index 28c3912..90da9ba 100644 (file)
--- a/lib/librte_vhost/virtio-net.c
+++ b/lib/librte_vhost/virtio-net.c
@@ -167,8 +167,8 @@ init_vring_queue(struct vhost_virtqueue *vq, int qp_idx)
 {
        memset(vq, 0, sizeof(struct vhost_virtqueue));
 
-       vq->kickfd = -1;
-       vq->callfd = -1;
+       vq->kickfd = VIRTIO_UNINITIALIZED_EVENTFD;
+       vq->callfd = VIRTIO_UNINITIALIZED_EVENTFD;
 
        /* Backends are set to -1 indicating an inactive device. */
        vq->backend = -1;