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Diffstat (limited to 'drivers/vhost/vhost.c')
| -rw-r--r-- | drivers/vhost/vhost.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 5c9c657ab75..750effe0f98 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1036,7 +1036,12 @@ int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len) /* This actually signals the guest, using eventfd. */ void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq) { - __u16 flags = 0; + __u16 flags; + /* Flush out used index updates. This is paired + * with the barrier that the Guest executes when enabling + * interrupts. */ + smp_mb(); + if (get_user(flags, &vq->avail->flags)) { vq_err(vq, "Failed to get flags"); return; |