vhost: move acked_features to VQs

Refactor code to make sure features are only accessed
under VQ mutex. This makes everything simpler, no need
for RCU here anymore.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 6 insertions, 3 deletions

diff --git a/drivers/vhost/test.c b/drivers/vhost/test.c
index c2a54fbf7f99..6fa3bf8bdec7 100644
--- a/drivers/vhost/test.c
+++ b/drivers/vhost/test.c
@@ -241,15 +241,18 @@ done:
 
 static int vhost_test_set_features(struct vhost_test *n, u64 features)
 {
+        struct vhost_virtqueue *vq;
+
         mutex_lock(&n->dev.mutex);
         if ((features & (1 << VHOST_F_LOG_ALL)) &&
             !vhost_log_access_ok(&n->dev)) {
                 mutex_unlock(&n->dev.mutex);
                 return -EFAULT;
         }
-        n->dev.acked_features = features;
-        smp_wmb();
-        vhost_test_flush(n);
+        vq = &n->vqs[VHOST_TEST_VQ];
+        mutex_lock(&vq->mutex);
+        vq->acked_features = features;
+        mutex_unlock(&vq->mutex);
         mutex_unlock(&n->dev.mutex);
         return 0;
 }