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, 3 insertions, 8 deletions

diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 35eeb2a1bada..ff454a0ec6f5 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -105,6 +105,7 @@ struct vhost_virtqueue {
         struct vring_used_elem *heads;
         /* Protected by virtqueue mutex. */
         void *private_data;
+        unsigned acked_features;
         /* Log write descriptors */
         void __user *log_base;
         struct vhost_log *log;
@@ -117,7 +118,6 @@ struct vhost_dev {
         struct vhost_memory __rcu *memory;
         struct mm_struct *mm;
         struct mutex mutex;
-        unsigned acked_features;
         struct vhost_virtqueue **vqs;
         int nvqs;
         struct file *log_file;
@@ -174,13 +174,8 @@ enum {
                          (1ULL << VHOST_F_LOG_ALL),
 };
 
-static inline int vhost_has_feature(struct vhost_dev *dev, int bit)
+static inline int vhost_has_feature(struct vhost_virtqueue *vq, int bit)
 {
-        unsigned acked_features;
-
-        /* TODO: check that we are running from vhost_worker or dev mutex is
-         * held? */
-        acked_features = rcu_dereference_index_check(dev->acked_features, 1);
-        return acked_features & (1 << bit);
+        return vq->acked_features & (1 << bit);
 }
 #endif