1 files changed, 43 insertions, 9 deletions

diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 621a6d9a8791..4fe99765c5c7 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -14,6 +14,7 @@
 #include <linux/atomic.h>
 #include <linux/vhost_iotlb.h>
 #include <linux/irqbypass.h>
+#include <linux/unroll.h>
 
 struct vhost_work;
 struct vhost_task;
@@ -230,7 +231,15 @@ int vhost_get_vq_desc(struct vhost_virtqueue *,
 		      struct iovec iov[], unsigned int iov_size,
 		      unsigned int *out_num, unsigned int *in_num,
 		      struct vhost_log *log, unsigned int *log_num);
-void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
+
+int vhost_get_vq_desc_n(struct vhost_virtqueue *vq,
+			struct iovec iov[], unsigned int iov_size,
+			unsigned int *out_num, unsigned int *in_num,
+			struct vhost_log *log, unsigned int *log_num,
+			unsigned int *ndesc);
+
+void vhost_discard_vq_desc(struct vhost_virtqueue *, int nbuf,
+			   unsigned int ndesc);
 
 bool vhost_vq_work_queue(struct vhost_virtqueue *vq, struct vhost_work *work);
 bool vhost_vq_has_work(struct vhost_virtqueue *vq);
@@ -279,14 +288,39 @@ void vhost_iotlb_map_free(struct vhost_iotlb *iotlb,
 				eventfd_signal((vq)->error_ctx);\
 	} while (0)
 
-enum {
-	VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
-			 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
-			 (1ULL << VIRTIO_RING_F_EVENT_IDX) |
-			 (1ULL << VHOST_F_LOG_ALL) |
-			 (1ULL << VIRTIO_F_ANY_LAYOUT) |
-			 (1ULL << VIRTIO_F_VERSION_1)
-};
+#define VHOST_FEATURES \
+	VIRTIO_F_NOTIFY_ON_EMPTY, \
+	VIRTIO_RING_F_INDIRECT_DESC, \
+	VIRTIO_RING_F_EVENT_IDX, \
+	VHOST_F_LOG_ALL, \
+	VIRTIO_F_ANY_LAYOUT, \
+	VIRTIO_F_VERSION_1
+
+static inline u64 vhost_features_u64(const int *features, int size, int idx)
+{
+	u64 res = 0;
+
+	unrolled_count(VIRTIO_FEATURES_BITS)
+	for (int i = 0; i < size; ++i) {
+		int bit = features[i];
+
+		if (virtio_features_chk_bit(bit) && VIRTIO_U64(bit) == idx)
+			res |= VIRTIO_BIT(bit);
+	}
+	return res;
+}
+
+#define VHOST_FEATURES_U64(features, idx) \
+	vhost_features_u64(features, ARRAY_SIZE(features), idx)
+
+#define DEFINE_VHOST_FEATURES_ARRAY_ENTRY(idx, features) \
+	[idx] = VHOST_FEATURES_U64(features, idx),
+
+#define DEFINE_VHOST_FEATURES_ARRAY(array, features) \
+	u64 array[VIRTIO_FEATURES_U64S] = { \
+		UNROLL(VIRTIO_FEATURES_U64S, \
+		       DEFINE_VHOST_FEATURES_ARRAY_ENTRY, features) \
+	}
 
 /**
  * vhost_vq_set_backend - Set backend.