On Wed, Nov 19, 2025 at 12:04:12PM +0100, Paolo Abeni wrote:

On 11/19/25 7:55 AM, Michael S. Tsirkin wrote:

quoted

@@ -1720,6 +1720,7 @@ static long vhost_net_set_owner(struct vhost_net *n)
 static long vhost_net_ioctl(struct file *f, unsigned int ioctl,
 			    unsigned long arg)
 {
+	const DEFINE_VHOST_FEATURES_ARRAY(features_array, vhost_net_features);

I'm sorry for the late feedback, I was drowning in other stuff.

I have just a couple of non blocking suggestions, feel free to ignore.

Oh this is really nice.
I did exactly this and the diff is smaller while the compiler
was smart enough to figure it out and the generated code is the same.

Thanks!

I think that if you rename `vhost_net_features` as
`vhost_net_features_bits` and `features_array` as `vhost_net_features`
the diffstat could be smaller and possibly clearer.

quoted

 	u64 all_features[VIRTIO_FEATURES_U64S];
 	struct vhost_net *n = f->private_data;
 	void __user *argp = (void __user *)arg;

@@ -1734,14 +1735,14 @@ static long vhost_net_ioctl(struct file *f, unsigned int ioctl,
 			return -EFAULT;
 		return vhost_net_set_backend(n, backend.index, backend.fd);
 	case VHOST_GET_FEATURES:
-		features = vhost_net_features[0];
+		features = VHOST_FEATURES_U64(vhost_net_features, 0);

Here and below you could use directly:

		features = features_array[0];

if you apply the rename mentioned above, this chunk and the following 3
should not be needed.

[...]> diff --git a/drivers/vhost/test.c b/drivers/vhost/test.c

quoted

index 42c955a5b211..af727fccfe40 100644

--- a/drivers/vhost/test.c
+++ b/drivers/vhost/test.c

@@ -308,6 +308,12 @@ static long vhost_test_set_backend(struct vhost_test *n, unsigned index, int fd)
 	return r;
 }
 
+static const int vhost_test_features[] = {
+	VHOST_FEATURES
+};
+
+#define VHOST_TEST_FEATURES VHOST_FEATURES_U64(vhost_test_features, 0)

If you rename `VHOST_FEATURES` to `VHOST_FEATURES_BITS` and
`VHOST_TEST_FEATURES` to `VHOST_FEATURES`, the following two chunks
should not be needed.

Thanks,

Paolo