Commit a9289282 authored by Rusty Russell's avatar Rusty Russell
Browse files

virtio: expose features in sysfs 



Each device negotiates feature bits; expose these in sysfs to help
diagnostics and debugging.

Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 82af8ce8

drivers/virtio/virtio.c

+16 −0
Original line number Diff line number Diff line
@@ -31,11 +31,27 @@ static ssize_t modalias_show(struct device *_d, 
	return sprintf(buf, "virtio:d%08Xv%08X\n",

		       dev->id.device, dev->id.vendor);

}

static ssize_t features_show(struct device *_d,

			     struct device_attribute *attr, char *buf)

{

	struct virtio_device *dev = container_of(_d, struct virtio_device, dev);

	unsigned int i;

	ssize_t len = 0;



	/* We actually represent this as a bitstring, as it could be

	 * arbitrary length in future. */

	for (i = 0; i < ARRAY_SIZE(dev->features)*BITS_PER_LONG; i++)

		len += sprintf(buf+len, "%c",

			       test_bit(i, dev->features) ? '1' : '0');

	len += sprintf(buf+len, "\n");

	return len;

}

static struct device_attribute virtio_dev_attrs[] = {

	__ATTR_RO(device),

	__ATTR_RO(vendor),

	__ATTR_RO(status),

	__ATTR_RO(modalias),

	__ATTR_RO(features),

	__ATTR_NULL

};