virtio: expose features in sysfs

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

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Rusty Russell 2009-06-12 22:16:37 -06:00
parent 82af8ce84e
commit a92892825a

View file

@ -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
};