Re: minor device number request for /dev/kvm (kernel-based virtualmachine)

[Jan Engelhardt]

On Mar 1 2007 13:58, Avi Kivity wrote:
>
> fs/char_dev.c:
>> int register_chrdev(unsigned int major, const char *name,
>>            const struct file_operations *fops)
>> {
>> struct char_device_struct *cd;
>> struct cdev *cdev;
>> char *s;
>> int err = -ENOMEM;
>> 
>> cd = __register_chrdev_region(major, 0, 256, name);
>
> So misc minor numbers under 256 are not supported.
>
> What's the way out?  Increase the region size?  I don't know if that's safe.

If it does not increase memory usage, then possibly:

  __register_chrdev_region(major, 0, (~0U) & MINORMASK, name);
                                  or (1<<MINORMASK)-1 if that's more clear


Jan
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