From mboxrd@z Thu Jan  1 00:00:00 1970
From: Avi Kivity <avi@qumranet.com>
Subject: Re: minor device number request for /dev/kvm (kernel-based virtual
 machine)
Date: Thu, 01 Mar 2007 13:58:08 +0200
Message-ID: <45E6BFD0.1060003@qumranet.com>
References: <45975F61.4070506@qumranet.com> <93C4769E3BED6B42B7203BD6F065654C08C5D6D3@dmoexc01.emea.cpqcorp.net>
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Cc: linux-kernel <linux-kernel@vger.kernel.org>,
	kvm-devel <kvm-devel@lists.sourceforge.net>
To: "Mathiasen, Torben" <Torben.Mathiasen@hp.com>
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Mathiasen, Torben wrote:
>>  10 char        Non-serial mice, misc features
>>     nnn = /dev/kvm  kernel-based virtual machine (hardware
>> virtualization extensions)
>>
>>     
>
> Major 10, minor 256 has been assigned to /dev/kvm. Let me know if this is nok okay.
>
>   

It doesn't work.  The culprit appears to be

drivers/char/misc.c:

    register_chrdev(MISC_MAJOR,"misc",&misc_fops)


which in turn means:


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.

-- 
error compiling committee.c: too many arguments to function