Re: KVM: x86: verify MTRR/PAT validity

[Avi Kivity <avi@redhat.com>]

On 06/16/2009 03:05 PM, Marcelo Tosatti wrote:
> Do not allow invalid MTRR/PAT values in set_msr_mtrr.
>
> Please review carefully.
>
> Signed-off-by: Marcelo Tosatti<mtosatti@redhat.com>
>
>
> +static unsigned mtrr_types[] = {0, 1, 4, 5, 6};
> +static unsigned pat_types[] = {0, 1, 4, 5, 6, 7};
> +
> +static bool valid_mt(unsigned type, int len, unsigned array[len])
> +{
> +	int i;
> +
> +	for (i = 0; i<  len; i++)
> +		if (type == array[i])
> +			return true;
> +
> +	return false;
> +}
> +
> +#define valid_pat_type(a) valid_mt(a, ARRAY_SIZE(pat_types), pat_types)
> +#define valid_mtrr_type(a) valid_mt(a, ARRAY_SIZE(mtrr_types), mtrr_types)
> +
>    

A little pointless since this is so performance-insensitive, but still:

valid_pat_type(t)
{
     return t < 8 && (1 << t) & 0xf3; /* 0, 1, 4, 5, 6, 7 */
}

valid_mtrr_type(t)
{
     return t < 8 && (1 << t) & 0x73; /* 0, 1, 4, 5, 6 */
}

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