Re: [PATCH v2 12/12] x86/altp2m: XSM hooks for altp2m HVM ops

[Daniel De Graaf <dgdegra@tycho.nsa.gov>]

On 06/26/2015 03:35 PM, Ed White wrote:
> On 06/26/2015 12:24 PM, Daniel De Graaf wrote:
>> On 06/22/2015 02:56 PM, Ed White wrote:
>>> From: Ravi Sahita <ravi.sahita@intel.com>
>>>
>>> Signed-off-by: Ravi Sahita <ravi.sahita@intel.com>
>>
>> One comment, below.
>>
>> [...]
>>> diff --git a/tools/flask/policy/policy/modules/xen/xen.if b/tools/flask/policy/policy/modules/xen/xen.if
>>> index f4cde11..c95109f 100644
>>> --- a/tools/flask/policy/policy/modules/xen/xen.if
>>> +++ b/tools/flask/policy/policy/modules/xen/xen.if
>>> @@ -8,7 +8,7 @@
>>>    define(`declare_domain_common', `
>>>        allow $1 $2:grant { query setup };
>>>        allow $1 $2:mmu { adjust physmap map_read map_write stat pinpage updatemp mmuext_op };
>>> -    allow $1 $2:hvm { getparam setparam };
>>> +    allow $1 $2:hvm { getparam setparam altp2mhvm altp2mhvm_op };
>>>        allow $1 $2:domain2 get_vnumainfo;
>>>    ')
>>
>> This allows any domain to enable altp2m on itself; I think you meant to
>> only allow altp2mhvm_op here, requiring a privileged domain to first
>> enable the feature on a domain before anyone can use it.
>>
>
> We certainly don't want to unconditionally disallow that. We want the
> policy to offer the ability to choose whether it's allowed or not.
> Does the patch do that?

Remove altp2mhvm from the above line, leaving only altp2mhvm_op here.  The
other line added to xen.if should still contain both. This makes the FLASK
policy match the no-XSM case, which I assume is what you've tested.

-- 
Daniel De Graaf
National Security Agency