From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Cooper <andrew.cooper3@citrix.com>
Subject: Re: [PATCH v2 11/12] x86/altp2m: Add altp2mhvm HVM
	domain parameter.
Date: Wed, 24 Jun 2015 19:08:47 +0100
Message-ID: <558AF22F.3050206@citrix.com>
References: <1434999372-3688-1-git-send-email-edmund.h.white@intel.com>
	<1434999372-3688-12-git-send-email-edmund.h.white@intel.com>
	<558AE1FC020000780008903C@mail.emea.novell.com>
	<558AEF9E.9090505@intel.com>
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To: Ed White <edmund.h.white@intel.com>, Jan Beulich <JBeulich@suse.com>
Cc: Ravi Sahita <ravi.sahita@intel.com>, Wei Liu <wei.liu2@citrix.com>, Tim Deegan <tim@xen.org>, Ian Jackson <ian.jackson@eu.citrix.com>, xen-devel@lists.xen.org, tlengyel@novetta.com, Daniel De Graaf <dgdegra@tycho.nsa.gov>
List-Id: xen-devel@lists.xenproject.org

On 24/06/15 18:57, Ed White wrote:
> On 06/24/2015 07:59 AM, Jan Beulich wrote:
>>>>> On 22.06.15 at 20:56, <edmund.h.white@intel.com> wrote:
>>> +    case HVM_PARAM_ALTP2MHVM:
>>> +        if ( a.value > 1 )
>>> +            rc = -EINVAL;
>>> +        if ( a.value &&
>>> +             d->arch.hvm_domain.params[HVM_PARAM_NESTEDHVM] )
>>> +            rc = -EINVAL;
>>> +        break;
>> As you added the new param to the change-once section of
>> hvm_allow_set_param() - what is this code good for?
> I don't understand. How does change-once invalidate this code?

I don't believe it does.  This code (appears to) enforce the param being
a boolean, and exclusive against HVM_PARAM_NESTEDHVM.

~Andrew