From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Cooper <andrew.cooper3@citrix.com>
Subject: Re: [RFC PATCH 03/10] Add cpuid_vmware_leaves
Date: Fri, 13 Dec 2013 13:38:39 +0000
Message-ID: <52AB0DDF.9050008@citrix.com>
References: <1386875718-28166-1-git-send-email-dslutz@terremark.com>
	<1386875718-28166-4-git-send-email-dslutz@terremark.com>
	<52AA383B.8000105@citrix.com>
	<52AAF59C020000780010CEC9@nat28.tlf.novell.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xen.org>
Received: from mail6.bemta5.messagelabs.com ([195.245.231.135])
	by lists.xen.org with esmtp (Exim 4.72)
	(envelope-from <Andrew.Cooper3@citrix.com>) id 1VrSxK-000206-43
	for xen-devel@lists.xenproject.org; Fri, 13 Dec 2013 13:39:05 +0000
In-Reply-To: <52AAF59C020000780010CEC9@nat28.tlf.novell.com>
List-Unsubscribe: <http://lists.xen.org/cgi-bin/mailman/options/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xen.org>
List-Help: <mailto:xen-devel-request@lists.xen.org?subject=help>
List-Subscribe: <http://lists.xen.org/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=subscribe>
Sender: xen-devel-bounces@lists.xen.org
Errors-To: xen-devel-bounces@lists.xen.org
To: Jan Beulich <JBeulich@suse.com>, Don Slutz <dslutz@verizon.com>
Cc: Keir Fraser <keir@xen.org>, Ian Campbell <ian.campbell@citrix.com>, Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Ian Jackson <ian.jackson@eu.citrix.com>, Eddie Dong <eddie.dong@intel.com>, Jun Nakajima <jun.nakajima@intel.com>, xen-devel <xen-devel@lists.xenproject.org>, Boris Ostrovsky <boris.ostrovsky@oracle.com>, Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
List-Id: xen-devel@lists.xenproject.org

On 13/12/2013 10:55, Jan Beulich wrote:
>>>> On 12.12.13 at 23:27, Andrew Cooper <andrew.cooper3@citrix.com> wrote:
>> On 12/12/2013 19:15, Don Slutz wrote:
>>>  int cpuid_hypervisor_leaves( uint32_t idx, uint32_t sub_idx,
>>>                 uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx)
>>>  {
>>>      struct domain *d = current->domain;
>>>      /* Optionally shift out of the way of Viridian architectural leaves. */
>>> -    uint32_t base = is_viridian_domain(d) ? 0x40000100 : 0x40000000;
>>> +    uint32_t base = 0x40000000;
>>>      uint32_t limit;
>>>  
>>> +    if ( is_viridian_domain(d) )
>>> +        base += 0x100;
>>> +    if ( is_vmware_domain(d) )
>>> +        base += 0x100;
>>> +
>> These bases need a far more scalable solution, especially as the result
>> of each of these clauses can be changed at runtime with a cunning
>> hvm_param_set hypercall.
>>
>> I think that both "is pretending to be HyperV" and "is pretending to be
>> VMware" need to be domain creation flags which are strictly static for
>> the lifetime of the domain.
> And it seems highly questionable to me whether having both at the
> same time makes much sense.
>
> Plus the new function doesn't belong in xen/arch/x86/traps.c ...
>
> Jan
>

I would certainly agree on the sentiment of it not making much sense.

However, as Xen needs viridian to run windows, I would be astounded if
vmware VMs didn't have viridian as well, in which case it is probably
quite likely that a vmware windows vm with vmware tools would expect to
find viridian and vmware extensions.

~Andrew