Re: [PATCH 5/9] x86/pvh: Set PVH guest's mode in XEN_DOMCTL_set_address_size

From: "Jan Beulich" <JBeulich@suse.com>
To: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: elena.ufimtseva@oracle.com, tim@xen.org,
	Kevin Tian <kevin.tian@intel.com>, Keir Fraser <keir@xen.org>,
	Andrew Cooper <andrew.cooper3@citrix.com>,
	Eddie Dong <eddie.dong@intel.com>,
	xen-devel@lists.xen.org, Jun Nakajima <jun.nakajima@intel.com>,
	roger.pau@citrix.com
Subject: Re: [PATCH 5/9] x86/pvh: Set PVH guest's mode in XEN_DOMCTL_set_address_size
Date: Wed, 24 Jun 2015 08:57:31 +0100	[thread overview]
Message-ID: <558A7F0B0200007800088B52@mail.emea.novell.com> (raw)
In-Reply-To: <558A1BA1.9060600@oracle.com>

>>> On 24.06.15 at 04:53, <boris.ostrovsky@oracle.com> wrote:
> On 06/23/2015 09:22 AM, Jan Beulich wrote:
>>
>>> --- a/xen/arch/x86/hvm/hvm.c
>>> +++ b/xen/arch/x86/hvm/hvm.c
>>> @@ -2320,12 +2320,7 @@ int hvm_vcpu_initialise(struct vcpu *v)
>>>       v->arch.hvm_vcpu.inject_trap.vector = -1;
>>>   
>>>       if ( is_pvh_domain(d) )
>>> -    {
>>> -        v->arch.hvm_vcpu.hcall_64bit = 1;    /* PVH 32bitfixme. */
>>> -        /* This is for hvm_long_mode_enabled(v). */
>>> -        v->arch.hvm_vcpu.guest_efer = EFER_LMA | EFER_LME;
>>>           return 0;
>>> -    }
>> With this removed, is there any guarantee that hvm_set_mode()
>> will be called for each vCPU?
> 
> IIUIC, toolstack is required to call XEN_DOMCTL_set_address_size which 
> results in a call to switch_compat/native(), which loop over all VCPUs, 
> calling set_mode.

I don't recall this being a strict requirement. I think a PV 64-bit
guest would start fine without.

Jan