Re: [PATCH RFC v2] pvh: clearly specify used parameters in vcpu_guest_context

["Roger Pau Monné" <roger.pau@citrix.com>]

On 19/11/13 11:34, George Dunlap wrote:
> On 11/18/2013 06:18 PM, Roger Pau Monne wrote:
>>       if ( has_hvm_container_vcpu(v) )
>>       {
>> -        /*
>> -         * NB: TF_kernel_mode is set unconditionally for HVM guests,
>> -         * so we always use the gs_base_kernel here. If we change this
>> -         * function to imitate the PV functionality, we'll need to
>> -         * make it pay attention to the kernel bit.
>> -         */
>> -        hvm_set_info_guest(v, compat ? 0 : c.nat->gs_base_kernel);
> 
> I think we still need to call hvm_set_info_guest() here -- there is
> other stuff being set up, and it was called (without the extra argument
> for gs_base_kernel) before the PVH patch series went in.
> 
> (See c/s 35b1e07.)

I see, I will restore the hvm_set_info_guest call, good catch.

> 
>>
>>           if ( is_hvm_vcpu(v) || v->is_initialised )
>>               goto out;
>>
>> +        if ( c.nat->ctrlreg[0] ) {
>> +            v->arch.hvm_vcpu.guest_cr[0] |= c.nat->ctrlreg[0];
>> +            hvm_update_guest_cr(v, 0);
>> +        }
>> +
>> +        if ( c.nat->ctrlreg[4] ) {
>> +            v->arch.hvm_vcpu.guest_cr[4] |= c.nat->ctrlreg[4];
>> +            hvm_update_guest_cr(v, 4);
>> +        }
> 
> I thought the idea was that he would set cr0, cr3, and cr4 for all HVM
> guests, rather than special-casing PVH guests?

Well, I was just trying to make the PVH AP bringup interface stable,
without messing much with HVM (not that we shouldn't aim to do it for
HVM guests also), but I think the main concern now is releasing 4.4 with
a stable interface for PVH guests.

Thanks, Roger.