Re: [PATCH] xen: disable reporting hw virtualized lapic availability on PVH guests

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

On 04/06/14 12:45, Jan Beulich wrote:
>>>> On 04.06.14 at 12:12, <roger.pau@citrix.com> wrote:
>> --- a/xen/arch/x86/hvm/vmx/vmx.c
>> +++ b/xen/arch/x86/hvm/vmx/vmx.c
>> @@ -1660,7 +1660,7 @@ void vmx_hypervisor_cpuid_leaf(uint32_t sub_idx,
>>                                 uint32_t *eax, uint32_t *ebx,
>>                                 uint32_t *ecx, uint32_t *edx)
>>  {
>> -    if ( sub_idx != 0 )
>> +    if ( sub_idx != 0 || is_pvh_vcpu(current) )
>>          return;
>>      if ( cpu_has_vmx_apic_reg_virt )
> 
> The addition would belong on this line imo (in the && !is_pvh form).

Then I would also have to add another is_pvh gate on the next if:

    if ( cpu_has_vmx_virtualize_x2apic_mode && cpu_has_vmx_apic_reg_virt &&
         cpu_has_vmx_virtual_intr_delivery && !is_pvh_vcpu(current) )
        *eax |= XEN_HVM_CPUID_X2APIC_VIRT;

IMHO it seems easier to gate it on the first if and just
return, although I understand it is more correct to gate
it on a feature by feature basis.

Roger.