Re: [PATCHv2 for-4.6] p2m/ept: Work around hardware errata setting A bit

[George Dunlap <george.dunlap@citrix.com>]

On 28/09/15 15:09, Jan Beulich wrote:
>>>> On 28.09.15 at 14:39, <ross.lagerwall@citrix.com> wrote:
>> --- a/xen/arch/x86/mm/p2m-ept.c
>> +++ b/xen/arch/x86/mm/p2m-ept.c
>> @@ -34,6 +34,8 @@
>>  
>>  #include "mm-locks.h"
>>  
>> +static bool_t __read_mostly cpu_has_ept_ad;
> 
> This should be
> #define cpu_has_ept_ad (vmx_ept_vpid_cap & VMX_EPT_AD_BIT)
> put next to the respective other ones in vmx.h.
> 
>> @@ -1150,6 +1152,9 @@ int ept_p2m_init(struct p2m_domain *p2m)
>>      p2m->memory_type_changed = ept_memory_type_changed;
>>      p2m->audit_p2m = NULL;
>>  
>> +    /* Work around Errata AVR41 on Avaton processors. */
>> +    cpu_has_ept_ad = boot_cpu_data.x86_model != 0x4d;
> 
> And this one then should turn off said flag (i.e. needs to be moved
> elsewhere).
> 
> Plus PML initialization should get a respective check added.

In case there was any doubt, I am following this thread, and so far
haven't had anything to disagree with the direction Tim and Jan are
suggesting.

 -George