Re: [Xen-devel] [PATCH] x86/EPT: defer enabling of A/D maintenance until PML get enabled

[Kai Huang <kaih.linux@xxxxxxxxx>]

Good to me, if you have tested it. Sorry I cannot test it as I am
taking vacation  until Oct.8.

Thanks,
-Kai

On Mon, Sep 28, 2015 at 10:42 PM, Jan Beulich <JBeulich@xxxxxxxx> wrote:
> There's no point in enabling the extra feature for every domain when
> we're not meaning to use it (yet). Just setting the flag should be
> sufficient - the domain is required to be paused for PML enabling
> anyway, i.e. hardware will pick up the new setting the next time
> each vCPU of the guest gets scheduled.
>
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
> Cc: Kai Huang <kai.huang@xxxxxxxxxxxxxxx>
> ---
> VT-x maintainers, Kai: Me lacking the hardware to test this, may I ask
> for your help here?
>
> --- a/xen/arch/x86/mm/p2m-ept.c
> +++ b/xen/arch/x86/mm/p2m-ept.c
> @@ -1127,6 +1127,7 @@ void ept_sync_domain(struct p2m_domain *
>
>  static void ept_enable_pml(struct p2m_domain *p2m)
>  {
> +    p2m->ept.ept_ad = 1;
>      /*
>       * No need to check if vmx_domain_enable_pml has succeeded or not, as
>       * ept_p2m_type_to_flags will do the check, and write protection will be
> @@ -1137,6 +1138,7 @@ static void ept_enable_pml(struct p2m_do
>
>  static void ept_disable_pml(struct p2m_domain *p2m)
>  {
> +    p2m->ept.ept_ad = 0;
>      vmx_domain_disable_pml(p2m->domain);
>  }
>
> @@ -1164,8 +1166,6 @@ int ept_p2m_init(struct p2m_domain *p2m)
>
>      if ( cpu_has_vmx_pml )
>      {
> -        /* Enable EPT A/D bits if we are going to use PML. */
> -        ept->ept_ad = cpu_has_vmx_pml ? 1 : 0;
>          p2m->enable_hardware_log_dirty = ept_enable_pml;
>          p2m->disable_hardware_log_dirty = ept_disable_pml;
>          p2m->flush_hardware_cached_dirty = ept_flush_pml_buffers;
>
>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel
>



-- 
Thanks,
-Kai

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel