Re: [PATCH 3/3] KVM: VMX: Enable EPT 1GB page support

[Sheng Yang <sheng@linux.intel.com>]

On Tuesday 05 January 2010 18:43:21 Avi Kivity wrote:
> On 01/05/2010 12:12 PM, Sheng Yang wrote:
> > Signed-off-by: Sheng Yang<sheng@linux.intel.com>
> > ---
> >   arch/x86/include/asm/vmx.h |    1 +
> >   arch/x86/kvm/mmu.c         |    8 +++++---
> >   arch/x86/kvm/vmx.c         |   11 ++++++++++-
> >   3 files changed, 16 insertions(+), 4 deletions(-)
> >
> > diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
> > index 713ed9a..43f1e9b 100644
> > --- a/arch/x86/include/asm/vmx.h
> > +++ b/arch/x86/include/asm/vmx.h
> > @@ -364,6 +364,7 @@ enum vmcs_field {
> >   #define VMX_EPTP_UC_BIT				(1ull<<  8)
> >   #define VMX_EPTP_WB_BIT				(1ull<<  14)
> >   #define VMX_EPT_2MB_PAGE_BIT			(1ull<<  16)
> > +#define VMX_EPT_1GB_PAGE_BIT			(1ull<<  17)
> 
> Can you share when this feature will be available in hardware?

I think it should be with the 32nm Core i7 (at least highend server edition), 
slated for early 2010 release.
> 
> >   static int vmx_get_lpage_level(void)
> >   {
> > -	return 2; /* PT_DIRECTORY_LEVEL */
> > +	if (enable_ept&&  !cpu_has_vmx_ept_1g_page())
> > +		return 2; /* PT_DIRECTORY_LEVEL */
> > +	else
> > +		/* For shadow and EPT supported 1GB page */
> > +		return 3; /* PT_PDPE_LEVEL */
> >   }
> 
> Why not use the defines instead of numbers?  It will reduce change when
> we change PT_*_LEVEL to be zero based instead of one based.

Oh, sure (caused by a little chaos in mind...). Patch 1 is also 
affected(cpuid). Would resent the patchset soon.

> 
> Patchset looks good; second patch should go into .33 and stable, no?
> 
Sure. I would cc stable later.

-- 
regards
Yang, Sheng