Re: [PATCH] KVM: MMU: Document large pages

[Marcelo Tosatti <mtosatti@redhat.com>]

On Thu, May 27, 2010 at 04:44:12PM +0300, Avi Kivity wrote:
> Signed-off-by: Avi Kivity <avi@redhat.com>
> ---
>  Documentation/kvm/mmu.txt |   23 +++++++++++++++++++++++
>  1 files changed, 23 insertions(+), 0 deletions(-)
> 
> diff --git a/Documentation/kvm/mmu.txt b/Documentation/kvm/mmu.txt
> index 1e7ecdd..6a0cab2 100644
> --- a/Documentation/kvm/mmu.txt
> +++ b/Documentation/kvm/mmu.txt
> @@ -317,6 +317,29 @@ on fault type:
>  
>  (user write faults generate a #PF)
>  
> +Large pages
> +===========
> +
> +The mmu supports all combinations of large and small guest and host pages.
> +Supported page sizes include 4k, 2M, 4M, and 1G.  4M pages are treated as
> +two separate 2M pages, on both guest and host, since the mmu always uses PAE
> +paging.
> +
> +To instantiate a large spte, four constraints must be satisfied:
> +
> +- the spte must point to a large host page
> +- the guest pte must be a large pte of at least equivalent size (if tdp is
> +  enabled, there is no guest pte and this condition is satisified)
> +- if the spte will be writeable, the large page frame may not overlap any
> +  write-protected pages
> +- the guest guest pte must be wholly contained by a single memory slot

Fixed this "guest guest pte" typo and applied.