From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: [PATCH] KVM: MMU: Document large pages Date: Tue, 1 Jun 2010 16:33:42 -0300 Message-ID: <20100601193342.GA30290@amt.cnet> References: <1274967852-31886-1-git-send-email-avi@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Xiao Guangrong , kvm@vger.kernel.org To: Avi Kivity Return-path: Received: from mx1.redhat.com ([209.132.183.28]:64558 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753044Ab0FAUJW (ORCPT ); Tue, 1 Jun 2010 16:09:22 -0400 Content-Disposition: inline In-Reply-To: <1274967852-31886-1-git-send-email-avi@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Thu, May 27, 2010 at 04:44:12PM +0300, Avi Kivity wrote: > Signed-off-by: Avi Kivity > --- > 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.