From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 903D5C432C0 for ; Wed, 27 Nov 2019 18:15:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6ED4A2070B for ; Wed, 27 Nov 2019 18:15:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727040AbfK0SPl (ORCPT ); Wed, 27 Nov 2019 13:15:41 -0500 Received: from mga18.intel.com ([134.134.136.126]:13404 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726576AbfK0SPl (ORCPT ); Wed, 27 Nov 2019 13:15:41 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Nov 2019 10:15:40 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,250,1571727600"; d="scan'208";a="383579517" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.41]) by orsmga005.jf.intel.com with ESMTP; 27 Nov 2019 10:15:40 -0800 Date: Wed, 27 Nov 2019 10:15:40 -0800 From: Sean Christopherson To: Ben Gardon Cc: kvm@vger.kernel.org, Paolo Bonzini , Peter Feiner , Peter Shier , Junaid Shahid , Jim Mattson Subject: Re: [RFC PATCH 01/28] kvm: mmu: Separate generating and setting mmio ptes Message-ID: <20191127181540.GA22227@linux.intel.com> References: <20190926231824.149014-1-bgardon@google.com> <20190926231824.149014-2-bgardon@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190926231824.149014-2-bgardon@google.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, Sep 26, 2019 at 04:17:57PM -0700, Ben Gardon wrote: > Separate the functions for generating MMIO page table entries from the > function that inserts them into the paging structure. This refactoring > will allow changes to the MMU sychronization model to use atomic > compare / exchanges (which are not guaranteed to succeed) instead of a > monolithic MMU lock. > > Signed-off-by: Ben Gardon > --- > arch/x86/kvm/mmu.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index 5269aa057dfa6..781c2ca7455e3 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -390,8 +390,7 @@ static u64 get_mmio_spte_generation(u64 spte) > return gen; > } > > -static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn, > - unsigned access) > +static u64 generate_mmio_pte(struct kvm_vcpu *vcpu, u64 gfn, unsigned access) Maybe get_mmio_spte_value()? I see "generate" and all I can think of is the generation number and nothing else. > { > u64 gen = kvm_vcpu_memslots(vcpu)->generation & MMIO_SPTE_GEN_MASK; > u64 mask = generation_mmio_spte_mask(gen); > @@ -403,6 +402,17 @@ static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn, > mask |= (gpa & shadow_nonpresent_or_rsvd_mask) > << shadow_nonpresent_or_rsvd_mask_len; > > + return mask; > +} > + > +static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn, > + unsigned access) > +{ > + u64 mask = generate_mmio_pte(vcpu, gfn, access); > + unsigned int gen = get_mmio_spte_generation(mask); > + > + access = mask & ACC_ALL; > + > trace_mark_mmio_spte(sptep, gfn, access, gen); > mmu_spte_set(sptep, mask); > } > -- > 2.23.0.444.g18eeb5a265-goog >