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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4ED56C6FA82 for ; Tue, 13 Sep 2022 13:58:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232236AbiIMN60 (ORCPT ); Tue, 13 Sep 2022 09:58:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37672 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231827AbiIMN6Y (ORCPT ); Tue, 13 Sep 2022 09:58:24 -0400 Received: from mail-lj1-x231.google.com (mail-lj1-x231.google.com [IPv6:2a00:1450:4864:20::231]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CAFFB4F1B1 for ; Tue, 13 Sep 2022 06:58:23 -0700 (PDT) Received: by mail-lj1-x231.google.com with SMTP id r12so12925178ljg.10 for ; Tue, 13 Sep 2022 06:58:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date; bh=Xz00WUlNoMcvuGzmZoT3YtH17wlzSyS0xFHNgt419Gk=; b=lUsjBgilev82eRTIjXeALpddVB70OObeUL+rQ+CVv5Xz7/Q4E6xSSEMA+oNJJAKPOe BncPJ1pDrE40RjDYbevpdqqCaVYprSiklIRR89m40RyyKzVkl3z7N0t8REFBPPqGoGf3 IHb2qmPtSxCyptLqs0Y/1OZkm+P71HV8Bpd0JUYGUu7zThDlDWgL+wa488uVapxjXXhs JRzlTL8byDtmXAo5+YgYLRG8qxnYBxI4zfCHdjT5RiCro07MjRhcjw2JSZIJfbQcmIJB 2hd0sWlXmFAFEkUjEhBsFE4Os15LDehHDOpBkXbsZ1aHdUWwySLa8Wf6YH/gWZEN9XOV WScQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date; bh=Xz00WUlNoMcvuGzmZoT3YtH17wlzSyS0xFHNgt419Gk=; b=tDqeDRrHaBTnCaylWQiXAR+iIru1S9ArZFfoOfAFQR2lOBI2wbjoFOvtlKR7AxxiEi SdhVlziqWFbjflWdQxEje2NxZxwO5U5DBRaVvz4dHNWlArndpk+wdlZD60r3l5Z7O/h1 YNAEfPPKr+frzonxoGs4hRc/+wDcDVlsGxlqu0bMa1FhjrUh1U0dfD8JMzfMUGf3gZmz 0uXSvIP693x1bMH72HYw/IaoH1pzP2qauEBRLeLFlmDqfaOXk4kI0whF9e7D8yJsAwb9 CCeWUPMOA9Tyn8YAwan+TGVzLbgnX9uKp9vZgmC8e77uW7vhgafo7zTwUhjjVcA63sqY VkcA== X-Gm-Message-State: ACgBeo0KLquNbpO1nvRWVdlFRBOI24OSy86uPseX5BsvyXdZ2L5pMHvd Qmfve9BYNV7sqmZdU0PJAfBfRpJX00spGfplax7Bww== X-Google-Smtp-Source: AA6agR5QWnwHv7/mI5PgNzDnxLBkRSTaL9iTSsGQerlCdhGRn6rLQMQIjHYb/thVv6YxaFXuuAIQWCUykN5+EICUUB4= X-Received: by 2002:a2e:87d9:0:b0:26a:ceee:c77b with SMTP id v25-20020a2e87d9000000b0026aceeec77bmr9716521ljj.275.1663077502029; Tue, 13 Sep 2022 06:58:22 -0700 (PDT) MIME-Version: 1.0 References: <8baa40dad8496abb2adb1096e0cf50dcc5f66802.1661331396.git.houwenlong.hwl@antgroup.com> <20220913125833.GC113257@k08j02272.eu95sqa> In-Reply-To: <20220913125833.GC113257@k08j02272.eu95sqa> From: David Matlack Date: Tue, 13 Sep 2022 06:57:55 -0700 Message-ID: Subject: Re: [PATCH v2 6/6] KVM: x86/mmu: Use 1 as the size of gfn range for tlb flushing in FNAME(invlpg)() To: Hou Wenlong Cc: kvm list , Sean Christopherson , Paolo Bonzini , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , X86 ML , "H. Peter Anvin" , LKML Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, Sep 13, 2022 at 5:58 AM Hou Wenlong wrote: > > On Thu, Sep 08, 2022 at 01:40:16AM +0800, David Matlack wrote: > > On Wed, Aug 24, 2022 at 05:29:23PM +0800, Hou Wenlong wrote: > > > Only SP with PG_LEVLE_4K level could be unsync, so the size of gfn range > > > must be 1. > > > > > > Signed-off-by: Hou Wenlong > > > --- > > > arch/x86/kvm/mmu/paging_tmpl.h | 3 ++- > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h > > > index 04149c704d5b..486a3163b1e4 100644 > > > --- a/arch/x86/kvm/mmu/paging_tmpl.h > > > +++ b/arch/x86/kvm/mmu/paging_tmpl.h > > > @@ -937,7 +937,8 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva, hpa_t root_hpa) > > > > > > mmu_page_zap_pte(vcpu->kvm, sp, sptep, NULL); > > > if (is_shadow_present_pte(old_spte)) > > > - kvm_flush_remote_tlbs_sptep(vcpu->kvm, sptep); > > > + kvm_flush_remote_tlbs_gfn(vcpu->kvm, > > > + kvm_mmu_page_get_gfn(sp, sptep - sp->spt), 1); > > > > The third argument to kvm_flush_remote_tlbs_gfn() is the level, not the > > number of pages. But that aside, I don't understand why this patch is > > necessary. kvm_flush_remote_tlbs_sptep() should already do the right > > thing. > > > Since only SP with PG_LEVEL_4K level could be unsync, so the level must > be PG_LEVEL_4K, then sp->role.level access could be dropped. However, > I'm not sure whether it is useful. I can drop it if it is useless. Ah, I see. I would be surprised if avoiding the read of sp->role.level has any noticeable impact on VM performance so I vote to drop this patch. > > > > > > > if (!rmap_can_add(vcpu)) > > > break; > > > -- > > > 2.31.1 > > >