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 C14E4C43219 for ; Mon, 7 Feb 2022 16:15:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345820AbiBGQOp (ORCPT ); Mon, 7 Feb 2022 11:14:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50230 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232706AbiBGQKE (ORCPT ); Mon, 7 Feb 2022 11:10:04 -0500 Received: from mail-pl1-x634.google.com (mail-pl1-x634.google.com [IPv6:2607:f8b0:4864:20::634]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DF7E1C0401CF for ; Mon, 7 Feb 2022 08:10:02 -0800 (PST) Received: by mail-pl1-x634.google.com with SMTP id u12so4368942plq.10 for ; Mon, 07 Feb 2022 08:10:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=xiSBzPQnTG+yIHuJ7k7x6ADsNTF+1w12491gzVcMAFE=; b=ZbB3crbAr+DzqHrDW5Wa8yEKGFB41seBarYw/+E5gPl3dirtURFGGzZ5zhYw3d1vg5 FdW1Gih98v5ar8dHJBsPRS7twDQgTBUtxRh3/aLC4PuerU5TfB9hvDDGxs+xE72BGbe8 vxo84b+Mkfy5EU/P6GHDHkw5M3Ukn9Kn1G8ZOlG4BGoNjSCXabmc0C3yMadA5vBZmddf vU8HLzOLMQeRJTdxuj/Uzzqx62U4WyDC4oMoJM6mJEQ/NP2wOOiN/Q59NINXhQ0cdnJM R4H9/dJBXlmZTjjEn/6KotsLQzQGNfMutC0lPaHyHoSpVj6AmKHbmSJVa2+pwlNVhEuQ l6pw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=xiSBzPQnTG+yIHuJ7k7x6ADsNTF+1w12491gzVcMAFE=; b=QHOg6gjOvBNbtSSMadPdjQYeabf+zDbcDN9EXQBJEFg/KixxxSOyaPoFPvv7KyAR0S mDCI1wAtKAso0VA+j8iCZ8p5s2oON0eUdWpP2vVR3BCwqsRxrnu13CoHrVsNKYVqeD2j /GxQr+upl+2gCpJQW3EP500qO7FbVar+tP5FzcQt/lG+LCCEVWpTli90TjRn20WuilL8 tmv36jAhdz8XGhEQq0EH/kTwLCzRIlKC0bnhBsiXLrNxnDgxmqQU6UQIBVwJVrUjyCuJ pJ95HIWF+sv4LUSLXbD4Xy/xLzPM5r5jxLFeRo33F9SbEmL6IJmvev3zLkIBRpY5aRju FmRw== X-Gm-Message-State: AOAM53345WE1UMbP2+VhjcfwLEVIn2hPYECJTq+QKyqEMbEh1kERiubq haskA3HrpsvJphg1Nf8/lOt6FQ== X-Google-Smtp-Source: ABdhPJwRrTS8wrHCH7GEaOUas2bOM2kxOBaDos9y+CXKADhOyp3DgXUB0Ig+/gcWE2Wba/Q7POrZhw== X-Received: by 2002:a17:90b:2251:: with SMTP id hk17mr19523346pjb.210.1644250202261; Mon, 07 Feb 2022 08:10:02 -0800 (PST) Received: from google.com (157.214.185.35.bc.googleusercontent.com. [35.185.214.157]) by smtp.gmail.com with ESMTPSA id s32sm6788998pfw.80.2022.02.07.08.10.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Feb 2022 08:10:01 -0800 (PST) Date: Mon, 7 Feb 2022 16:09:58 +0000 From: Sean Christopherson To: Paolo Bonzini Cc: David Matlack , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, vkuznets@redhat.com Subject: Re: [PATCH 01/23] KVM: MMU: pass uses_nx directly to reset_shadow_zero_bits_mask Message-ID: References: <20220204115718.14934-1-pbonzini@redhat.com> <20220204115718.14934-2-pbonzini@redhat.com> <8081cbe5-6d12-9f99-9f0f-13c1d7617647@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8081cbe5-6d12-9f99-9f0f-13c1d7617647@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Feb 05, 2022, Paolo Bonzini wrote: > On 2/4/22 18:59, David Matlack wrote: > > > + reset_shadow_zero_bits_mask(vcpu, context, is_efer_nx(context)); > > > > Out of curiousity, how does KVM mitigate iTLB multi-hit when shadowing > > NPT and the guest has not enabled EFER.NX? > > You got me worried for a second but iTLB multihit is Intel-only, isn't it? AFAIK, yes, big Core only. arch/x86/kernel/cpu/common.c sets NO_ITLB_MULTIHIT for all AMD, Hygon, and Atom CPUs.