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 43544C43219 for ; Thu, 10 Nov 2022 01:48:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232197AbiKJBs3 (ORCPT ); Wed, 9 Nov 2022 20:48:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45840 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230323AbiKJBsZ (ORCPT ); Wed, 9 Nov 2022 20:48:25 -0500 Received: from mail-pj1-x104a.google.com (mail-pj1-x104a.google.com [IPv6:2607:f8b0:4864:20::104a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AA1FCB78 for ; Wed, 9 Nov 2022 17:48:24 -0800 (PST) Received: by mail-pj1-x104a.google.com with SMTP id pj8-20020a17090b4f4800b002140219b2b3so3281883pjb.0 for ; Wed, 09 Nov 2022 17:48:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:reply-to:from:to:cc :subject:date:message-id:reply-to; bh=czRAUIKopWS6UNhZrlaJNdPvNfcaMl7pKNzRt/2ikJM=; b=fpoDzxDMW+3u08v36DNw63uremA9sbsMmIFu2x8khM3/gBySJsYse9ASpc0svRbvn3 WQfcM4iyPITgrDTDgu2S+qClNj83o6nuifGmu20kTjfEirlD/zB2d5DAxK+98c5vAtNY 4EqK+gmP3PZu4PVATaG3O6S9sjZ3mhBPlKsQZnOiDOKOKlP0GVBzxW/QYbH1w9P71/Ch 3NKukEyx9UR9a0oNc8eyQWd/KcZHZBuzxeiSeCmK6itvS7/7XGxSuME1jWAUJKhbEdRq hRBlvRJb58rTmNTItfyIlGspaQC3OCJAVlM3te1nuqOjNjiR2hNHdUbClxbUl80OrtAZ +3kw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:reply-to :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=czRAUIKopWS6UNhZrlaJNdPvNfcaMl7pKNzRt/2ikJM=; b=2eEL8KSU/3iiA8swVucFi9Sx1HrdH79Neg3QWwlrTj1eacPpCZe9FLdoWaLLAgHdv0 p2pQiK4S4dyO4RTyo7uhVtyvqLnula+Rp2eMZpEuSYCM1RAZ2vmPT+J3SPjZMyhMmj55 n+5YMspr5vzrdF3rb1qiWya+wrT1T4mfDZ1dfMgHJUiUhvAPZzC/KaQNx4NvaAGuzQvU XO01bxHhgl7zB/JEsksOIhTLjTDkPw++YXIvcrLdxzS6cTmQnsyayRvAVL39tSq5XGw0 1FvxeD4C7wzHsOY4g9Nh4jGOqLnPUQhesLaJsZRgMQWpYrK6t0UMEy4gJJCo949WLc0j 8/YA== X-Gm-Message-State: ACrzQf2MLXHNGEdHIlOtKErJLM/999mRsp7UmaB3AfUqiYc3qW2rj272 qDxeaOXNa27CPEoZItQuzitmSzwpF2U= X-Google-Smtp-Source: AMsMyM6/3/k/CW504Zws+OFFGRxwl1sYlYMYPI5zGDC9GxPtGjRoTYY/y/tk9KC1z2QJzEV+7Zl3zdqVVNs= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a62:1b11:0:b0:56d:568d:c293 with SMTP id b17-20020a621b11000000b0056d568dc293mr55789021pfb.41.1668044904195; Wed, 09 Nov 2022 17:48:24 -0800 (PST) Reply-To: Sean Christopherson Date: Thu, 10 Nov 2022 01:48:19 +0000 Mime-Version: 1.0 X-Mailer: git-send-email 2.38.1.431.g37b22c650d-goog Message-ID: <20221110014821.1548347-1-seanjc@google.com> Subject: [PATCH 0/2] KVM: x86/mmu: Use page-track only for... page tracking From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Yan Zhao Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Don't bounce through the page-track notifier when zapping+flushing SPTEs in response to memslot changes as the need to zap+flush isn't strictly limited to page-tracking. With that done, register KVM's notifier on the first allocation of a shadow root, as KVM's ->track_write() hook is used only to react to writes to gPTEs. Aside from avoiding a RETPOLINE on emulated writes, dropping KVM's internal use will allow removing ->track_flush_slot() altogether once KVM-GT moves to a different hook[*]. Tracking "flushes" of slots is a poor fit for KVM-GT's needs as KVM-GT needs to drop its write-protection only when a memslot change is guaranteed to be committed, whereas the "flush" call is speculative in the sense that KVM may abort a memslot update after flushing the original memslot. https://lore.kernel.org/all/20221108084416.11447-1-yan.y.zhao@intel.com Sean Christopherson (2): KVM: x86/mmu: Don't rely on page-track mechanism to flush on memslot change KVM: x86/mmu: Register page-tracker on first shadow root allocation arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/mmu/mmu.c | 24 ++++++++---------------- arch/x86/kvm/x86.c | 2 ++ 3 files changed, 11 insertions(+), 16 deletions(-) base-commit: d663b8a285986072428a6a145e5994bc275df994 -- 2.38.1.431.g37b22c650d-goog