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 D174BC4332F for ; Sat, 20 Nov 2021 04:52:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237645AbhKTEzy (ORCPT ); Fri, 19 Nov 2021 23:55:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55188 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236738AbhKTEyn (ORCPT ); Fri, 19 Nov 2021 23:54:43 -0500 Received: from mail-pl1-x64a.google.com (mail-pl1-x64a.google.com [IPv6:2607:f8b0:4864:20::64a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AD8BEC0617A2 for ; Fri, 19 Nov 2021 20:51:13 -0800 (PST) Received: by mail-pl1-x64a.google.com with SMTP id p16-20020a170902e75000b0014271728fd6so5700026plf.18 for ; Fri, 19 Nov 2021 20:51:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=reply-to:date:in-reply-to:message-id:mime-version:references :subject:from:to:cc; bh=9UpU4BE6VFo1yV37uGFOyLOiPpm09nWvBtlMWiwFN2c=; b=Uu4CsIhMP3+cMa1fhkvrE8BfxHMibIcsUwThV/W74PSvsBKNkgzf3eDebBCnJhnavS ARX1Md/3uCA5OsEEZYJXFSHVPvSqgeMkkFJDN2lnWsp2ftADf3+ZVMXuEozWh00mzMK0 lYaIw8Xc6C8Px2tICCiphBwTYNLTV73WjQk+1aQAe0h4N/EVdlndBrBd8j2brHWpIFRe qxyrD+fuTMybPbVOp33wQExUmFNQcdzjbc7c3eKqWzn2CpcYAgZDfcbGZrgyJft4fFrt qS6IDfmiT0Z+ZLf168qo4vtcdI9zlC9TvmO9aUQrvQqzu6YnTMkWDc75Wd80nlfow3+o q2Qg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:reply-to:date:in-reply-to:message-id :mime-version:references:subject:from:to:cc; bh=9UpU4BE6VFo1yV37uGFOyLOiPpm09nWvBtlMWiwFN2c=; b=xEIUh96B26iJ/A0l2+nc7VgZ9Oc1iTjEbMuWIX/AgFp6c1EQQgLkwqm/ajflVjDDuN SiDk/EDXQZozOXYCM0J94iMODzggt0oAXUdwEyRwvYLN9ayzU+cnZ3t9WNh871KFwP0g n8Y+ZK1TjroTmsLVUi9KqaSL5Ta7Se2yB/zlY0socoPAWgm58h3dkCF9XOWu9QOCUdWh jOmGELIputMyAyQotV0J2w7kYZOCfb+/sSKyiZ+rL/UacEdIeqWi4yDMmPLyL2G9KazO 5lyNSpWpYvzO8GYJC2kQCqCtWiBClQi5HqQrNyiq+Zx8/0N7K6bYgpskd+BlchykTA7z SGdQ== X-Gm-Message-State: AOAM532ncl5yN1qCEUMaiMg7QsCeQcrFVX/vYWL3QlbaEFaoMEjnH5Gy GQFJZNyYTslY7a4OpBkOW9/VMxHOjqg= X-Google-Smtp-Source: ABdhPJznjPegzC1rG8W9ZRF82xewliW8LitZrqmb/apQMZE5Itj2eER1+glAZ5x+5+M7a2aPuhx3Qq0KrWQ= X-Received: from seanjc.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:3e5]) (user=seanjc job=sendgmr) by 2002:a05:6a00:1816:b0:49f:cd0d:b51b with SMTP id y22-20020a056a00181600b0049fcd0db51bmr68908861pfa.6.1637383873184; Fri, 19 Nov 2021 20:51:13 -0800 (PST) Reply-To: Sean Christopherson Date: Sat, 20 Nov 2021 04:50:30 +0000 In-Reply-To: <20211120045046.3940942-1-seanjc@google.com> Message-Id: <20211120045046.3940942-13-seanjc@google.com> Mime-Version: 1.0 References: <20211120045046.3940942-1-seanjc@google.com> X-Mailer: git-send-email 2.34.0.rc2.393.gf8c9666880-goog Subject: [PATCH 12/28] KVM: x86/mmu: Batch TLB flushes from TDP MMU for MMU notifier change_spte From: Sean Christopherson To: Paolo Bonzini Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Hou Wenlong , Ben Gardon Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Batch TLB flushes (with other MMUs) when handling ->change_spte() notifications in the TDP MMU. The MMU notifier path in question doesn't allow yielding and correcty flushes before dropping mmu_lock. Signed-off-by: Sean Christopherson --- arch/x86/kvm/mmu/tdp_mmu.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 8e446ef03022..06b500fab248 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -1182,13 +1182,12 @@ static bool set_spte_gfn(struct kvm *kvm, struct tdp_iter *iter, */ bool kvm_tdp_mmu_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) { - bool flush = kvm_tdp_mmu_handle_gfn(kvm, range, set_spte_gfn); - - /* FIXME: return 'flush' instead of flushing here. */ - if (flush) - kvm_flush_remote_tlbs_with_address(kvm, range->start, 1); - - return false; + /* + * No need to handle the remote TLB flush under RCU protection, the + * target SPTE _must_ be a leaf SPTE, i.e. cannot result in freeing a + * shadow page. See the WARN on pfn_changed in __handle_changed_spte(). + */ + return kvm_tdp_mmu_handle_gfn(kvm, range, set_spte_gfn); } /* -- 2.34.0.rc2.393.gf8c9666880-goog