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 F22DEC433FE for ; Sat, 20 Nov 2021 04:52:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237241AbhKTEzu (ORCPT ); Fri, 19 Nov 2021 23:55:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54988 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236900AbhKTEyq (ORCPT ); Fri, 19 Nov 2021 23:54:46 -0500 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E58EC0613B3 for ; Fri, 19 Nov 2021 20:51:20 -0800 (PST) Received: by mail-yb1-xb4a.google.com with SMTP id h134-20020a25d08c000000b005f5cd3befbbso842023ybg.10 for ; Fri, 19 Nov 2021 20:51:20 -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=5jSoienwu2EmQOFwC5eYL0nZeslWeLTguu5n+4aZuFQ=; b=s4dD3+6VYlLhcv66XkqJRvRBAUDhX5CksHNJcZ+vbxMaHEYu0sTmyfb0wcvMc8LYkL ko8CDsSC0npN1JD/73980BUYUF3JvGw6DCngO4Nfso9fRKj9MHU+CRILd+JnRuqpkCDp bFniUTcdHwF10jSOUa/0Ri1Smv6nRBHh8vWg+T4SrPgc99JCXci+1v8j55BkU8p9JGkI 8Wj+ks5XFgKjbiy9jfb229VoP8PYE+xydJSnIMJWxrFt2TZN20ERLnOFenCo7Th/rFHa kk0/w+rN9XXblron+ISNzLbyeEyiPLz9LLjEfogoaLim7wR5e8/QpZ9STPzstAdapj2b h+uw== 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=5jSoienwu2EmQOFwC5eYL0nZeslWeLTguu5n+4aZuFQ=; b=PuvEpzUQ3bT1Iz+O5ueu8fflqnALt+oY5asy+q9JgtfFM2Z1qrezI/NAMEalujVQKt 6ldQ/tvAdXZZwPOtFoTUYCh/mj2Sdonja1CcIN0HemoxavgMt5olW/IdTYF55Iv8bV0C VKR1m9WG7ICb8fcgFs5/YxgQg9HKBBgwDq5f+AgVlNCzqmRH/t8H6rFt+VRbyvu0OQoA usdTawaqseYz90gjYPk5xY+aeTc2dkpxyFvzyd8ZYUUQLzsfjQPHTjpGO190wGlaWSBu Af0DiwC2NIvAYwZfesUXbtrBE2MKplWnAsCgOKgTDOgMT0MNFNR2abk7X2o22OmYn9Kw hPVg== X-Gm-Message-State: AOAM532u59BkfVsmmWdoPB6SzV0CQHRDmUEquhbGigFT4pdG33jchd0Y zifwns4tq9AnzXEaWDv+MVaBMdHtv+0= X-Google-Smtp-Source: ABdhPJxbdy+I6Hql4u/1zRTRDXVZETSx8iioHLVbrSAgX4s52XvY3QTZxioyq1Jzc9vDvc8T1m94bvU2NO4= X-Received: from seanjc.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:3e5]) (user=seanjc job=sendgmr) by 2002:a25:a427:: with SMTP id f36mr41341862ybi.245.1637383879396; Fri, 19 Nov 2021 20:51:19 -0800 (PST) Reply-To: Sean Christopherson Date: Sat, 20 Nov 2021 04:50:34 +0000 In-Reply-To: <20211120045046.3940942-1-seanjc@google.com> Message-Id: <20211120045046.3940942-17-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 16/28] KVM: x86/mmu: WARN if old _or_ new SPTE is REMOVED in non-atomic path 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 WARN if the new_spte being set by __tdp_mmu_set_spte() is a REMOVED_SPTE, which is called out by the comment as being disallowed but not actually checked. Keep the WARN on the old_spte as well, because overwriting a REMOVED_SPTE in the non-atomic path is also disallowed (as evidence by lack of splats with the existing WARN). Fixes: 08f07c800e9d ("KVM: x86/mmu: Flush TLBs after zap in TDP MMU PF handler") Cc: Ben Gardon Signed-off-by: Sean Christopherson --- arch/x86/kvm/mmu/tdp_mmu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 085f6b09e5f3..d9524b387221 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -638,13 +638,13 @@ static inline void __tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *iter, lockdep_assert_held_write(&kvm->mmu_lock); /* - * No thread should be using this function to set SPTEs to the + * No thread should be using this function to set SPTEs to or from the * temporary removed SPTE value. * If operating under the MMU lock in read mode, tdp_mmu_set_spte_atomic * should be used. If operating under the MMU lock in write mode, the * use of the removed SPTE should not be necessary. */ - WARN_ON(is_removed_spte(iter->old_spte)); + WARN_ON(is_removed_spte(iter->old_spte) || is_removed_spte(new_spte)); kvm_tdp_mmu_write_spte(iter->sptep, new_spte); -- 2.34.0.rc2.393.gf8c9666880-goog