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 B281DC433F5 for ; Sat, 26 Feb 2022 00:17:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241057AbiBZARb (ORCPT ); Fri, 25 Feb 2022 19:17:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50664 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240359AbiBZARA (ORCPT ); Fri, 25 Feb 2022 19:17:00 -0500 Received: from mail-pg1-x54a.google.com (mail-pg1-x54a.google.com [IPv6:2607:f8b0:4864:20::54a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9B3CE2261D1 for ; Fri, 25 Feb 2022 16:16:20 -0800 (PST) Received: by mail-pg1-x54a.google.com with SMTP id t18-20020a63dd12000000b00342725203b5so3458097pgg.16 for ; Fri, 25 Feb 2022 16:16:20 -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=mkmQ6MFrlZy4eKd/Q3wbeOobNp7CN8W6giifpouEK3Q=; b=HNIMRDG1beTnwyz26v1dtXmdSZhkkNIT50ZAUvd6nR9l9tMgyyLfGhzlV+OqJCPEHw TiL7s2zfof/Z0d7TYvcEljJ0Z5/Rlzqge6Cu2y6WB6ZEdqWGgH9Del7NJBRv9vdYGZlG ROSoidAZmK6YDct2cNe23Qz5WbKtSXyHAPHDu4a1VCAgcib73hMUvWeBlkIljaSMzrGe kePNhRjQ0u4Z+bNIpQUXw5KynJ8w7BCfpUeXOeq6brTm1zXLiRPEgsDhf4QiDt7kx+So cJyGEZ46LlQfjFZ+eUlOlAveINLeZxzBEKSBRJlkE06aDrtbOo5uGcxLK97/LpUa6ped 0dlA== 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=mkmQ6MFrlZy4eKd/Q3wbeOobNp7CN8W6giifpouEK3Q=; b=3e8G9m+eSHE6lp0A1hg+YHZWJgJtUfxxwbcjRpJpQrzcX5+jgByiUB1D2bfdmBaunu 9HL+v4HAUB/t3yreuxFml1MUJMqnrjibOL8YV5i07A6MxOTDsdJ1ZVIbXY4zEzB+Ex0L XucTjf3bNCUVlfL7pRdESwCsdihfSKkS0GlSL6on8NojttDQvyC1OwAaGM/DGm9ymJi4 5AC3BaX+iGNBH7ZOrXyL1DZfUOqSEC1wLj82d9WRS1Q6HFfb1BE4HgxYWSS6opWW4O4O SM69HFjwEa/LkDT6efqHP9Ar9Dawhz5MMDDWZj2VQk/b8xvnVf5OlMm6wrtQArzdNAhY aoBQ== X-Gm-Message-State: AOAM531ieuEqrdt+NV4zKYVlGM2v2VvSsbwCemI+0JnhKJODov7RUt57 b9XwQdAjQWknJigkTHLlrJtQ9sN3MKk= X-Google-Smtp-Source: ABdhPJyWCyvm2sgSjm0RwiuidMtkOSbJaGbyT+NiwBP55uKTx1afDWW6MyIdn7+BA//anx1BPN3Dk9lol4Y= X-Received: from seanjc.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:3e5]) (user=seanjc job=sendgmr) by 2002:a05:6a00:124f:b0:4c0:6242:c14e with SMTP id u15-20020a056a00124f00b004c06242c14emr10089164pfi.83.1645834580082; Fri, 25 Feb 2022 16:16:20 -0800 (PST) Reply-To: Sean Christopherson Date: Sat, 26 Feb 2022 00:15:29 +0000 In-Reply-To: <20220226001546.360188-1-seanjc@google.com> Message-Id: <20220226001546.360188-12-seanjc@google.com> Mime-Version: 1.0 References: <20220226001546.360188-1-seanjc@google.com> X-Mailer: git-send-email 2.35.1.574.g5d30c73bfb-goog Subject: [PATCH v3 11/28] KVM: x86/mmu: WARN if old _or_ new SPTE is REMOVED in non-atomic path From: Sean Christopherson To: Paolo Bonzini , Christian Borntraeger , Janosch Frank , Claudio Imbrenda Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , David Hildenbrand , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, David Matlack , Ben Gardon , Mingwei Zhang Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 Reviewed-by: Ben Gardon --- 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 8fbf3364f116..1dcdf1a4fcc1 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -640,13 +640,13 @@ 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); -- 2.35.1.574.g5d30c73bfb-goog