From nobody Mon Feb 9 00:54:17 2026 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 83A1CC41513 for ; Sat, 29 Jul 2023 00:49:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236917AbjG2Atk (ORCPT ); Fri, 28 Jul 2023 20:49:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41704 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236991AbjG2AtX (ORCPT ); Fri, 28 Jul 2023 20:49:23 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 35D75421D for ; Fri, 28 Jul 2023 17:48:45 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id 3f1490d57ef6-d1851c52f3dso2422799276.1 for ; Fri, 28 Jul 2023 17:48:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1690591661; x=1691196461; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=RfXXcqZt8v+vEMviQaB4ha8ro96aOmyFYUDExhL33FE=; b=D+29wkyjLypapSHoJge1mpaMfPBHgyoydIEBosT6gdt3ZIvLSr9lW379+2twDS+9NN x8d9jNCpmbUF5qFqVmqFdk+q9BOi6GRROVAhUNufVZHuH6xCedDb3S1GXzaf2+a6ZkYX WcXffBZ+IgjsHuqASHKxYMFPAvTTogbstpNmvwdmcZfL5QGGqsYFEVkYc1tStEL2L7sv dyx2fHZlILnrsMXJcxTxFXr21doH+/dcswCPHamiZcg0CTfh3gRu70ahmuRwaMmXANTi 8kjx7ldkDSK4tsFuKQyxCI2MgK/iVhypCHeoILCPx/DAHwGdTB54OBNagVdOVid8O9KI lAUg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690591661; x=1691196461; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=RfXXcqZt8v+vEMviQaB4ha8ro96aOmyFYUDExhL33FE=; b=T46VBhX77jS4T8hsNiWk9kDgrO4axsDjtGLSmTaHvksmnEsp+tYIqhKkytG7vTzabx sG8pq/cKEnhRbrxDQjZzYBBhLzAQ9RqklMNFUPIqD38hVVomoXMLtLC0cL0HG1Nu5Cdn CYPJIFr6Pd+Ar7hWKv2gqDF9X5K125zz6/kEQeNXHntTlkDmfKS7/TOP7h7M0ChXMnoS EKwGKkjEFi3IIixHNtiyoUoSXBmp+WNsiEN3mwCSqWstKL6KGt2DFHMk9paJq7yWCrkV ZMwFcUxkGLJQrMfvn/XkbM3eR3aHB7uipZkdGdGhjC1RystKKVi5ltAo4fcKM0T7UVj2 59Rw== X-Gm-Message-State: ABy/qLYZqKvWTDndV5p91Y7HsCj6HHY/sq3QoF/HJMwGR+t45sDrdCTm Lzi++58WxucNrIIMSkJ4uVhQXEcywJs= X-Google-Smtp-Source: APBJJlERmrEreSp3KWVd66uKyABQJknJ32dmGyLRrH0CXCcgkp0WqemQ/bWIBdjSnDq4poF74oFl4nwqsdI= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a05:6902:100f:b0:cf9:3564:33cc with SMTP id w15-20020a056902100f00b00cf9356433ccmr24322ybt.13.1690591660993; Fri, 28 Jul 2023 17:47:40 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 28 Jul 2023 17:47:19 -0700 In-Reply-To: <20230729004722.1056172-1-seanjc@google.com> Mime-Version: 1.0 References: <20230729004722.1056172-1-seanjc@google.com> X-Mailer: git-send-email 2.41.0.487.g6d72f3e995-goog Message-ID: <20230729004722.1056172-10-seanjc@google.com> Subject: [PATCH v3 09/12] KVM: x86/mmu: Replace MMU_DEBUG with proper KVM_PROVE_MMU Kconfig From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Mingwei Zhang , David Matlack , Jim Mattson Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Replace MMU_DEBUG, which requires manually modifying KVM to enable the macro, with a proper Kconfig, KVM_PROVE_MMU. Now that pgprintk() and rmap_printk() are gone, i.e. the macro guards only KVM_MMU_WARN_ON() and won't flood the kernel logs, enabling the option for debug kernels is both desirable and feasible. Signed-off-by: Sean Christopherson Reviewed-by: Philippe Mathieu-Daud=C3=A9 --- arch/x86/kvm/Kconfig | 13 +++++++++++++ arch/x86/kvm/mmu/mmu.c | 2 +- arch/x86/kvm/mmu/mmu_internal.h | 4 +--- 3 files changed, 15 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig index 89ca7f4c1464..4e5a282cc518 100644 --- a/arch/x86/kvm/Kconfig +++ b/arch/x86/kvm/Kconfig @@ -138,6 +138,19 @@ config KVM_XEN =20 If in doubt, say "N". =20 +config KVM_PROVE_MMU + bool "Prove KVM MMU correctness" + depends on DEBUG_KERNEL + depends on KVM + depends on EXPERT + help + Enables runtime assertions in KVM's MMU that are too costly to enable + in anything remotely resembling a production environment, e.g. this + gates code that verifies a to-be-freed page table doesn't have any + present SPTEs. + + If in doubt, say "N". + config KVM_EXTERNAL_WRITE_TRACKING bool =20 diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index d46f77734f30..21ced900c3e9 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -1695,7 +1695,7 @@ bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn= _range *range) =20 static void kvm_mmu_check_sptes_at_free(struct kvm_mmu_page *sp) { -#ifdef MMU_DEBUG +#ifdef CONFIG_KVM_PROVE_MMU int i; =20 for (i =3D 0; i < SPTE_ENT_PER_PAGE; i++) { diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_interna= l.h index cfe925fefa68..40e74db6a7d5 100644 --- a/arch/x86/kvm/mmu/mmu_internal.h +++ b/arch/x86/kvm/mmu/mmu_internal.h @@ -6,9 +6,7 @@ #include #include =20 -#undef MMU_DEBUG - -#ifdef MMU_DEBUG +#ifdef CONFIG_KVM_PROVE_MMU #define KVM_MMU_WARN_ON(x) WARN_ON_ONCE(x) #else #define KVM_MMU_WARN_ON(x) do { } while (0) --=20 2.41.0.487.g6d72f3e995-goog