From nobody Tue Feb 10 23:01:46 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 66F05C7EE24 for ; Fri, 12 May 2023 00:00:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239741AbjELAAB (ORCPT ); Thu, 11 May 2023 20:00:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53644 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239696AbjEKX7m (ORCPT ); Thu, 11 May 2023 19:59:42 -0400 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 7CC158A7E for ; Thu, 11 May 2023 16:59:33 -0700 (PDT) Received: by mail-pj1-x104a.google.com with SMTP id 98e67ed59e1d1-24e4531d571so5135547a91.1 for ; Thu, 11 May 2023 16:59:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1683849571; x=1686441571; 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=cjA+0mSTLh3yCMsGFKEfBNcNTT0A0nkYa87zKPgDSZA=; b=HN5fg1TcfLW1GSMIq1qurpY6RT1MqPzo8sehXms4OzfTNvmXjZfLujx3S1VqvYHNTY fIIVjvido5iXylJ1btxzXdDI8yd5o1+kGrYyGOSJE2KesbbdtMQhkuKjm4ZovfIhsPWg ttqpocKZBKrG2aXudd7T6pSdIqNvlURaLQV3R7GJ3KW7f/I1u6Dsj7LY3YIqabmJbYol 3GCVV/ow1MWhY4j92o5CR+4Yu58vgJ7MWNjKyYV5Xp65FsZeurXCc8LiMx2MZoFCNBhx FGdOP0HpWUJGN91HXEGI9pCKp2yL+amhf7Y6f1vNXUCMAEUVVW2XUq0j9aiP8qZekuBe Giag== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683849571; x=1686441571; 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=cjA+0mSTLh3yCMsGFKEfBNcNTT0A0nkYa87zKPgDSZA=; b=e9xsZ2wAZ8OoiEXWBIp1kz5hWZ36kPDQNsSQkp68o508vbeTAfGydGFmH3XuO+y0aK wNlTGigMLhQorekXEcDFDtnAi6SZTCCdF8FaNAk6Xa48h1cATcl8uoCoEzE/8eyEX9Kw qIGVUMzrVZ4HRgMkgopoOWKb99MZdDRnWPxaq/nZQ3G1bHQP/ne83kNzwYqR92AvGkR1 OE/ITN9MBMCB1VVFRyC08aKoya1P1/JTVwPg6CSuGompTXo2gg5kObI+198xIv0mVWYh o3YNNdRZ/VD65PIaWCh6o9hr4f8q8dupk1avL3v0pigiOGfOJOfy08+AX2j5kItQ9QpH 6+kQ== X-Gm-Message-State: AC+VfDxxcytpA0Kmi2b9H8YGZNe/2d0MIk1hz1a6Qbv1aSHgVfcuzwrG wkv9GyOzok0wI2kpCpBKKH/BbPN8c4I= X-Google-Smtp-Source: ACHHUZ52hND3kQfsuqaR24n4SBVr5xhmzHxWfDp7/xsaI/5up5YSws+O7uE9UrE0UTjUIeaPSDpMjLAk8tE= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:90a:f989:b0:246:6a3a:6aec with SMTP id cq9-20020a17090af98900b002466a3a6aecmr6656579pjb.4.1683849571640; Thu, 11 May 2023 16:59:31 -0700 (PDT) Reply-To: Sean Christopherson Date: Thu, 11 May 2023 16:59:15 -0700 In-Reply-To: <20230511235917.639770-1-seanjc@google.com> Mime-Version: 1.0 References: <20230511235917.639770-1-seanjc@google.com> X-Mailer: git-send-email 2.40.1.606.ga4b1b128d6-goog Message-ID: <20230511235917.639770-8-seanjc@google.com> Subject: [PATCH 7/9] 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 --- arch/x86/kvm/Kconfig | 13 +++++++++++++ arch/x86/kvm/mmu/mmu.c | 4 ++-- arch/x86/kvm/mmu/mmu_internal.h | 4 +--- 3 files changed, 16 insertions(+), 5 deletions(-) diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig index 8e578311ca9d..cccedb424324 100644 --- a/arch/x86/kvm/Kconfig +++ b/arch/x86/kvm/Kconfig @@ -139,6 +139,19 @@ 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 4731d2bf5af6..d209d466d58f 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -1686,7 +1686,7 @@ bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn= _range *range) return young; } =20 -#ifdef MMU_DEBUG +#ifdef CONFIG_KVM_PROVE_MMU static int is_empty_shadow_page(u64 *spt) { u64 *pos; @@ -1700,7 +1700,7 @@ static int is_empty_shadow_page(u64 *spt) } return 1; } -#endif +#endif /* CONFIG_KVM_PROVE_MMU */ =20 /* * This value is the sum of all of the kvm instances's 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 2.40.1.606.ga4b1b128d6-goog