From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.alien8.de (mail.alien8.de [65.109.113.108]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0813776057; Wed, 7 Feb 2024 13:29:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=65.109.113.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707312593; cv=none; b=V9rLdjMh/Umm/2R5P+2ygE9GMQOulO/WNNGzxSO2XZfyB76//6kEm5wD/QBjusswCeS20Ng0s9aVief2gxDczsRcAQXnCLE/AKqywuHxQfapT07lYDTr9xjd9v109UdFLcfiGV1lcCXqcCVfYwKzULM3jaqGv9KefgAicQj+kWE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707312593; c=relaxed/simple; bh=GOVzmtWSf66S4P82oUwpsGJAlkj0KnTZycg0imHhp4c=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=MTAiST6W68nvuj1Mts8YxRNnYXixQ1yCgbL12kZUrQlCR+koZq7JCnpb6l46QFHuaP3CjGhVFCs2NR+5Wj461SlTsjZax0V9fefReGU7R5UmY+xH10e3tVxRzGpmMlTe6Z2TTpvLxoS++mHClLdfxEs6Y0UtG1AvICiH1/pOYlU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=alien8.de; spf=pass smtp.mailfrom=alien8.de; dkim=pass (4096-bit key) header.d=alien8.de header.i=@alien8.de header.b=cZxdnFNj; arc=none smtp.client-ip=65.109.113.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=alien8.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=alien8.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (4096-bit key) header.d=alien8.de header.i=@alien8.de header.b="cZxdnFNj" Received: from localhost (localhost.localdomain [127.0.0.1]) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTP id 9250040E016D; Wed, 7 Feb 2024 13:29:48 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at mail.alien8.de Authentication-Results: mail.alien8.de (amavisd-new); dkim=pass (4096-bit key) header.d=alien8.de Received: from mail.alien8.de ([127.0.0.1]) by localhost (mail.alien8.de [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id 1JezrvZZ9vpp; Wed, 7 Feb 2024 13:29:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=alien8; t=1707312586; bh=cq31hkoyQSWq8+AdjDLIdicd23/yb2pyABjFoySQ434=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=cZxdnFNj1RRZ8qo48nykAUGkBFTwZDESkMk3QDKq3It+3g304jQrXfl00+SFTSVmi FDQBOGjKsNb6luVHSPtL1GQjPRjZs7J7lxT23EOXKrmTHO/vOERNtcaqPdWjziL79f hukqyXdUH2PYhu5ObSzQutXPKMzr2SE8yTP7s3SrSrF8jXrhLUvvoI2+j0Ud1AmxRH cQN8ZXAUyuVyyVXyX+/8fLCZ+6Gc9zRjtxfoYUQwv2nCpfO2HfIa8/D1rMU5zMTqzl UrVGjjFP8fhBeo4BAcKnGHc0KsbeRGNe1rvMwceDTn5p4khbEPEWRQKgUgNFVvJa8J S1EqAdQSM14B/5FkIEvfzjIINi+cwla7U0qoWdtCaWWcYa8UxG6u83ob3As3YjsANb +dv5hKUKpnXMvT+xyhP2BK3wNms3birB9r//n40t7jrzImgLICU1d/79VNfOa90I+w +f2IJUo565VMRqz8vl6L7CvsW7+9ile5spDqEoYwzcDQsZmk1ASzNRDswsFGe3GMYs bNC0Pl/B18tkGOjuaLnUTCfR+utkE/z79Syjr1JlhD6gAxhH99EGj3Y67Jzj/Pup4h EIlJ7nm5slsbPM7VVR/JCOK4fSi4qvg4H9M8iriA/B1D3/L0NzPQandrNxaJ9eIebo uOaMR7qrZ/p1m0VqXf2sJMGY= Received: from zn.tnic (pd953021b.dip0.t-ipconnect.de [217.83.2.27]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature ECDSA (P-256) server-digest SHA256) (No client certificate requested) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 05BF140E0192; Wed, 7 Feb 2024 13:29:27 +0000 (UTC) Date: Wed, 7 Feb 2024 14:29:22 +0100 From: Borislav Petkov To: Ard Biesheuvel Cc: linux-kernel@vger.kernel.org, Ard Biesheuvel , Kevin Loughlin , Tom Lendacky , Dionna Glaze , Thomas Gleixner , Ingo Molnar , Dave Hansen , Andy Lutomirski , Arnd Bergmann , Nathan Chancellor , Nick Desaulniers , Justin Stitt , Kees Cook , Brian Gerst , linux-arch@vger.kernel.org, llvm@lists.linux.dev Subject: Re: [PATCH v3 06/19] x86/startup_64: Drop global variables keeping track of LA57 state Message-ID: <20240207132922.GSZcOFspSGaVluJo92@fat_crate.local> References: <20240129180502.4069817-21-ardb+git@google.com> <20240129180502.4069817-27-ardb+git@google.com> Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20240129180502.4069817-27-ardb+git@google.com> On Mon, Jan 29, 2024 at 07:05:09PM +0100, Ard Biesheuvel wrote: > static inline bool pgtable_l5_enabled(void) > { > return __pgtable_l5_enabled; > } > #else > -#define pgtable_l5_enabled() cpu_feature_enabled(X86_FEATURE_LA57) > +#define pgtable_l5_enabled() !!(native_read_cr4() & X86_CR4_LA57) > #endif /* USE_EARLY_PGTABLE_L5 */ Can we drop this ifdeffery and simply have __pgtable_l5_enabled always present and contain the correct value? So that we don't have an expensive CR4 read hidden in pgtable_l5_enabled()? For the sake of simplicity, pgtable_l5_enabled() can be defined outside of CONFIG_X86_5LEVEL and since both vendors support 5level now, might as well start dropping the CONFIG ifdeffery slowly... Other than that - a nice cleanup! Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette