From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 047065661; Fri, 16 May 2025 15:46:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747410419; cv=none; b=oOYcvl/2LmJ3cedk/JDJYIK0ZaVMDOJVlje652ZDU34pmDbJ3od+kh+Yg87YIGlNBS7/weh2Wt6z3X3bOUsHY3A6T8ROx6VsaIsjMhTzDUdvsfq50ILoL8Jv9YyiXgF7msKFu2iv8Xk0wldyoVXbgUylkyA10k5WQ7pvhK7reqM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747410419; c=relaxed/simple; bh=mUg2KCJM3nZNLfgyNFElxT8URgyqRgXL21LFChPENMc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=iSNlI3cX8SaU5IIJebR3Ly2TjJR1bpZEjUX9yBGb/soN4pWQ5hD2niox46Qg8HXIGiSzTDlxlYrqD4BV2S1kGnT+L99Q3Tdnvd+8i0Hm9dR6b4Lr1v6dmd8/akc2K2fyoUp0+AezWXVjsVWjAt6VZv6zy05EdKNA7J838QUKZA0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Li3qHaSS; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Li3qHaSS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AE0B6C4CEE4; Fri, 16 May 2025 15:46:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1747410418; bh=mUg2KCJM3nZNLfgyNFElxT8URgyqRgXL21LFChPENMc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Li3qHaSS9TkT6mLcLhYB4VIBNnt5ObMy+G1liN+Z4gP4Um6ezhoLyAkbM7NmhXDuE 9sg+oqlMSzZsRHs55D8CJy/r4o7z6OIaBvbdCcqUJ8qQ34ywTMJZiFD6+MftlFCl6E y/vfvpe+iJshxbogh5k5OOyss2nRXIBmZxwy/QbnFaJyMe13nvmGWoa8NKwKJs4rxs I0MdFbc3/aYparPnNkgh7VN+MENRkCV46inZ9awjeaSCR6Xn8BI2fea7uhusvq/fIa nvO9+zMlKfPg5feoQCTowKyz72zrTfGTaQvRO8LfVG6sYROEeGE+Q16uKGOKC29CxE 3yUjgXprxS7rw== Date: Fri, 16 May 2025 17:46:51 +0200 From: Ingo Molnar To: Borislav Petkov Cc: "Kirill A. Shutemov" , Thomas Gleixner , Ingo Molnar , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Jonathan Corbet , Andy Lutomirski , Peter Zijlstra , Ard Biesheuvel , Jan Kiszka , Kieran Bingham , Michael Roth , Rick Edgecombe , Brijesh Singh , Sandipan Das , Juergen Gross , Tom Lendacky , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-efi@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCHv2 3/3] x86/64/mm: Make 5-level paging support unconditional Message-ID: References: <20250516091534.3414310-1-kirill.shutemov@linux.intel.com> <20250516091534.3414310-4-kirill.shutemov@linux.intel.com> <20250516153009.GEaCdaAdhCVpjaViSx@fat_crate.local> Precedence: bulk X-Mailing-List: linux-efi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250516153009.GEaCdaAdhCVpjaViSx@fat_crate.local> * Borislav Petkov wrote: > On Fri, May 16, 2025 at 12:15:33PM +0300, Kirill A. Shutemov wrote: > > @@ -173,10 +173,10 @@ For example, when an old kernel is running on new hardware. > > The kernel disabled support for it at compile-time > > -------------------------------------------------- > > > > -For example, if 5-level-paging is not enabled when building (i.e., > > -CONFIG_X86_5LEVEL is not selected) the flag "la57" will not show up [#f1]_. > > +For example, if Linear Address Masking (LAM) is not enabled when building (i.e., > > +CONFIG_ADDRESS_MASKING is not selected) the flag "lam" will not show up. > > Even though the feature will still be detected via CPUID, the kernel disables > > -it by clearing via setup_clear_cpu_cap(X86_FEATURE_LA57). > > +it by clearing via setup_clear_cpu_cap(X86_FEATURE_LAM). > > LOL, good one. > > The rest looks nice and good to me. And FWIW, it boots fine on my Zen5 with > 5lvl enabled. > > Reviewed-by: Borislav Petkov (AMD) What's your preference on timing? v6.17 or v6.16? Thanks, Ingo