From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (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 7285E20B1E1; Tue, 29 Oct 2024 23:03:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730243027; cv=none; b=mcVL+s4dXxOr2MB8fRvDl0qvmN5+93qU4RnhvAhK9mBDAdGDp9KFExCMQrjPz1XqwBDaAPfyeAwIDKmseS6X45mooo9RMkMj55Irdzt8qQTqnD4NF0FxJQKhuJaXYEpdrUZo+aJIvSmjZwRbjltdyf6FuvsuEnHMeHR01o9gxvU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730243027; c=relaxed/simple; bh=f50WIGB6k8MKzfsAMf7r8sByA9LZjnrApaTM0Y6lrmI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=DDaa1Npn89i7nbLca1575pMoXzNunJGfAFoic55Znu1ObrXJhkceKksn1NlVppAKOZjp/xbR3TJ1FMrVtMtWjeZ0Lg8AbAnhedoc54aX2rMcybga39VTnjs0jc3WXn7x+F8/KgjTUdL3SzziApjk9qMMMLRz5UvDBhCehCCZMC0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=aJTIJb8M; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="aJTIJb8M" Received: from [172.27.3.244] ([76.133.66.138]) (authenticated bits=0) by mail.zytor.com (8.18.1/8.17.1) with ESMTPSA id 49TN2P7E576167 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Tue, 29 Oct 2024 16:02:25 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 49TN2P7E576167 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2024101701; t=1730242949; bh=QkS6mIcMvK7AV9IhJUXopZimVR3qjiZ+/eJ25ztftAQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=aJTIJb8MolXNM4Ur8fRnW/NKuzEbzfOjeSmli0QgYXf0nbD3QCkLFuq9iBg9Fty98 6n7BfcdA9ff8F60jIm356PeSOum9AuRok/6gFZQxNLess6Z6tU7jH5uZIw/xmh0RC4 vAYzZzj5/EdpbzeojU35mljKRWRksi2cGhFd5/4TLF6aVqsYFmvyHH9vJihvwcMpGE 0VnsDZkViUbUeh+QJiHYpZt/4h0eAT+mThHezR6lLhuKS93RBXSobLVfEyfv+UOFiv 5mykH7paFCgrebLadQ2iNXYFa8+n+ywyYTzxqqdocVqk9P3xSO5eKzXtY2f/UBr1IT yAGpxHwvnrPIw== Message-ID: Date: Tue, 29 Oct 2024 16:02:24 -0700 Precedence: bulk X-Mailing-List: linux-efi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 05/16] x86/cpu: Defer CR pinning setup until after EFI initialization To: "Luck, Tony" , "Hansen, Dave" , "Mehta, Sohil" , Alexander Shishkin , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "x86@kernel.org" , Peter Zijlstra , Ard Biesheuvel , "Paul E. McKenney" , Josh Poimboeuf , Xiongwei Song , "Li, Xin3" , "Mike Rapoport (IBM)" , Brijesh Singh , Michael Roth , "Kirill A. Shutemov" , Alexey Kardashevskiy Cc: Jonathan Corbet , Ingo Molnar , Pawan Gupta , Daniel Sneddon , "Huang, Kai" , Sandipan Das , Breno Leitao , "Edgecombe, Rick P" , Alexei Starovoitov , Hou Tao , Juergen Gross , Vegard Nossum , Kees Cook , Eric Biggers , Jason Gunthorpe , "Masami Hiramatsu (Google)" , Andrew Morton , Luis Chamberlain , Yuntao Wang , Rasmus Villemoes , Christophe Leroy , Tejun Heo , Changbin Du , Huang Shijie , Geert Uytterhoeven , Namhyung Kim , Arnaldo Carvalho de Melo , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-efi@vger.kernel.org" References: <20241028160917.1380714-1-alexander.shishkin@linux.intel.com> <20241028160917.1380714-6-alexander.shishkin@linux.intel.com> <34dd023d-3ed5-4655-88be-14a7a300b91e@intel.com> Content-Language: en-US From: "H. Peter Anvin" In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 10/29/24 15:59, Luck, Tony wrote: >> *IF* we switched things to do text poking in the upper half of the >> address space, we'd probably want to find a completely unused PGD entry. >> I'm not sure off the top of my head if we have a good one for that or >> if it's worth the trouble. > > I expect that would be easy on 64-bit (no way the kernel needs all the > PGD entries from 256..511) but hard for 32-bit (where kernel address > space is in critically short supply on any machine with >1GB RAM). No LASS on 32 bits... -hpa