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 7DFE21DD9AC; Wed, 5 Mar 2025 18:48:33 +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=1741200515; cv=none; b=j6Y+bBTgUxnJeXiTMvxJSVbK7yTOa81M1YBuCPQp8flScD8ZUhXnCvpyh4eW1ut/XO/VWOfuA+pm9bbwXHjfuVfZl+rkn+1th8zcRNLVhCqW7F/bTZB+45ic9B32iavYEYq3gt1qyjLBSqRS3b7TqqLSGm0apCrbTnSTCVd51jU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741200515; c=relaxed/simple; bh=IIRR0j0EA6OllIlVa1v7J4whrRpxr5hO1hZ4BQoMq6s=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=nWRwY7wV4UTgMgvOJoCx1g7KF1MK84Q9wHHP/BHrn4KnVix+mZTggID7bpe3R/bcuROshFr24W95Q701FJz19zLbKAGIIG9xGQfbI2CbOBnyOU8hCcqO0JukG3NqFz9rbrfuaq0qjzbH074ezmUaPXaL+06sJuofN1heWhvWC8c= 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=Fc1mXLoh; 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="Fc1mXLoh" Received: from terminus.zytor.com (terminus.zytor.com [IPv6:2607:7c80:54:3:0:0:0:136]) (authenticated bits=0) by mail.zytor.com (8.18.1/8.17.1) with ESMTPSA id 525IlQXt3341787 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Wed, 5 Mar 2025 10:47:31 -0800 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 525IlQXt3341787 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2025021701; t=1741200452; bh=Kv2mG8/ef/H2lxxHE6kayNM8PX7zHm64gBQrRGDUHAg=; h=From:To:Cc:Subject:Date:From; b=Fc1mXLohNFtkW7wXQe5HLKN/knDyc2mTSzQU061jF/CVHF8z1SAj9Bce3VzPWo8Vf PgDJAAetP/lrw4zp1Ub1yjTfuCDKiyDEHVyPl4/j16wnOLjr/CWmYpZaAipq4QUc4T qs4cxklmepnKVd9bJLmh/4RazVKG7PvNNSeYZcmgAsSoWRndsGXsggwqRW219aDp7m iTjV3MixWSQ3jg5XCU9EFpvE1wkAGnkCey9B6eN1vpGKAG1evU52UUknBQ9Ghm0xy3 /QaQN49vE3So8Hrq1tZkBHQsmDkVmjgj87Us6bUUv/lbYxULxWgSzDwGPQjhAma+yM mRHR87J1ufp1Q== From: "Xin Li (Intel)" To: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, will@kernel.org, peterz@infradead.org, yury.norov@gmail.com, akpm@linux-foundation.org, acme@kernel.org, namhyung@kernel.org, brgerst@gmail.com, andrew.cooper3@citrix.com, nik.borisov@suse.com, sraithal@amd.com, philip.li@intel.com Subject: [PATCH v7 0/4] x86/cpufeatures: Automatically generate required and disabled feature masks Date: Wed, 5 Mar 2025 10:47:20 -0800 Message-ID: <20250305184725.3341760-1-xin@zytor.com> X-Mailer: git-send-email 2.48.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The x86 build process first generates required and disabled feature masks based on current build config, and then uses these generated masks to compile the source code. When a CPU feature is not enabled in a build config, e.g., when CONFIG_X86_FRED=n, its feature disable flag, i.e., DISABLE_FRED, needs to be properly defined and added to a specific disabled CPU features mask in , as the following patch does: https://lore.kernel.org/all/20231205105030.8698-8-xin3.li@intel.com/. As a result, the FRED feature bit is surely cleared in the generated kernel binary when CONFIG_X86_FRED=n. Recently there is another case to repeat the same exercise for the AMD SEV-SNP CPU feature: https://lore.kernel.org/all/20240126041126.1927228-2-michael.roth@amd.com/. https://lore.kernel.org/all/20240126041126.1927228-23-michael.roth@amd.com/. It was one thing when there were four of CPU feature masks, but with over 20 it is going to cause mistakes, e.g., https://lore.kernel.org/lkml/aaed79d5-d683-d1bc-7ba1-b33c8d6db618@suse.com/. We want to eliminate the stupidly repeated exercise to manually assign features to CPU feature words through introducing an AWK script to automatically generate a header with required and disabled CPU feature masks based on current build config, and this patch set does that. Link to v6: https://lore.kernel.org/lkml/20250228082338.73859-1-xin@zytor.com/ Changes in v7: * Fix build error with "make distclean; make headers" (Aithal, Srikanth) * Collect reviewed-bys. H. Peter Anvin (Intel) (2): x86/cpufeatures: Add {required,disabled} feature configs x86/cpufeatures: Generate a feature mask header based on build config Xin Li (Intel) (2): x86/cpufeatures: Remove {disabled,required}-features.h x86/cpufeatures: Use AWK to generate {REQUIRED|DISABLED}_MASK_BIT_SET arch/x86/Kconfig | 2 + arch/x86/Kconfig.cpufeatures | 197 ++++++++++++++++++ arch/x86/Makefile | 15 ++ arch/x86/boot/cpucheck.c | 3 +- arch/x86/boot/cpuflags.c | 1 - arch/x86/boot/mkcpustr.c | 3 +- arch/x86/include/asm/Kbuild | 1 + arch/x86/include/asm/cpufeature.h | 70 +------ arch/x86/include/asm/cpufeatures.h | 8 - arch/x86/include/asm/disabled-features.h | 161 -------------- arch/x86/include/asm/required-features.h | 105 ---------- arch/x86/kernel/verify_cpu.S | 4 + arch/x86/tools/featuremasks.awk | 88 ++++++++ tools/arch/x86/include/asm/cpufeatures.h | 8 - .../arch/x86/include/asm/disabled-features.h | 161 -------------- .../arch/x86/include/asm/required-features.h | 105 ---------- tools/perf/check-headers.sh | 2 - 17 files changed, 311 insertions(+), 623 deletions(-) create mode 100644 arch/x86/Kconfig.cpufeatures delete mode 100644 arch/x86/include/asm/disabled-features.h delete mode 100644 arch/x86/include/asm/required-features.h create mode 100755 arch/x86/tools/featuremasks.awk delete mode 100644 tools/arch/x86/include/asm/disabled-features.h delete mode 100644 tools/arch/x86/include/asm/required-features.h base-commit: 32dc26a2f55f71907af0874468298c6ab8a8f7f9 -- 2.48.1