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 DFC702459FD; Fri, 28 Feb 2025 08:24:28 +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=1740731070; cv=none; b=jdAkdRzzcaHZYAWPqVmehBw3Qr/OyTVwmWXH9Jobt/cugCx9I9flWHS6YJ6hMD61Kc5STIHSq2K0vMZXey4quT5T95wHWqzmRwjmVjDL6kBGO+ZFnOUNa1cFmUVbkPGti63YyWimPw3DXU77J/R5NLKt9gERBwahEx6Bz63GrCY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740731070; c=relaxed/simple; bh=HXD5N5EUSKiVZel/nNTVsehaZTF0tGP8+UG+FaEScRg=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Tp6CmC49WnS6sxbWnY+6/0O9cjrIeMzOlBaWDMLNsmUJklFUCzSW1mYd8RrHtpaJIETHazD2/YTb9fMjmfirRUlMm1rfqxbMsqihpaVjhOYh4EidcCG+2+ILISTjttmbv4lpQ0PTAN0QO84Bfp+JwXELKW4tVUKPfdjJw56/j3g= 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=pXU1ZTv6; 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="pXU1ZTv6" 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 51S8NdZV073880 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Fri, 28 Feb 2025 00:23:44 -0800 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 51S8NdZV073880 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2025021701; t=1740731025; bh=wJH2YVKtRVpRZeg1F2uDv6eR5my1DkG7+jj9x2YNq7g=; h=From:To:Cc:Subject:Date:From; b=pXU1ZTv6uV/hcbwru91MHZBY1kks2thOa1n08j0kpmCA2l51euKCBmM1VdMKkke2J J0dI1rcoRmkmEzXzrdyU5bSMNVO/K+Dqg68D28b6I9YQX3maxRc5aNJNjdN6RJSOMA rL8zRThJsVUdkIKdkTa/YHE/hjNk3oThXd3DbL2FzpeEQeQd8xfQBT3VLpwqSu10Du XyRKqfre5Dpz5v4QqZtczCdJ3jW4aUrhMfXfanQnc96rU46B3OKsgXSrFQ15YSA5zB Dm4NNxTKi1xQIPzFIZ5IMmPrNFEoD0Dh5jt0DYzEz88XsprKWVcp3De/Miah/kDW8p QyPTK+6Rns/uQ== 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 Subject: [PATCH v6 0/5] x86/cpufeatures: Automatically generate required and disabled feature masks Date: Fri, 28 Feb 2025 00:23:33 -0800 Message-ID: <20250228082338.73859-1-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 v5: https://lore.kernel.org/lkml/20250106070727.3211006-1-xin@zytor.com/ H. Peter Anvin (Intel) (3): x86/cpufeatures: Rename X86_CMPXCHG64 to X86_CX8 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 | 4 +- arch/x86/Kconfig.cpu | 4 +- arch/x86/Kconfig.cpufeatures | 197 ++++++++++++++++++ arch/x86/Makefile | 17 +- 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/asm-prototypes.h | 2 +- arch/x86/include/asm/atomic64_32.h | 2 +- arch/x86/include/asm/cmpxchg_32.h | 2 +- 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/lib/Makefile | 2 +- arch/x86/lib/cmpxchg8b_emu.S | 2 +- arch/x86/tools/featuremasks.awk | 88 ++++++++ lib/atomic64_test.c | 2 +- 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 - 24 files changed, 320 insertions(+), 634 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: 0b8c04b9207d5ee92ab3b341f0211aaf2c0b6976 -- 2.48.1