From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f200.google.com (mail-pl1-f200.google.com [209.85.214.200]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7E69F322DAF for ; Mon, 20 Jul 2026 19:48:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.200 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784576885; cv=none; b=bS1HsaxonBHBFaRGg9xF9+wz+jR/DWTVgoPJQQov7PlYjHBX8VHmKw0tYPL4jsxSm0GPYKctIpMRgJDXVkurqINwYjF/0UfM3gexchKtnhaKTUEsShSvjTkUzoRxqoPcUMCtx0DWuhUtJLSw+LJuAnzGve36vcMO57wlNK/H4I4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784576885; c=relaxed/simple; bh=jBKIvvcbI3fXVhawc8Ua4dsKdGgdZIBwidjHTIGtinQ=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=FiOMraBaPhEGDeRb3bBmI5LwlHu+hec/nLhmEBb7B62yDFk/YswGYSc5Qsa/KMSxTfyIjnEiRgPCSTb41QqVwZyv+Edpaxu2mWd0HI/A7F6Ftf39Tw1b6u/xeEPZykCw1NQFi0WALd2f0/nAiRT0Im9e27NUIFm3UoQrS5KWIkU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=VaoOWBPU; arc=none smtp.client-ip=209.85.214.200 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="VaoOWBPU" Received: by mail-pl1-f200.google.com with SMTP id d9443c01a7336-2ce8a76df2dso190304385ad.2 for ; Mon, 20 Jul 2026 12:48:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1784576884; x=1785181684; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=zUZr3AoZz7x+rnLocPWr3q7LF0Q0Xt33oDjZwWkJZmQ=; b=VaoOWBPU0bvSbgzwJD86RQScnnt+LuEs1okOlwb+I8RBcbyelf+xd55XjWLeV/FaLB 4maGzEEN7s+QGHZWiomDAVoFS6ojjN8/iZVkHJ4tohpLlqkcaziiB8LnyKC/1pMKToCy KJMuzusXqi9pu81p/du2wEX0TRrm/SDKCDNUaKUNOSV5C137A+rjQscTqOn5D+xhesKX GFQPKId6boQzyZtyJKkRax35bjkx0K9tIhfdfx2dAAl7VoMkmi8Mq9XxZKlVKM2UGWfC zpv8mZQRi1bBQ3L8Aub0kIjoS+WuuO7q3lUSnLSxKXnhYvr8L8wUz0FO1Om5yV7mQMqX dSuw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1784576884; x=1785181684; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=zUZr3AoZz7x+rnLocPWr3q7LF0Q0Xt33oDjZwWkJZmQ=; b=OmZ5tJZj5eHBN4QCiLYa2ZnAwu43Q9w6AvtJ3T8KTwZ//7JxPHXftbLDWmgpjbrx+b dEy31MYrVTkvQVTGth8bAfdmZW1/Rn/QClbRmzpC3zpHD4NDV3NTo3pAjhPjfUynMQqE o2oQ3y1rBbQ9ORnCYd+rm42RievuPZ1fOCW/BLcrDG17IJy+L1jPevO1wD33F4mAlCX3 8iaEQk3mzO1UADq/7rQ9wZzYcK0x+GLnh9lqgE81rhow7rOZVv9d3K9rJzfaAaNsT6Bw 2zRsuEyyWPAgkI25wdwCQn/rPL+Qgwxi8XtI7qbCWNZsG33MqnmVqVEKTOy4OFs7/WyZ bELA== X-Forwarded-Encrypted: i=1; AHgh+RphjXMYhWbaaZQRAqd/YHi6tWbHyIPaY4uGNzYd7MLlYSlWacN2nox3aYZ8Hwf4Nnljm4iN5vUbvt8GEp4=@vger.kernel.org X-Gm-Message-State: AOJu0YweL6VxTxoogdoTNaioTXzKCVF+lT8bobX/gXuAvHRc5IFheGPe GmHZLz0tNldKTSIjMOeDJ1m9tMTWmlbjXKhvxHwmwXYlRzN12Y/nYYynXmrWiZKXzUq+gYoVo03 VN+WE6g== X-Received: from plgn14.prod.google.com ([2002:a17:902:f60e:b0:2ca:ef0c:f8b2]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:902:ce87:b0:2c9:bf82:dd11 with SMTP id d9443c01a7336-2cf34895290mr160220765ad.7.1784576883533; Mon, 20 Jul 2026 12:48:03 -0700 (PDT) Date: Mon, 20 Jul 2026 12:48:02 -0700 In-Reply-To: <20260715224030.3772948-1-jmattson@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260715224030.3772948-1-jmattson@google.com> Message-ID: Subject: Re: [PATCH] x86/cpufeatures: Make AVX512_BMM depend on AVX512F From: Sean Christopherson To: Jim Mattson Cc: x86@kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , Yosry Ahmed , Nikunj A Dadhania , "H . Peter Anvin" , linux-kernel@vger.kernel.org, kvm@vger.kernel.org Content-Type: text/plain; charset="us-ascii" On Wed, Jul 15, 2026, Jim Mattson wrote: > Add an explicit dependency between X86_FEATURE_AVX512_BMM and > X86_FEATURE_AVX512F in the CPUID dependency table. > > AVX512 Bit Matrix Multiply (BMM) instructions operate on vector registers > and require AVX512 Foundation support. Declaring this dependency ensures > that if AVX512F is disabled (e.g. via clearcpuid or host capabilities), > AVX512_BMM will be automatically cleared as well. > > Fixes: de0bfdc7137d ("KVM: x86: Advertise AVX512 Bit Matrix Multiply (BMM) to userspace") > Signed-off-by: Jim Mattson > --- Reviewed-by: Sean Christopherson I assume this will go through the tip tree.