From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.9]) (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 235E723CE for ; Sat, 14 Sep 2024 01:22:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.9 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726276959; cv=none; b=TKzCEl7rJQsMMyEj9hrTHuC/S77vbbVSdr2ZlDjd9Nh+KaZsXrqmEcIBnrlI20nhMAJ2Y5ZarI+2SmBp1x5niMBnm7+QsFYAKisxzVUoWH2Iu3uB09DQ6aRPygViM/piraaxX82q9czrbfktv/2J7hXkidaTp8ifz864aPH2RyM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726276959; c=relaxed/simple; bh=mbnFinhAOf9HlLpqZUuO+D7AGKTVBYcGBW7LKflYPUg=; h=Message-ID:Date:MIME-Version:Cc:Subject:To:References:From: In-Reply-To:Content-Type; b=DUv+fIN3AXb8iQ3jcsiIfP9DUklGTgvWYqEBpH1ZNJOdCTdlNYUn3PQLsHbnaUUUB4kHypkr8Q9SlhCz7WQcvvOyQWj8Ph47yznyKlJ+H3i/CSiu+t4w1cjhvR3RdEV0mvU2Qx/tX5EXuRzs+L8TvWnnvRtIDCgeRFznpRtHLEE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=hnmjKRVJ; arc=none smtp.client-ip=192.198.163.9 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="hnmjKRVJ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1726276958; x=1757812958; h=message-id:date:mime-version:cc:subject:to:references: from:in-reply-to:content-transfer-encoding; bh=mbnFinhAOf9HlLpqZUuO+D7AGKTVBYcGBW7LKflYPUg=; b=hnmjKRVJS2PIQZj1MEgloi0aaJogeN1j+asuUFEUsGqboNu4Pkcb2ZBm Xk9JIcyyDjMgbl1BahsgOS09rXrxo34zuB6TVnwB0TR0v/vatQtw+pc8N S4oM5a2qXtnLJMi4sudMK3mVs+3YpoPmzofpLmqkB0S66+YLLR+SBhvdX y3SzDKY1UYFkHbbTPWIG65drsln8ZiyuOkspVuAQbLA9mGiFauVMxTZz7 m7llis+8njUUyQJ3sgfTGMBerwHbnervw/okmUsV6Af640T+jo+wUiooI A49i5kNf62HkE0/XWgKACwzWBnTVIg5ku4b2uGz0/1UUhCm/XSeQ8JpeP Q==; X-CSE-ConnectionGUID: hNCHMO+FTYaGGksy2bpx0A== X-CSE-MsgGUID: X2yQnt8VRT+QWp5yh19Xbg== X-IronPort-AV: E=McAfee;i="6700,10204,11194"; a="35865440" X-IronPort-AV: E=Sophos;i="6.10,227,1719903600"; d="scan'208";a="35865440" Received: from orviesa010.jf.intel.com ([10.64.159.150]) by fmvoesa103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Sep 2024 18:22:37 -0700 X-CSE-ConnectionGUID: 82VriwB8QO+C4lKPLmjc8A== X-CSE-MsgGUID: 2bUzYFz5QTiMPvELkofjZQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.10,227,1719903600"; d="scan'208";a="68125533" Received: from allen-box.sh.intel.com (HELO [10.239.159.127]) ([10.239.159.127]) by orviesa010.jf.intel.com with ESMTP; 13 Sep 2024 18:22:34 -0700 Message-ID: Date: Sat, 14 Sep 2024 09:18:27 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Cc: baolu.lu@linux.intel.com, "linux-kernel@vger.kernel.org" , "iommu@lists.linux.dev" Subject: Re: [PATCH v2 1/5] iommu/vt-d: Separate page request queue from SVM To: "Tian, Kevin" , "j.granados@samsung.com" , David Woodhouse , Joerg Roedel , Will Deacon , Robin Murphy , Jason Gunthorpe , Klaus Jensen References: <20240913-jag-iopfv8-v2-0-dea01c2343bc@samsung.com> <20240913-jag-iopfv8-v2-1-dea01c2343bc@samsung.com> Content-Language: en-US From: Baolu Lu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 9/14/24 8:52 AM, Tian, Kevin wrote: >> From: Joel Granados via B4 Relay >> >> >> From: Joel Granados >> >> IO page faults are no longer dependent on CONFIG_INTEL_IOMMU_SVM. >> Move >> all Page Request Queue (PRQ) functions that handle prq events to a new >> file in drivers/iommu/intel/prq.c. The page_req_des struct is now >> declared in drivers/iommu/intel/prq.c. >> >> No functional changes are intended. This is a preparation patch to >> enable the use of IO page faults outside the SVM/PASID use cases. > Do we want to guard it under a new config option e.g. > CONFIG_INTEL_IOMMU_IOPF? it's unnecessary to allocate resources > for the majority usages which don't require IOPF. > > Baolu? The OS builder doesn't know if Linux will run on a platform with PRI- capable devices. They'll probably always enable this option if we provide it. This option could be useful for embedded systems, but I'm not sure if any embedded systems have VT-d hardware, which is mainly for high-end PCs or cloud servers. So, maybe we could leave it as is for now and add it later if we see a real use case. Thanks, baolu