From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.16]) (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 74E629475; Mon, 22 Sep 2025 02:34:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758508493; cv=none; b=aWkPdCTK1Yvex8gD//t2aRVgR/89W97r/zWgoOhSuQ7GaRYz3ps7SQ2ZJlkU/lejb5KqsmTSbHuO1MLKbeLU87NK7amvqHCjrOEiBMU/sn5+LuEbAGLgiyAK4HdAS4jUilRIFAARwVUIThQFNSDj4yXars1HIE8eqDELCJz3E8A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758508493; c=relaxed/simple; bh=wkboUVcjZV+wPCCAmyscZJ148qbyWn9Ptf3UraYhegg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=riuZpyBudt4+JB9/JwTdAF6UJlxlUDDxBpajYb0Ge5EDU8b61VsfT+epN901FYrAMYvAkiRE4OGpj7b+mBINeT4NaBcv2xO5n6bnnbQX/Y+zH4vrn/6qCu0i8u/agOo7WXcYw3WaPDMCSxSsJWqKuGlIRBRXvqXmLWCtSHVmQ10= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=lBdfxogI; arc=none smtp.client-ip=198.175.65.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass 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="lBdfxogI" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1758508492; x=1790044492; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=wkboUVcjZV+wPCCAmyscZJ148qbyWn9Ptf3UraYhegg=; b=lBdfxogIlfZb44CxpVtHdCJzpypzHmkxI+UzDOf5zRtPg6sm4sq+5D87 7+c24S8310JhAhixxd9jzbieu6iFlW95QXTtJyZAAT+HAJym1ITxmiy+T NmX3/IqiaGF1KkPKF52meDp67abiAjtjBwNrFKAGHWGdDgCSrg1kRIWEr FWy8zJekTdOuWiuSAwJcdW19xUrwhclVq4yGNjxFha2cwNVwZ7OCyhn3D EZY2+h6nE2iJZwHvjKjhqZIAAI2YDEaTV84jqoR+67DsarIbBHpFeXmNy 7Itw10uHRrJ1n2fa+jWc1JgPG2H1AB3+XPU/VRXpeoVB21rQeHAl6IBRG A==; X-CSE-ConnectionGUID: fCRdQk9mSc2GLteeofQcjw== X-CSE-MsgGUID: HgTxEb8wSqyePUpvIHpotQ== X-IronPort-AV: E=McAfee;i="6800,10657,11560"; a="60925238" X-IronPort-AV: E=Sophos;i="6.18,284,1751266800"; d="scan'208";a="60925238" Received: from fmviesa007.fm.intel.com ([10.60.135.147]) by orvoesa108.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Sep 2025 19:34:51 -0700 X-CSE-ConnectionGUID: onhjmhx6T+2qjLyTvwK2qw== X-CSE-MsgGUID: BJaNWodNTzigb+06Rj5rcw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.18,284,1751266800"; d="scan'208";a="175959915" Received: from allen-sbox.sh.intel.com (HELO [10.239.159.30]) ([10.239.159.30]) by fmviesa007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Sep 2025 19:34:48 -0700 Message-ID: <00a3fff5-bf1e-461b-9673-14725e3cd6e4@linux.intel.com> Date: Mon, 22 Sep 2025 10:31:49 +0800 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 04/10] iommupt: Flush the CPU cache after any writes to the page table To: Jason Gunthorpe , David Woodhouse , iommu@lists.linux.dev, Joerg Roedel , Robin Murphy , Will Deacon Cc: Kevin Tian , patches@lists.linux.dev, Tina Zhang , Wei Wang References: <4-v2-44d4d9e727e7+18ad8-iommu_pt_vtd_jgg@nvidia.com> Content-Language: en-US From: Baolu Lu In-Reply-To: <4-v2-44d4d9e727e7+18ad8-iommu_pt_vtd_jgg@nvidia.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 8/27/25 01:26, Jason Gunthorpe wrote: > @@ -585,6 +635,7 @@ static __always_inline int __do_map_single_page(struct pt_range *range, > return -EADDRINUSE; > pt_install_leaf_entry(&pts, map->oa, PAGE_SHIFT, > &map->attrs); > + /* No flush, not used when incoherent */ > map->oa += PAGE_SIZE; > return 0; > } > @@ -811,7 +862,8 @@ int DOMAIN_NS(map_pages)(struct iommu_domain *domain, unsigned long iova, > PT_WARN_ON(map.leaf_level > range.top_level); > > do { > - if (single_page) { > + if (single_page && > + !pt_feature(common, PT_FEAT_DMA_INCOHERENT)) { > ret = pt_walk_range(&range, __map_single_page, &map); > if (ret != -EAGAIN) > break; I don't follow the single_page logic here. Why is single_page exclusive with PT_FEAT_DMA_INCOHERENT? To my understanding, PT_FEAT_DMA_INCOHERENT has no relationship with how the page table is organized. Could you elaborate a bit? Thanks, baolu