From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 91FC514E2E6 for ; Tue, 2 Jul 2024 08:25:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719908710; cv=none; b=hy5vfVTpCB3PIgPObGfe7XrTH6m0wMd4j/OSA6CJ3qFrbAdPar4OuWH5ne7S+P6TdfF7z2qMbEmVmO7OAZvn/xlEPPjEEQXV3BH3uW9OSEGXiQt6wOuWYYqMIsw7kwcDg+4/jRSbk7AJq79OxznEzddgEYBm71fQO5LTl+sd4o0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719908710; c=relaxed/simple; bh=nezZaLRQYKczeydaQVqwYcxuR4xq/S/obPHGcjVEAuk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=kzpWk0tMzDyA0taMLppCT+UcB+pJwxj1YyR4zOYcjK378pIhRjfGXBE73Rx/QcGesoEeG9i/Jy1Tld64vpWWh5iaZ+59dS4D5Frm+Qg2M/NZorcg7EooaaN29caPWzycoi3Kj9AlUHPqBBz60sXcrdrQc7AYFSZo6OeDpPHuYjk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=YvTBKuHH; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="YvTBKuHH" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=pDGFpacpgz1Bc31NNapEENaSRx9tG+czkWJu3wz5AHc=; b=YvTBKuHH/XUkl0OKjpxhDFwZfy 0Qo0M5b48lDsTbkVwlwtapKMyL7e6LKhroDnxk2oLzJrSXhCPEbHIO9yLkAHkFjVDGF3HmnXegMSR 03aYXgOKmcp0yeE/dvzxypx0sxYdGlQT9ChWHR9/idl1pyKalqz2Izk1vJdhMz7PAvXaNJ5UCn4yt aL2pNFEIIXuhgFLfC5qc1jbhV9lbL61yTm3CZtNqbRmMoRGrlg5Bgd4io6SUw2/W61Qm3BIiNt7b1 wib2CRbPbPiOZS8usFJxuna/HVTkdoCcHx6Nyy86ekpXxBjDmn/nwsBrQujPUVUY5BCtrakL1ZN9g +4tmm2ag==; Received: from hch by bombadil.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1sOYp3-00000005yxf-0bdG; Tue, 02 Jul 2024 08:25:09 +0000 Date: Tue, 2 Jul 2024 01:25:09 -0700 From: Christoph Hellwig To: Baolu Lu Cc: Christoph Hellwig , David Woodhouse , iommu@lists.linux.dev Subject: Re: lack of permission checking with intel-iommu? Message-ID: References: <4d84afa1-e2ce-4e1b-8fe3-1d3fb0db2ba0@linux.intel.com> Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4d84afa1-e2ce-4e1b-8fe3-1d3fb0db2ba0@linux.intel.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Tue, Jul 02, 2024 at 04:22:25PM +0800, Baolu Lu wrote: > Is it about IOMMU blocking "device reading from buffer" or "device > writing to buffer"? > > The intel iommu driver might use first-stage translation for kernel DMA. > It seems not to block the "device reading from buffer" if I remember it > correctly. This is about device reading from buffer it is only supposed to write to (but doesn't).