All of lore.kernel.org
 help / color / mirror / Atom feed
From: Christoph Hellwig <hch@lst.de>
To: Lu Baolu <baolu.lu@linux.intel.com>
Cc: alan.cox@intel.com, Christoph Hellwig <hch@lst.de>,
	Stefano Stabellini <sstabellini@kernel.org>,
	ashok.raj@intel.com, Jonathan Corbet <corbet@lwn.net>,
	pengfei.xu@intel.com, Ingo Molnar <mingo@redhat.com>,
	David Woodhouse <dwmw2@infradead.org>,
	kevin.tian@intel.com,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Boris Ostrovsky <boris.ostrovsky@oracle.com>,
	mika.westerberg@linux.intel.com, Juergen Gross <jgross@suse.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
	jacob.jun.pan@intel.com, Robin Murphy <robin.murphy@arm.com>
Subject: Re: [PATCH v5 02/10] iommu/vt-d: Use per-device dma_ops
Date: Tue, 12 Nov 2019 08:16:40 +0100	[thread overview]
Message-ID: <20191112071640.GA3343@lst.de> (raw)
In-Reply-To: <a098359a-0f89-6028-68df-9f83718df256@linux.intel.com>

On Fri, Jul 26, 2019 at 09:56:51AM +0800, Lu Baolu wrote:
> I think current code doesn't do the right thing. The user asks the iommu
> driver to use identity domain for a device, but the driver force it back
> to DMA domain because of the device address capability.
>
>> expensive.  I don't think that this change is a good idea, and even if
>> we decide that this is a good idea after all that should be done in a
>> separate prep patch that explains the rationale.
>
> Yes. Make sense.

Now that the bounce code has landed it might be good time to revisit
this patch in isolation and with a better explanation.
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Lu Baolu <baolu.lu@linux.intel.com>
Cc: Christoph Hellwig <hch@lst.de>,
	David Woodhouse <dwmw2@infradead.org>,
	Joerg Roedel <joro@8bytes.org>,
	Bjorn Helgaas <bhelgaas@google.com>,
	ashok.raj@intel.com, jacob.jun.pan@intel.com, alan.cox@intel.com,
	kevin.tian@intel.com, mika.westerberg@linux.intel.com,
	Ingo Molnar <mingo@redhat.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	pengfei.xu@intel.com,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Robin Murphy <robin.murphy@arm.com>,
	Jonathan Corbet <corbet@lwn.net>,
	Boris Ostrovsky <boris.ostrovsky@oracle.com>,
	Juergen Gross <jgross@suse.com>,
	Stefano Stabellini <sstabellini@kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
	Jacob Pan <jacob.jun.pan@linux.intel.com>
Subject: Re: [PATCH v5 02/10] iommu/vt-d: Use per-device dma_ops
Date: Tue, 12 Nov 2019 08:16:40 +0100	[thread overview]
Message-ID: <20191112071640.GA3343@lst.de> (raw)
In-Reply-To: <a098359a-0f89-6028-68df-9f83718df256@linux.intel.com>

On Fri, Jul 26, 2019 at 09:56:51AM +0800, Lu Baolu wrote:
> I think current code doesn't do the right thing. The user asks the iommu
> driver to use identity domain for a device, but the driver force it back
> to DMA domain because of the device address capability.
>
>> expensive.  I don't think that this change is a good idea, and even if
>> we decide that this is a good idea after all that should be done in a
>> separate prep patch that explains the rationale.
>
> Yes. Make sense.

Now that the bounce code has landed it might be good time to revisit
this patch in isolation and with a better explanation.

  reply	other threads:[~2019-11-12  7:16 UTC|newest]

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-25  3:17 [PATCH v5 00/10] iommu: Bounce page for untrusted devices Lu Baolu
2019-07-25  3:17 ` Lu Baolu
2019-07-25  3:17 ` [PATCH v5 01/10] iommu/vt-d: Don't switch off swiotlb if use direct dma Lu Baolu
2019-07-25  3:17   ` Lu Baolu
2019-07-25  5:41   ` Christoph Hellwig
2019-07-25  5:41     ` Christoph Hellwig
2019-07-25  3:17 ` [PATCH v5 02/10] iommu/vt-d: Use per-device dma_ops Lu Baolu
2019-07-25  3:17   ` Lu Baolu
2019-07-25  5:44   ` Christoph Hellwig
2019-07-25  5:44     ` Christoph Hellwig
2019-07-25  7:18     ` Lu Baolu
2019-07-25  7:18       ` Lu Baolu
2019-07-25 11:43       ` Christoph Hellwig
2019-07-25 11:43         ` Christoph Hellwig
2019-07-26  1:56         ` Lu Baolu
2019-07-26  1:56           ` Lu Baolu
2019-11-12  7:16           ` Christoph Hellwig [this message]
2019-11-12  7:16             ` Christoph Hellwig
2019-11-13  2:50             ` Lu Baolu
2019-11-13  2:50               ` Lu Baolu
2019-11-13  7:03               ` Christoph Hellwig
2019-11-13  7:03                 ` Christoph Hellwig
2019-11-13  9:53                 ` Christoph Hellwig
2019-11-13  9:53                   ` Christoph Hellwig
2019-11-14  5:14                   ` Lu Baolu
2019-11-14  5:14                     ` Lu Baolu
2019-11-14  8:14                     ` Christoph Hellwig
2019-11-14  8:14                       ` Christoph Hellwig
2019-11-15  0:57                       ` Lu Baolu
2019-11-20 10:44                         ` Christoph Hellwig
2019-07-25  3:17 ` [PATCH v5 03/10] iommu/vt-d: Cleanup after use per-device dma ops Lu Baolu
2019-07-25  3:17   ` Lu Baolu
2019-07-25  3:17 ` [PATCH v5 04/10] PCI: Add dev_is_untrusted helper Lu Baolu
2019-07-25  3:17   ` Lu Baolu
2019-07-25  5:44   ` Christoph Hellwig
2019-07-25  5:44     ` Christoph Hellwig
2019-07-25  3:17 ` [PATCH v5 05/10] swiotlb: Split size parameter to map/unmap APIs Lu Baolu
2019-07-25  3:17   ` Lu Baolu
2019-07-25 11:47   ` Christoph Hellwig
2019-07-25 11:47     ` Christoph Hellwig
2019-07-25  3:17 ` [PATCH v5 06/10] swiotlb: Zero out bounce buffer for untrusted device Lu Baolu
2019-07-25  3:17   ` Lu Baolu
2019-07-25 11:49   ` Christoph Hellwig
2019-07-25 11:49     ` Christoph Hellwig
2019-07-26  2:21     ` Lu Baolu
2019-07-26  2:21       ` Lu Baolu
2019-07-25  3:17 ` [PATCH v5 07/10] iommu: Add bounce page APIs Lu Baolu
2019-07-25  3:17   ` Lu Baolu
2019-07-25  3:17 ` [PATCH v5 08/10] iommu/vt-d: Check whether device requires bounce buffer Lu Baolu
2019-07-25  3:17   ` Lu Baolu
2019-07-25  3:17 ` [PATCH v5 09/10] iommu/vt-d: Add trace events for device dma map/unmap Lu Baolu
2019-07-25  3:17   ` Lu Baolu
2019-07-25 12:26   ` Steven Rostedt
2019-07-25 12:26     ` Steven Rostedt
2019-07-26  2:24     ` Lu Baolu
2019-07-26  2:24       ` Lu Baolu
2019-07-25  3:17 ` [PATCH v5 10/10] iommu/vt-d: Use bounce buffer for untrusted devices Lu Baolu
2019-07-25  3:17   ` Lu Baolu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20191112071640.GA3343@lst.de \
    --to=hch@lst.de \
    --cc=alan.cox@intel.com \
    --cc=ashok.raj@intel.com \
    --cc=baolu.lu@linux.intel.com \
    --cc=bhelgaas@google.com \
    --cc=boris.ostrovsky@oracle.com \
    --cc=corbet@lwn.net \
    --cc=dwmw2@infradead.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=iommu@lists.linux-foundation.org \
    --cc=jacob.jun.pan@intel.com \
    --cc=jgross@suse.com \
    --cc=kevin.tian@intel.com \
    --cc=konrad.wilk@oracle.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mika.westerberg@linux.intel.com \
    --cc=mingo@redhat.com \
    --cc=pengfei.xu@intel.com \
    --cc=robin.murphy@arm.com \
    --cc=rostedt@goodmis.org \
    --cc=sstabellini@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.