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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: Thu, 25 Jul 2019 07:44:13 +0200	[thread overview]
Message-ID: <20190725054413.GC24527@lst.de> (raw)
In-Reply-To: <20190725031717.32317-3-baolu.lu@linux.intel.com>

>  /* Check if the dev needs to go through non-identity map and unmap process.*/
>  static bool iommu_need_mapping(struct device *dev)
>  {
> -	int ret;
> -
>  	if (iommu_dummy(dev))
>  		return false;
>  
> -	ret = identity_mapping(dev);
> -	if (ret) {
> -		u64 dma_mask = *dev->dma_mask;
> -
> -		if (dev->coherent_dma_mask && dev->coherent_dma_mask < dma_mask)
> -			dma_mask = dev->coherent_dma_mask;
> -
> -		if (dma_mask >= dma_get_required_mask(dev))
> -			return false;

Don't we need to keep this bit so that we still allow the IOMMU
to act if the device has a too small DMA mask to address all memory in
the system, even if if it should otherwise be identity mapped?
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WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Lu Baolu <baolu.lu@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>,
	Joerg Roedel <joro@8bytes.org>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Christoph Hellwig <hch@lst.de>,
	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: Thu, 25 Jul 2019 07:44:13 +0200	[thread overview]
Message-ID: <20190725054413.GC24527@lst.de> (raw)
In-Reply-To: <20190725031717.32317-3-baolu.lu@linux.intel.com>

>  /* Check if the dev needs to go through non-identity map and unmap process.*/
>  static bool iommu_need_mapping(struct device *dev)
>  {
> -	int ret;
> -
>  	if (iommu_dummy(dev))
>  		return false;
>  
> -	ret = identity_mapping(dev);
> -	if (ret) {
> -		u64 dma_mask = *dev->dma_mask;
> -
> -		if (dev->coherent_dma_mask && dev->coherent_dma_mask < dma_mask)
> -			dma_mask = dev->coherent_dma_mask;
> -
> -		if (dma_mask >= dma_get_required_mask(dev))
> -			return false;

Don't we need to keep this bit so that we still allow the IOMMU
to act if the device has a too small DMA mask to address all memory in
the system, even if if it should otherwise be identity mapped?

  reply	other threads:[~2019-07-25  5:44 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 [this message]
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
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

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