From: Lu Baolu <baolu.lu@linux.intel.com>
To: Jian-Hong Pan <jian-hong@endlessm.com>,
David Woodhouse <dwmw2@infradead.org>,
Joerg Roedel <joro@8bytes.org>
Cc: iommu@lists.linux-foundation.org, linux@endlessm.com,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] iommu/intel-iommu: set as DUMMY_DEVICE_DOMAIN_INFO if no IOMMU
Date: Tue, 4 Feb 2020 14:11:45 +0800 [thread overview]
Message-ID: <aab0948d-c6a3-baa1-7343-f18c936d662d@linux.intel.com> (raw)
In-Reply-To: <20200203091009.196658-1-jian-hong@endlessm.com>
Hi,
On 2020/2/3 17:10, Jian-Hong Pan wrote:
> If the device has no IOMMU, it still invokes iommu_need_mapping during
> intel_alloc_coherent. However, iommu_need_mapping can only check the
> device is DUMMY_DEVICE_DOMAIN_INFO or not. This patch marks the device
> is a DUMMY_DEVICE_DOMAIN_INFO if the device has no IOMMU.
>
> Signed-off-by: Jian-Hong Pan <jian-hong@endlessm.com>
> ---
> drivers/iommu/intel-iommu.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index 35a4a3abedc6..878bc986a015 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -5612,8 +5612,10 @@ static int intel_iommu_add_device(struct device *dev)
> int ret;
>
> iommu = device_to_iommu(dev, &bus, &devfn);
> - if (!iommu)
> + if (!iommu) {
> + dev->archdata.iommu = DUMMY_DEVICE_DOMAIN_INFO;
Is this a DMA capable device? I am afraid some real bugs might be
covered up if we marking the device as IOMMU dummy here.
Best regards,
baolu
> return -ENODEV;
> + }
>
> iommu_device_link(&iommu->iommu, dev);
>
>
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next prev parent reply other threads:[~2020-02-04 6:11 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-03 9:10 [PATCH] iommu/intel-iommu: set as DUMMY_DEVICE_DOMAIN_INFO if no IOMMU Jian-Hong Pan
2020-02-04 6:11 ` Lu Baolu [this message]
2020-02-04 9:25 ` Jian-Hong Pan
2020-02-05 1:28 ` Lu Baolu
2020-02-05 10:06 ` Jian-Hong Pan
2020-02-06 7:25 ` Jian-Hong Pan
2020-02-06 7:32 ` Christoph Hellwig
2020-02-06 10:49 ` Lu Baolu
2020-02-07 7:32 ` Jian-Hong Pan
2020-02-08 6:29 ` Lu Baolu
2020-02-11 9:26 ` Daniel Drake
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