From: Lu Baolu <baolu.lu@linux.intel.com>
To: Joerg Roedel <joro@8bytes.org>,
David Woodhouse <dwmw2@infradead.org>,
ashok.raj@intel.com, jacob.jun.pan@intel.com,
kevin.tian@intel.com, iommu@lists.linux-foundation.org,
linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH 1/1] iommu/vt-d: Fix dmar pte read access not set error
Date: Thu, 12 Dec 2019 09:00:18 +0800 [thread overview]
Message-ID: <86270320-efae-1c37-4c5a-6e5415e36a95@linux.intel.com> (raw)
In-Reply-To: <20191211163511.gjju2s3yy4sus44w@cantor>
Hi,
On 12/12/19 12:35 AM, Jerry Snitselaar wrote:
> On Wed Dec 11 19, Lu Baolu wrote:
>> If the default DMA domain of a group doesn't fit a device, it
>> will still sit in the group but use a private identity domain.
>> When map/unmap/iova_to_phys come through iommu API, the driver
>> should still serve them, otherwise, other devices in the same
>> group will be impacted. Since identity domain has been mapped
>> with the whole available memory space and RMRRs, we don't need
>> to worry about the impact on it.
>>
>
> Does this pose any potential issues with the reverse case where the
> group has a default identity domain, and the first device fits that,
> but a later device in the group needs dma and gets a private dma
> domain?
No. iommu_map/unmap() should not be called for default identity domain.
if (unlikely(!(domain->type & __IOMMU_DOMAIN_PAGING)))
return -EINVAL;
Best regards,
baolu
>
>> Link: https://www.spinics.net/lists/iommu/msg40416.html
>> Cc: Jerry Snitselaar <jsnitsel@redhat.com>
>> Reported-by: Jerry Snitselaar <jsnitsel@redhat.com>
>> Fixes: 942067f1b6b97 ("iommu/vt-d: Identify default domains replaced
>> with private")
>> Cc: stable@vger.kernel.org # v5.3+
>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>> ---
>> drivers/iommu/intel-iommu.c | 8 --------
>> 1 file changed, 8 deletions(-)
>>
>> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
>> index 0c8d81f56a30..b73bebea9148 100644
>> --- a/drivers/iommu/intel-iommu.c
>> +++ b/drivers/iommu/intel-iommu.c
>> @@ -5478,9 +5478,6 @@ static int intel_iommu_map(struct iommu_domain
>> *domain,
>> int prot = 0;
>> int ret;
>>
>> - if (dmar_domain->flags & DOMAIN_FLAG_LOSE_CHILDREN)
>> - return -EINVAL;
>> -
>> if (iommu_prot & IOMMU_READ)
>> prot |= DMA_PTE_READ;
>> if (iommu_prot & IOMMU_WRITE)
>> @@ -5523,8 +5520,6 @@ static size_t intel_iommu_unmap(struct
>> iommu_domain *domain,
>> /* Cope with horrid API which requires us to unmap more than the
>> size argument if it happens to be a large-page mapping. */
>> BUG_ON(!pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level));
>> - if (dmar_domain->flags & DOMAIN_FLAG_LOSE_CHILDREN)
>> - return 0;
>>
>> if (size < VTD_PAGE_SIZE << level_to_offset_bits(level))
>> size = VTD_PAGE_SIZE << level_to_offset_bits(level);
>> @@ -5556,9 +5551,6 @@ static phys_addr_t
>> intel_iommu_iova_to_phys(struct iommu_domain *domain,
>> int level = 0;
>> u64 phys = 0;
>>
>> - if (dmar_domain->flags & DOMAIN_FLAG_LOSE_CHILDREN)
>> - return 0;
>> -
>> pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level);
>> if (pte)
>> phys = dma_pte_addr(pte);
>> --
>> 2.17.1
>>
>
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next prev parent reply other threads:[~2019-12-12 1:01 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-11 1:40 [PATCH 1/1] iommu/vt-d: Fix dmar pte read access not set error Lu Baolu
2019-12-11 16:35 ` Jerry Snitselaar
2019-12-12 1:00 ` Lu Baolu [this message]
2019-12-12 1:49 ` Jerry Snitselaar
2019-12-12 2:12 ` Lu Baolu
2019-12-13 0:30 ` Jerry Snitselaar
2019-12-13 2:12 ` Lu Baolu
2019-12-13 2:51 ` Jerry Snitselaar
2019-12-13 3:16 ` Jerry Snitselaar
2019-12-13 5:01 ` Lu Baolu
2019-12-13 5:42 ` Jerry Snitselaar
2019-12-17 10:28 ` Joerg Roedel
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