linux-kernel - Re: [PATCH 1/1] iommu/vt-d: Fix dmar pte read access not set error

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Message-ID: <20191213054217.sykaftujydkaa4r2@cantor>
Date:   Thu, 12 Dec 2019 22:42:17 -0700
From:   Jerry Snitselaar <jsnitsel@...hat.com>
To:     Lu Baolu <baolu.lu@...ux.intel.com>
Cc:     Joerg Roedel <joro@...tes.org>,
        David Woodhouse <dwmw2@...radead.org>, ashok.raj@...el.com,
        jacob.jun.pan@...el.com, kevin.tian@...el.com,
        iommu@...ts.linux-foundation.org, linux-kernel@...r.kernel.org,
        stable@...r.kernel.org
Subject: Re: [PATCH 1/1] iommu/vt-d: Fix dmar pte read access not set error

On Thu Dec 12 19, Lu Baolu wrote:
>Hi,
>
>On 12/12/19 9:49 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.
>>>
>>>Link: https://www.spinics.net/lists/iommu/msg40416.html
>>>Cc: Jerry Snitselaar <jsnitsel@...hat.com>
>>>Reported-by: Jerry Snitselaar <jsnitsel@...hat.com>
>>>Fixes: 942067f1b6b97 ("iommu/vt-d: Identify default domains 
>>>replaced with private")
>>>Cc: stable@...r.kernel.org # v5.3+
>>>Signed-off-by: Lu Baolu <baolu.lu@...ux.intel.com>
>>
>>Reviewed-by: Jerry Snitselaar <jsnitsel@...hat.com>
>
>Can you please try this fix and check whether it can fix your problem?
>If it helps, do you mind adding a Tested-by?
>
>Best regards,
>baolu
>

Tested-by: Jerry Snitselaar <jsnitsel@...hat.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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