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Cc:     baolu.lu@linux.intel.com
Subject: Re: [PATCH 1/1] iommu/vt-d: Fix dmar pte read access not set error
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
References: <20191211014015.7898-1-baolu.lu@linux.intel.com>
 <20191212014952.vlrmxrk2cebwxjnp@cantor>
 <6f3bcad9-b9b3-b349-fdad-ce53a79a665b@linux.intel.com>
 <20191213003013.gc3zg3fpzpjntnzg@cantor>
From:   Lu Baolu <baolu.lu@linux.intel.com>
Message-ID: <7d58da5b-3f55-72b2-0638-ae561446d207@linux.intel.com>
Date:   Fri, 13 Dec 2019 10:12:54 +0800
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Hi,

On 12/13/19 8:30 AM, Jerry Snitselaar wrote:
> 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@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>
>>>
>>> Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.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
>>
> 
> I'm testing with this patch, my patch that moves the direct mapping call,
> and Alex's patch for the ISA bridge. It solved the 2 iommu mapping errors
> I was seeing with default passthrough, I no longer see all the dmar pte
> read access errors, and the system boots allowing me to login. I'm tracking
> down 2 issues at the moment. With passthrough I see a problem with 01:00.4
> that I mentioned in the earlier email:
> 
> [   78.978573] uhci_hcd: USB Universal Host Controller Interface driver
> [   78.980842] uhci_hcd 0000:01:00.4: UHCI Host Controller
> [   78.982738] uhci_hcd 0000:01:00.4: new USB bus registered, assigned 
> bus number 3
> [   78.985222] uhci_hcd 0000:01:00.4: detected 8 ports
> [   78.986907] uhci_hcd 0000:01:00.4: port count misdetected? forcing to 
> 2 ports
> [   78.989316] uhci_hcd 0000:01:00.4: irq 16, io base 0x00003c00
> [   78.994634] uhci_hcd 0000:01:00.4: DMAR: 32bit DMA uses non-identity 
> mapping
> [   7 0000:01:00.4: unable to allocate consistent memory for frame list
> [   79.499891] uhci_hcd 0000:01:00.4: startup error -16
> [   79.501588] uhci_hcd 0000:01:00.4: USB bus 3 deregistered
> [   79.503494] uhci_hcd 0000:01:00.4: init 0000:01:00.4 fail, -16
> [   79.505497] uhci_hcd: probe of 0000:01:00.4 failed with error -16
> 
> If I boot the system with iommu=nopt I see an iommu map failure due to
> the prot check in __domain_mapping:
> 
> [   40.940589] pci 0000:00:1f.0: iommu_group_add_device: calling 
> iommu_group_create_direct_mappings
> [   40.943558] pci 0000:00:1f.0: iommu_group_create_direct_mappings: 
> iterating through mappings
> [   40.946402] pci 0000:00:1f.0: iommu_group_create_direct_mappings: 
> calling apply_resv_region
> [   40.949184] pci 0000:00:1f.0: iommu_group_create_direct_mappings: 
> entry type is direct
> [   40.951819] DMAR: intel_iommu_map: enter
> [   40.953128] DMAR: __domain_mapping: prot & 
> (DMA_PTE_READ|DMA_PTE_WRITE) == 0
> [   40.955486] DMAR: domain_mapping: __domain_mapping failed
> [   40.957348] DMAR: intel_iommu_map: domain_pfn_mapping returned -22
> [   40.959466] DMAR: intel_iommu_map: leave
> [   40.959468] iommu: iommu_map: ops->map failed iova 0x0 pa 
> 0x0000000000000000 pgsize 0x1000
> [   40.963511] pci 0000:00:1f.0: iommu_group_create_direct_mappings: 
> iommu_map failed
> [   40.966026] pci 0000:00:1f.0: iommu_group_create_direct_mappings: 
> leaving func
> [   40.968487] pci 0000:00:1f.0: iommu_group_add_device: calling 
> __iommu_attach_device
> [   40.971016] pci 0000:00:1f.0: Adding to iommu group 19
> [   40.972731] pci 0000:00:1f.0: DMAR: domain->type is dma
> 
> /sys/kernel/iommu_groups/19
> [root@hp-dl388g8-07 19]# cat reserved_regions 0x0000000000000000 
> 0x0000000000ffffff direct
> 0x00000000bdf6e000 0x00000000bdf84fff direct
> 0x00000000fee00000 0x00000000feefffff msi
> 
> 00:1f.0 ISA bridge: Intel Corporation C600/X79 series chipset LPC 
> Controller

This seems to be another issue?

Best regards,
baolu