diff mbox series

[v2,1/1] PCI: Add translated request only flag for pci_enable_pasid()

Message ID 20230113014409.752405-1-baolu.lu@linux.intel.com
State New
Headers
Series [v2,1/1] PCI: Add translated request only flag for pci_enable_pasid() |

Commit Message

Baolu Lu Jan. 13, 2023, 1:44 a.m. UTC 
  The PCIe fabric routes Memory Requests based on the TLP address, ignoring
the PASID. In order to ensure system integrity, commit 201007ef707a ("PCI:
Enable PASID only when ACS RR & UF enabled on upstream path") requires
some ACS features being supported on device's upstream path when enabling
PCI/PASID.

One alternative is ATS which lets the device resolve the PASID+addr pair
before a memory request is made into a routeable TLB address through the
TA. Those resolved addresses are then cached on the device instead of
in the IOMMU TLB and the device always sets the translated bit for PASID.
One example of those devices are AMD graphic devices that always have ACS
or ATS enabled together with PASID.

This adds a flag parameter in the pci_enable_pasid() helper, with which
the device driver could opt-in the fact that device always sets the
translated bit for PASID.

It also applies this opt-in for AMD graphic devices. Without this change,
kernel boots to black screen on a system with below AMD graphic device:

00:01.0 VGA compatible controller: Advanced Micro Devices, Inc.
        [AMD/ATI] Wani [Radeon R5/R6/R7 Graphics] (rev ca)
        (prog-if 00 [VGA controller])
	DeviceName: ATI EG BROADWAY
	Subsystem: Hewlett-Packard Company Device 8332

At present, it is a common practice to enable/disable PCI PASID in the
iommu drivers. Considering that the device driver knows more about the
specific device, we will follow up by moving pci_enable_pasid() into
the specific device drivers.

Fixes: 201007ef707a ("PCI: Enable PASID only when ACS RR & UF enabled on upstream path")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216865
Reported-by: Matt Fagnani <matt.fagnani@bell.net>
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Suggested-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/pci-ats.h                     | 6 ++++--
 drivers/iommu/amd/iommu.c                   | 2 +-
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 2 +-
 drivers/iommu/intel/iommu.c                 | 3 ++-
 drivers/pci/ats.c                           | 8 ++++++--
 5 files changed, 14 insertions(+), 7 deletions(-)

Change log:
v2:
 - Convert the bool to a named flag;
 - Convert TRANSLED to XLATED.

v1:
 - https://lore.kernel.org/linux-iommu/20230112084629.737653-1-baolu.lu@linux.intel.com/

Comments

Tian, Kevin Jan. 13, 2023, 2:24 a.m. UTC | #1 
> From: Lu Baolu <baolu.lu@linux.intel.com>
> Sent: Friday, January 13, 2023 9:44 AM
> 
> One alternative is ATS which lets the device resolve the PASID+addr pair
> before a memory request is made into a routeable TLB address through the
> TA. Those resolved addresses are then cached on the device instead of
> in the IOMMU TLB and the device always sets the translated bit for PASID.
> One example of those devices are AMD graphic devices that always have ACS
> or ATS enabled together with PASID.

this should be made clear that ATS alone doesn't imply that translated
bit is always set. It's just an optimization so the device may cache
translation for selective requests. Only combining with PRI to
support SVA has such implication.

> + * @flags: device-specific flags
> + *   - PCI_PASID_XLATED_REQ_ONLY: The PCI device only issues PASID
> + *                                memory requests of translated type.

this reads like the device even doesn't issue non-PASID requests.

It is clearer to be "The PCI device always use translated type for all
PASID memory requests".

Otherwise looks good to me:

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Baolu Lu Jan. 13, 2023, 2:36 a.m. UTC | #2 
On 2023/1/13 10:24, Tian, Kevin wrote:
>> From: Lu Baolu <baolu.lu@linux.intel.com>
>> Sent: Friday, January 13, 2023 9:44 AM
>>
>> One alternative is ATS which lets the device resolve the PASID+addr pair
>> before a memory request is made into a routeable TLB address through the
>> TA. Those resolved addresses are then cached on the device instead of
>> in the IOMMU TLB and the device always sets the translated bit for PASID.
>> One example of those devices are AMD graphic devices that always have ACS
>> or ATS enabled together with PASID.
> 
> this should be made clear that ATS alone doesn't imply that translated
> bit is always set. It's just an optimization so the device may cache
> translation for selective requests. Only combining with PRI to
> support SVA has such implication.
> 
>> + * @flags: device-specific flags
>> + *   - PCI_PASID_XLATED_REQ_ONLY: The PCI device only issues PASID
>> + *                                memory requests of translated type.
> 
> this reads like the device even doesn't issue non-PASID requests.
> 
> It is clearer to be "The PCI device always use translated type for all
> PASID memory requests".
> 
> Otherwise looks good to me:
> 
> Reviewed-by: Kevin Tian <kevin.tian@intel.com>

Both make sense to me. It's updated. Thanks a lot!

--
Best regards,
baolu
Matt Fagnani Jan. 13, 2023, 8:15 a.m. UTC | #3 
Baolu,

6.2-rc3 with v2 of this patch applied booted normally without the black 
screen problem. regzbot by Thorsten Leemhuis recommends adding the 
following link tag to the previous discussion at 
https://linux-regtracking.leemhuis.info/regzbot/mainline/ "When fixing, 
add this to the commit message to make regzbot notice patch postings and 
commits to resolve the issue:" Link: 
https://lore.kernel.org/r/15d0f9ff-2a56-b3e9-5b45-e6b23300ae3b@leemhuis.info/ 


Thanks,

Matt

On 1/12/23 20:44, Lu Baolu wrote:
> The PCIe fabric routes Memory Requests based on the TLP address, ignoring
> the PASID. In order to ensure system integrity, commit 201007ef707a ("PCI:
> Enable PASID only when ACS RR & UF enabled on upstream path") requires
> some ACS features being supported on device's upstream path when enabling
> PCI/PASID.
>
> One alternative is ATS which lets the device resolve the PASID+addr pair
> before a memory request is made into a routeable TLB address through the
> TA. Those resolved addresses are then cached on the device instead of
> in the IOMMU TLB and the device always sets the translated bit for PASID.
> One example of those devices are AMD graphic devices that always have ACS
> or ATS enabled together with PASID.
>
> This adds a flag parameter in the pci_enable_pasid() helper, with which
> the device driver could opt-in the fact that device always sets the
> translated bit for PASID.
>
> It also applies this opt-in for AMD graphic devices. Without this change,
> kernel boots to black screen on a system with below AMD graphic device:
>
> 00:01.0 VGA compatible controller: Advanced Micro Devices, Inc.
>          [AMD/ATI] Wani [Radeon R5/R6/R7 Graphics] (rev ca)
>          (prog-if 00 [VGA controller])
> 	DeviceName: ATI EG BROADWAY
> 	Subsystem: Hewlett-Packard Company Device 8332
>
> At present, it is a common practice to enable/disable PCI PASID in the
> iommu drivers. Considering that the device driver knows more about the
> specific device, we will follow up by moving pci_enable_pasid() into
> the specific device drivers.
>
> Fixes: 201007ef707a ("PCI: Enable PASID only when ACS RR & UF enabled on upstream path")
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=216865
> Reported-by: Matt Fagnani <matt.fagnani@bell.net>
> Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
> Suggested-by: Christian König <christian.koenig@amd.com>
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
>   include/linux/pci-ats.h                     | 6 ++++--
>   drivers/iommu/amd/iommu.c                   | 2 +-
>   drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 2 +-
>   drivers/iommu/intel/iommu.c                 | 3 ++-
>   drivers/pci/ats.c                           | 8 ++++++--
>   5 files changed, 14 insertions(+), 7 deletions(-)
>
> Change log:
> v2:
>   - Convert the bool to a named flag;
>   - Convert TRANSLED to XLATED.
>
> v1:
>   - https://lore.kernel.org/linux-iommu/20230112084629.737653-1-baolu.lu@linux.intel.com/
>
> diff --git a/include/linux/pci-ats.h b/include/linux/pci-ats.h
> index df54cd5b15db..750fca736ef4 100644
> --- a/include/linux/pci-ats.h
> +++ b/include/linux/pci-ats.h
> @@ -4,6 +4,8 @@
>   
>   #include <linux/pci.h>
>   
> +#define PCI_PASID_XLATED_REQ_ONLY	BIT(0)
> +
>   #ifdef CONFIG_PCI_ATS
>   /* Address Translation Service */
>   bool pci_ats_supported(struct pci_dev *dev);
> @@ -35,12 +37,12 @@ static inline bool pci_pri_supported(struct pci_dev *pdev)
>   #endif /* CONFIG_PCI_PRI */
>   
>   #ifdef CONFIG_PCI_PASID
> -int pci_enable_pasid(struct pci_dev *pdev, int features);
> +int pci_enable_pasid(struct pci_dev *pdev, int features, int flags);
>   void pci_disable_pasid(struct pci_dev *pdev);
>   int pci_pasid_features(struct pci_dev *pdev);
>   int pci_max_pasids(struct pci_dev *pdev);
>   #else /* CONFIG_PCI_PASID */
> -static inline int pci_enable_pasid(struct pci_dev *pdev, int features)
> +static inline int pci_enable_pasid(struct pci_dev *pdev, int features, int flags)
>   { return -EINVAL; }
>   static inline void pci_disable_pasid(struct pci_dev *pdev) { }
>   static inline int pci_pasid_features(struct pci_dev *pdev)
> diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
> index cbeaab55c0db..64a8c03d7dfa 100644
> --- a/drivers/iommu/amd/iommu.c
> +++ b/drivers/iommu/amd/iommu.c
> @@ -1700,7 +1700,7 @@ static int pdev_pri_ats_enable(struct pci_dev *pdev)
>   	int ret;
>   
>   	/* Only allow access to user-accessible pages */
> -	ret = pci_enable_pasid(pdev, 0);
> +	ret = pci_enable_pasid(pdev, 0, PCI_PASID_XLATED_REQ_ONLY);
>   	if (ret)
>   		goto out_err;
>   
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> index ab160198edd6..891bf53c45dc 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -2350,7 +2350,7 @@ static int arm_smmu_enable_pasid(struct arm_smmu_master *master)
>   	if (num_pasids <= 0)
>   		return num_pasids;
>   
> -	ret = pci_enable_pasid(pdev, features);
> +	ret = pci_enable_pasid(pdev, features, 0);
>   	if (ret) {
>   		dev_err(&pdev->dev, "Failed to enable PASID\n");
>   		return ret;
> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> index 59df7e42fd53..5cc13f02a5ac 100644
> --- a/drivers/iommu/intel/iommu.c
> +++ b/drivers/iommu/intel/iommu.c
> @@ -1425,7 +1425,8 @@ static void iommu_enable_pci_caps(struct device_domain_info *info)
>   	   undefined. So always enable PASID support on devices which
>   	   have it, even if we can't yet know if we're ever going to
>   	   use it. */
> -	if (info->pasid_supported && !pci_enable_pasid(pdev, info->pasid_supported & ~1))
> +	if (info->pasid_supported &&
> +	    !pci_enable_pasid(pdev, info->pasid_supported & ~1, 0))
>   		info->pasid_enabled = 1;
>   
>   	if (info->pri_supported &&
> diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
> index f9cc2e10b676..3a2d9e0ba1d8 100644
> --- a/drivers/pci/ats.c
> +++ b/drivers/pci/ats.c
> @@ -353,12 +353,15 @@ void pci_pasid_init(struct pci_dev *pdev)
>    * pci_enable_pasid - Enable the PASID capability
>    * @pdev: PCI device structure
>    * @features: Features to enable
> + * @flags: device-specific flags
> + *   - PCI_PASID_XLATED_REQ_ONLY: The PCI device only issues PASID
> + *                                memory requests of translated type.
>    *
>    * Returns 0 on success, negative value on error. This function checks
>    * whether the features are actually supported by the device and returns
>    * an error if not.
>    */
> -int pci_enable_pasid(struct pci_dev *pdev, int features)
> +int pci_enable_pasid(struct pci_dev *pdev, int features, int flags)
>   {
>   	u16 control, supported;
>   	int pasid = pdev->pasid_cap;
> @@ -382,7 +385,8 @@ int pci_enable_pasid(struct pci_dev *pdev, int features)
>   	if (!pasid)
>   		return -EINVAL;
>   
> -	if (!pci_acs_path_enabled(pdev, NULL, PCI_ACS_RR | PCI_ACS_UF))
> +	if (!(flags & PCI_PASID_XLATED_REQ_ONLY) &&
> +	    !pci_acs_path_enabled(pdev, NULL, PCI_ACS_RR | PCI_ACS_UF))
>   		return -EINVAL;
>   
>   	pci_read_config_word(pdev, pasid + PCI_PASID_CAP, &supported);
Baolu Lu Jan. 13, 2023, 8:49 a.m. UTC | #4 
On 2023/1/13 16:15, Matt Fagnani wrote:
> Baolu,
> 
> 6.2-rc3 with v2 of this patch applied booted normally without the black 
> screen problem. regzbot by Thorsten Leemhuis recommends adding the 
> following link tag to the previous discussion at 
> https://linux-regtracking.leemhuis.info/regzbot/mainline/ "When fixing, 
> add this to the commit message to make regzbot notice patch postings and 
> commits to resolve the issue:" Link: 
> https://lore.kernel.org/r/15d0f9ff-2a56-b3e9-5b45-e6b23300ae3b@leemhuis.info/

Sure. I will add below:

Fixes: 201007ef707a ("PCI: Enable PASID only when ACS RR & UF enabled on 
upstream path")
Reported-by: Matt Fagnani <matt.fagnani@bell.net>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216865
Link: 
https://lore.kernel.org/r/15d0f9ff-2a56-b3e9-5b45-e6b23300ae3b@leemhuis.info/

By the way, can I add your tested-by?

--
Best regards,
baolu

> 
> Thanks,
> 
> Matt
> 
> On 1/12/23 20:44, Lu Baolu wrote:
>> The PCIe fabric routes Memory Requests based on the TLP address, ignoring
>> the PASID. In order to ensure system integrity, commit 201007ef707a 
>> ("PCI:
>> Enable PASID only when ACS RR & UF enabled on upstream path") requires
>> some ACS features being supported on device's upstream path when enabling
>> PCI/PASID.
>>
>> One alternative is ATS which lets the device resolve the PASID+addr pair
>> before a memory request is made into a routeable TLB address through the
>> TA. Those resolved addresses are then cached on the device instead of
>> in the IOMMU TLB and the device always sets the translated bit for PASID.
>> One example of those devices are AMD graphic devices that always have ACS
>> or ATS enabled together with PASID.
>>
>> This adds a flag parameter in the pci_enable_pasid() helper, with which
>> the device driver could opt-in the fact that device always sets the
>> translated bit for PASID.
>>
>> It also applies this opt-in for AMD graphic devices. Without this change,
>> kernel boots to black screen on a system with below AMD graphic device:
>>
>> 00:01.0 VGA compatible controller: Advanced Micro Devices, Inc.
>>          [AMD/ATI] Wani [Radeon R5/R6/R7 Graphics] (rev ca)
>>          (prog-if 00 [VGA controller])
>>     DeviceName: ATI EG BROADWAY
>>     Subsystem: Hewlett-Packard Company Device 8332
>>
>> At present, it is a common practice to enable/disable PCI PASID in the
>> iommu drivers. Considering that the device driver knows more about the
>> specific device, we will follow up by moving pci_enable_pasid() into
>> the specific device drivers.
>>
>> Fixes: 201007ef707a ("PCI: Enable PASID only when ACS RR & UF enabled 
>> on upstream path")
>> Link: https://bugzilla.kernel.org/show_bug.cgi?id=216865
>> Reported-by: Matt Fagnani <matt.fagnani@bell.net>
>> Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
>> Suggested-by: Christian König <christian.koenig@amd.com>
>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>> ---
>>   include/linux/pci-ats.h                     | 6 ++++--
>>   drivers/iommu/amd/iommu.c                   | 2 +-
>>   drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 2 +-
>>   drivers/iommu/intel/iommu.c                 | 3 ++-
>>   drivers/pci/ats.c                           | 8 ++++++--
>>   5 files changed, 14 insertions(+), 7 deletions(-)
>>
>> Change log:
>> v2:
>>   - Convert the bool to a named flag;
>>   - Convert TRANSLED to XLATED.
>>
>> v1:
>>   - 
>> https://lore.kernel.org/linux-iommu/20230112084629.737653-1-baolu.lu@linux.intel.com/
>>
>> diff --git a/include/linux/pci-ats.h b/include/linux/pci-ats.h
>> index df54cd5b15db..750fca736ef4 100644
>> --- a/include/linux/pci-ats.h
>> +++ b/include/linux/pci-ats.h
>> @@ -4,6 +4,8 @@
>>   #include <linux/pci.h>
>> +#define PCI_PASID_XLATED_REQ_ONLY    BIT(0)
>> +
>>   #ifdef CONFIG_PCI_ATS
>>   /* Address Translation Service */
>>   bool pci_ats_supported(struct pci_dev *dev);
>> @@ -35,12 +37,12 @@ static inline bool pci_pri_supported(struct 
>> pci_dev *pdev)
>>   #endif /* CONFIG_PCI_PRI */
>>   #ifdef CONFIG_PCI_PASID
>> -int pci_enable_pasid(struct pci_dev *pdev, int features);
>> +int pci_enable_pasid(struct pci_dev *pdev, int features, int flags);
>>   void pci_disable_pasid(struct pci_dev *pdev);
>>   int pci_pasid_features(struct pci_dev *pdev);
>>   int pci_max_pasids(struct pci_dev *pdev);
>>   #else /* CONFIG_PCI_PASID */
>> -static inline int pci_enable_pasid(struct pci_dev *pdev, int features)
>> +static inline int pci_enable_pasid(struct pci_dev *pdev, int 
>> features, int flags)
>>   { return -EINVAL; }
>>   static inline void pci_disable_pasid(struct pci_dev *pdev) { }
>>   static inline int pci_pasid_features(struct pci_dev *pdev)
>> diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
>> index cbeaab55c0db..64a8c03d7dfa 100644
>> --- a/drivers/iommu/amd/iommu.c
>> +++ b/drivers/iommu/amd/iommu.c
>> @@ -1700,7 +1700,7 @@ static int pdev_pri_ats_enable(struct pci_dev 
>> *pdev)
>>       int ret;
>>       /* Only allow access to user-accessible pages */
>> -    ret = pci_enable_pasid(pdev, 0);
>> +    ret = pci_enable_pasid(pdev, 0, PCI_PASID_XLATED_REQ_ONLY);
>>       if (ret)
>>           goto out_err;
>> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c 
>> b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
>> index ab160198edd6..891bf53c45dc 100644
>> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
>> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
>> @@ -2350,7 +2350,7 @@ static int arm_smmu_enable_pasid(struct 
>> arm_smmu_master *master)
>>       if (num_pasids <= 0)
>>           return num_pasids;
>> -    ret = pci_enable_pasid(pdev, features);
>> +    ret = pci_enable_pasid(pdev, features, 0);
>>       if (ret) {
>>           dev_err(&pdev->dev, "Failed to enable PASID\n");
>>           return ret;
>> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
>> index 59df7e42fd53..5cc13f02a5ac 100644
>> --- a/drivers/iommu/intel/iommu.c
>> +++ b/drivers/iommu/intel/iommu.c
>> @@ -1425,7 +1425,8 @@ static void iommu_enable_pci_caps(struct 
>> device_domain_info *info)
>>          undefined. So always enable PASID support on devices which
>>          have it, even if we can't yet know if we're ever going to
>>          use it. */
>> -    if (info->pasid_supported && !pci_enable_pasid(pdev, 
>> info->pasid_supported & ~1))
>> +    if (info->pasid_supported &&
>> +        !pci_enable_pasid(pdev, info->pasid_supported & ~1, 0))
>>           info->pasid_enabled = 1;
>>       if (info->pri_supported &&
>> diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
>> index f9cc2e10b676..3a2d9e0ba1d8 100644
>> --- a/drivers/pci/ats.c
>> +++ b/drivers/pci/ats.c
>> @@ -353,12 +353,15 @@ void pci_pasid_init(struct pci_dev *pdev)
>>    * pci_enable_pasid - Enable the PASID capability
>>    * @pdev: PCI device structure
>>    * @features: Features to enable
>> + * @flags: device-specific flags
>> + *   - PCI_PASID_XLATED_REQ_ONLY: The PCI device only issues PASID
>> + *                                memory requests of translated type.
>>    *
>>    * Returns 0 on success, negative value on error. This function checks
>>    * whether the features are actually supported by the device and 
>> returns
>>    * an error if not.
>>    */
>> -int pci_enable_pasid(struct pci_dev *pdev, int features)
>> +int pci_enable_pasid(struct pci_dev *pdev, int features, int flags)
>>   {
>>       u16 control, supported;
>>       int pasid = pdev->pasid_cap;
>> @@ -382,7 +385,8 @@ int pci_enable_pasid(struct pci_dev *pdev, int 
>> features)
>>       if (!pasid)
>>           return -EINVAL;
>> -    if (!pci_acs_path_enabled(pdev, NULL, PCI_ACS_RR | PCI_ACS_UF))
>> +    if (!(flags & PCI_PASID_XLATED_REQ_ONLY) &&
>> +        !pci_acs_path_enabled(pdev, NULL, PCI_ACS_RR | PCI_ACS_UF))
>>           return -EINVAL;
>>       pci_read_config_word(pdev, pasid + PCI_PASID_CAP, &supported);
Matt Fagnani Jan. 13, 2023, 8:51 a.m. UTC | #5 
Baolu,

Yes, you can add the tested-by tag for me.

Thanks,

Matt

On 1/13/23 03:49, Baolu Lu wrote:
> On 2023/1/13 16:15, Matt Fagnani wrote:
>> Baolu,
>>
>> 6.2-rc3 with v2 of this patch applied booted normally without the 
>> black screen problem. regzbot by Thorsten Leemhuis recommends adding 
>> the following link tag to the previous discussion at 
>> https://linux-regtracking.leemhuis.info/regzbot/mainline/ "When 
>> fixing, add this to the commit message to make regzbot notice patch 
>> postings and commits to resolve the issue:" Link: 
>> https://lore.kernel.org/r/15d0f9ff-2a56-b3e9-5b45-e6b23300ae3b@leemhuis.info/
>
> Sure. I will add below:
>
> Fixes: 201007ef707a ("PCI: Enable PASID only when ACS RR & UF enabled 
> on upstream path")
> Reported-by: Matt Fagnani <matt.fagnani@bell.net>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=216865
> Link: 
> https://lore.kernel.org/r/15d0f9ff-2a56-b3e9-5b45-e6b23300ae3b@leemhuis.info/
>
> By the way, can I add your tested-by?
>
> -- 
> Best regards,
> baolu
>
>>
>> Thanks,
>>
>> Matt
>>
>> On 1/12/23 20:44, Lu Baolu wrote:
>>> The PCIe fabric routes Memory Requests based on the TLP address, 
>>> ignoring
>>> the PASID. In order to ensure system integrity, commit 201007ef707a 
>>> ("PCI:
>>> Enable PASID only when ACS RR & UF enabled on upstream path") requires
>>> some ACS features being supported on device's upstream path when 
>>> enabling
>>> PCI/PASID.
>>>
>>> One alternative is ATS which lets the device resolve the PASID+addr 
>>> pair
>>> before a memory request is made into a routeable TLB address through 
>>> the
>>> TA. Those resolved addresses are then cached on the device instead of
>>> in the IOMMU TLB and the device always sets the translated bit for 
>>> PASID.
>>> One example of those devices are AMD graphic devices that always 
>>> have ACS
>>> or ATS enabled together with PASID.
>>>
>>> This adds a flag parameter in the pci_enable_pasid() helper, with which
>>> the device driver could opt-in the fact that device always sets the
>>> translated bit for PASID.
>>>
>>> It also applies this opt-in for AMD graphic devices. Without this 
>>> change,
>>> kernel boots to black screen on a system with below AMD graphic device:
>>>
>>> 00:01.0 VGA compatible controller: Advanced Micro Devices, Inc.
>>>          [AMD/ATI] Wani [Radeon R5/R6/R7 Graphics] (rev ca)
>>>          (prog-if 00 [VGA controller])
>>>     DeviceName: ATI EG BROADWAY
>>>     Subsystem: Hewlett-Packard Company Device 8332
>>>
>>> At present, it is a common practice to enable/disable PCI PASID in the
>>> iommu drivers. Considering that the device driver knows more about the
>>> specific device, we will follow up by moving pci_enable_pasid() into
>>> the specific device drivers.
>>>
>>> Fixes: 201007ef707a ("PCI: Enable PASID only when ACS RR & UF 
>>> enabled on upstream path")
>>> Link: https://bugzilla.kernel.org/show_bug.cgi?id=216865
>>> Reported-by: Matt Fagnani <matt.fagnani@bell.net>
>>> Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
>>> Suggested-by: Christian König <christian.koenig@amd.com>
>>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>>> ---
>>>   include/linux/pci-ats.h                     | 6 ++++--
>>>   drivers/iommu/amd/iommu.c                   | 2 +-
>>>   drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 2 +-
>>>   drivers/iommu/intel/iommu.c                 | 3 ++-
>>>   drivers/pci/ats.c                           | 8 ++++++--
>>>   5 files changed, 14 insertions(+), 7 deletions(-)
>>>
>>> Change log:
>>> v2:
>>>   - Convert the bool to a named flag;
>>>   - Convert TRANSLED to XLATED.
>>>
>>> v1:
>>>   - 
>>> https://lore.kernel.org/linux-iommu/20230112084629.737653-1-baolu.lu@linux.intel.com/
>>>
>>> diff --git a/include/linux/pci-ats.h b/include/linux/pci-ats.h
>>> index df54cd5b15db..750fca736ef4 100644
>>> --- a/include/linux/pci-ats.h
>>> +++ b/include/linux/pci-ats.h
>>> @@ -4,6 +4,8 @@
>>>   #include <linux/pci.h>
>>> +#define PCI_PASID_XLATED_REQ_ONLY    BIT(0)
>>> +
>>>   #ifdef CONFIG_PCI_ATS
>>>   /* Address Translation Service */
>>>   bool pci_ats_supported(struct pci_dev *dev);
>>> @@ -35,12 +37,12 @@ static inline bool pci_pri_supported(struct 
>>> pci_dev *pdev)
>>>   #endif /* CONFIG_PCI_PRI */
>>>   #ifdef CONFIG_PCI_PASID
>>> -int pci_enable_pasid(struct pci_dev *pdev, int features);
>>> +int pci_enable_pasid(struct pci_dev *pdev, int features, int flags);
>>>   void pci_disable_pasid(struct pci_dev *pdev);
>>>   int pci_pasid_features(struct pci_dev *pdev);
>>>   int pci_max_pasids(struct pci_dev *pdev);
>>>   #else /* CONFIG_PCI_PASID */
>>> -static inline int pci_enable_pasid(struct pci_dev *pdev, int features)
>>> +static inline int pci_enable_pasid(struct pci_dev *pdev, int 
>>> features, int flags)
>>>   { return -EINVAL; }
>>>   static inline void pci_disable_pasid(struct pci_dev *pdev) { }
>>>   static inline int pci_pasid_features(struct pci_dev *pdev)
>>> diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
>>> index cbeaab55c0db..64a8c03d7dfa 100644
>>> --- a/drivers/iommu/amd/iommu.c
>>> +++ b/drivers/iommu/amd/iommu.c
>>> @@ -1700,7 +1700,7 @@ static int pdev_pri_ats_enable(struct pci_dev 
>>> *pdev)
>>>       int ret;
>>>       /* Only allow access to user-accessible pages */
>>> -    ret = pci_enable_pasid(pdev, 0);
>>> +    ret = pci_enable_pasid(pdev, 0, PCI_PASID_XLATED_REQ_ONLY);
>>>       if (ret)
>>>           goto out_err;
>>> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c 
>>> b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
>>> index ab160198edd6..891bf53c45dc 100644
>>> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
>>> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
>>> @@ -2350,7 +2350,7 @@ static int arm_smmu_enable_pasid(struct 
>>> arm_smmu_master *master)
>>>       if (num_pasids <= 0)
>>>           return num_pasids;
>>> -    ret = pci_enable_pasid(pdev, features);
>>> +    ret = pci_enable_pasid(pdev, features, 0);
>>>       if (ret) {
>>>           dev_err(&pdev->dev, "Failed to enable PASID\n");
>>>           return ret;
>>> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
>>> index 59df7e42fd53..5cc13f02a5ac 100644
>>> --- a/drivers/iommu/intel/iommu.c
>>> +++ b/drivers/iommu/intel/iommu.c
>>> @@ -1425,7 +1425,8 @@ static void iommu_enable_pci_caps(struct 
>>> device_domain_info *info)
>>>          undefined. So always enable PASID support on devices which
>>>          have it, even if we can't yet know if we're ever going to
>>>          use it. */
>>> -    if (info->pasid_supported && !pci_enable_pasid(pdev, 
>>> info->pasid_supported & ~1))
>>> +    if (info->pasid_supported &&
>>> +        !pci_enable_pasid(pdev, info->pasid_supported & ~1, 0))
>>>           info->pasid_enabled = 1;
>>>       if (info->pri_supported &&
>>> diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
>>> index f9cc2e10b676..3a2d9e0ba1d8 100644
>>> --- a/drivers/pci/ats.c
>>> +++ b/drivers/pci/ats.c
>>> @@ -353,12 +353,15 @@ void pci_pasid_init(struct pci_dev *pdev)
>>>    * pci_enable_pasid - Enable the PASID capability
>>>    * @pdev: PCI device structure
>>>    * @features: Features to enable
>>> + * @flags: device-specific flags
>>> + *   - PCI_PASID_XLATED_REQ_ONLY: The PCI device only issues PASID
>>> + *                                memory requests of translated type.
>>>    *
>>>    * Returns 0 on success, negative value on error. This function 
>>> checks
>>>    * whether the features are actually supported by the device and 
>>> returns
>>>    * an error if not.
>>>    */
>>> -int pci_enable_pasid(struct pci_dev *pdev, int features)
>>> +int pci_enable_pasid(struct pci_dev *pdev, int features, int flags)
>>>   {
>>>       u16 control, supported;
>>>       int pasid = pdev->pasid_cap;
>>> @@ -382,7 +385,8 @@ int pci_enable_pasid(struct pci_dev *pdev, int 
>>> features)
>>>       if (!pasid)
>>>           return -EINVAL;
>>> -    if (!pci_acs_path_enabled(pdev, NULL, PCI_ACS_RR | PCI_ACS_UF))
>>> +    if (!(flags & PCI_PASID_XLATED_REQ_ONLY) &&
>>> +        !pci_acs_path_enabled(pdev, NULL, PCI_ACS_RR | PCI_ACS_UF))
>>>           return -EINVAL;
>>>       pci_read_config_word(pdev, pasid + PCI_PASID_CAP, &supported);
>
Baolu Lu Jan. 14, 2023, 7:45 a.m. UTC | #6 
On 2023/1/13 16:51, Matt Fagnani wrote:
> Baolu,
> 
> Yes, you can add the tested-by tag for me.

Thank you, Matt. I just posted a new version:

https://lore.kernel.org/linux-iommu/20230114073420.759989-1-baolu.lu@linux.intel.com/

--
Best regards,
baolu

> 
> Thanks,
> 
> Matt
> 
> On 1/13/23 03:49, Baolu Lu wrote:
>> On 2023/1/13 16:15, Matt Fagnani wrote:
>>> Baolu,
>>>
>>> 6.2-rc3 with v2 of this patch applied booted normally without the 
>>> black screen problem. regzbot by Thorsten Leemhuis recommends adding 
>>> the following link tag to the previous discussion at 
>>> https://linux-regtracking.leemhuis.info/regzbot/mainline/ "When 
>>> fixing, add this to the commit message to make regzbot notice patch 
>>> postings and commits to resolve the issue:" Link: 
>>> https://lore.kernel.org/r/15d0f9ff-2a56-b3e9-5b45-e6b23300ae3b@leemhuis.info/
>>
>> Sure. I will add below:
>>
>> Fixes: 201007ef707a ("PCI: Enable PASID only when ACS RR & UF enabled 
>> on upstream path")
>> Reported-by: Matt Fagnani <matt.fagnani@bell.net>
>> Link: https://bugzilla.kernel.org/show_bug.cgi?id=216865
>> Link: 
>> https://lore.kernel.org/r/15d0f9ff-2a56-b3e9-5b45-e6b23300ae3b@leemhuis.info/
>>
>> By the way, can I add your tested-by?
>>
>> -- 
>> Best regards,
>> baolu
>>
>>>
>>> Thanks,
>>>
>>> Matt
>>>
>>> On 1/12/23 20:44, Lu Baolu wrote:
>>>> The PCIe fabric routes Memory Requests based on the TLP address, 
>>>> ignoring
>>>> the PASID. In order to ensure system integrity, commit 201007ef707a 
>>>> ("PCI:
>>>> Enable PASID only when ACS RR & UF enabled on upstream path") requires
>>>> some ACS features being supported on device's upstream path when 
>>>> enabling
>>>> PCI/PASID.
>>>>
>>>> One alternative is ATS which lets the device resolve the PASID+addr 
>>>> pair
>>>> before a memory request is made into a routeable TLB address through 
>>>> the
>>>> TA. Those resolved addresses are then cached on the device instead of
>>>> in the IOMMU TLB and the device always sets the translated bit for 
>>>> PASID.
>>>> One example of those devices are AMD graphic devices that always 
>>>> have ACS
>>>> or ATS enabled together with PASID.
>>>>
>>>> This adds a flag parameter in the pci_enable_pasid() helper, with which
>>>> the device driver could opt-in the fact that device always sets the
>>>> translated bit for PASID.
>>>>
>>>> It also applies this opt-in for AMD graphic devices. Without this 
>>>> change,
>>>> kernel boots to black screen on a system with below AMD graphic device:
>>>>
>>>> 00:01.0 VGA compatible controller: Advanced Micro Devices, Inc.
>>>>          [AMD/ATI] Wani [Radeon R5/R6/R7 Graphics] (rev ca)
>>>>          (prog-if 00 [VGA controller])
>>>>     DeviceName: ATI EG BROADWAY
>>>>     Subsystem: Hewlett-Packard Company Device 8332
>>>>
>>>> At present, it is a common practice to enable/disable PCI PASID in the
>>>> iommu drivers. Considering that the device driver knows more about the
>>>> specific device, we will follow up by moving pci_enable_pasid() into
>>>> the specific device drivers.
>>>>
>>>> Fixes: 201007ef707a ("PCI: Enable PASID only when ACS RR & UF 
>>>> enabled on upstream path")
>>>> Link: https://bugzilla.kernel.org/show_bug.cgi?id=216865
>>>> Reported-by: Matt Fagnani <matt.fagnani@bell.net>
>>>> Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
>>>> Suggested-by: Christian König <christian.koenig@amd.com>
>>>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>>>> ---
>>>>   include/linux/pci-ats.h                     | 6 ++++--
>>>>   drivers/iommu/amd/iommu.c                   | 2 +-
>>>>   drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 2 +-
>>>>   drivers/iommu/intel/iommu.c                 | 3 ++-
>>>>   drivers/pci/ats.c                           | 8 ++++++--
>>>>   5 files changed, 14 insertions(+), 7 deletions(-)
>>>>
>>>> Change log:
>>>> v2:
>>>>   - Convert the bool to a named flag;
>>>>   - Convert TRANSLED to XLATED.
>>>>
>>>> v1:
>>>>   - 
>>>> https://lore.kernel.org/linux-iommu/20230112084629.737653-1-baolu.lu@linux.intel.com/
>>>>
>>>> diff --git a/include/linux/pci-ats.h b/include/linux/pci-ats.h
>>>> index df54cd5b15db..750fca736ef4 100644
>>>> --- a/include/linux/pci-ats.h
>>>> +++ b/include/linux/pci-ats.h
>>>> @@ -4,6 +4,8 @@
>>>>   #include <linux/pci.h>
>>>> +#define PCI_PASID_XLATED_REQ_ONLY    BIT(0)
>>>> +
>>>>   #ifdef CONFIG_PCI_ATS
>>>>   /* Address Translation Service */
>>>>   bool pci_ats_supported(struct pci_dev *dev);
>>>> @@ -35,12 +37,12 @@ static inline bool pci_pri_supported(struct 
>>>> pci_dev *pdev)
>>>>   #endif /* CONFIG_PCI_PRI */
>>>>   #ifdef CONFIG_PCI_PASID
>>>> -int pci_enable_pasid(struct pci_dev *pdev, int features);
>>>> +int pci_enable_pasid(struct pci_dev *pdev, int features, int flags);
>>>>   void pci_disable_pasid(struct pci_dev *pdev);
>>>>   int pci_pasid_features(struct pci_dev *pdev);
>>>>   int pci_max_pasids(struct pci_dev *pdev);
>>>>   #else /* CONFIG_PCI_PASID */
>>>> -static inline int pci_enable_pasid(struct pci_dev *pdev, int features)
>>>> +static inline int pci_enable_pasid(struct pci_dev *pdev, int 
>>>> features, int flags)
>>>>   { return -EINVAL; }
>>>>   static inline void pci_disable_pasid(struct pci_dev *pdev) { }
>>>>   static inline int pci_pasid_features(struct pci_dev *pdev)
>>>> diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
>>>> index cbeaab55c0db..64a8c03d7dfa 100644
>>>> --- a/drivers/iommu/amd/iommu.c
>>>> +++ b/drivers/iommu/amd/iommu.c
>>>> @@ -1700,7 +1700,7 @@ static int pdev_pri_ats_enable(struct pci_dev 
>>>> *pdev)
>>>>       int ret;
>>>>       /* Only allow access to user-accessible pages */
>>>> -    ret = pci_enable_pasid(pdev, 0);
>>>> +    ret = pci_enable_pasid(pdev, 0, PCI_PASID_XLATED_REQ_ONLY);
>>>>       if (ret)
>>>>           goto out_err;
>>>> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c 
>>>> b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
>>>> index ab160198edd6..891bf53c45dc 100644
>>>> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
>>>> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
>>>> @@ -2350,7 +2350,7 @@ static int arm_smmu_enable_pasid(struct 
>>>> arm_smmu_master *master)
>>>>       if (num_pasids <= 0)
>>>>           return num_pasids;
>>>> -    ret = pci_enable_pasid(pdev, features);
>>>> +    ret = pci_enable_pasid(pdev, features, 0);
>>>>       if (ret) {
>>>>           dev_err(&pdev->dev, "Failed to enable PASID\n");
>>>>           return ret;
>>>> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
>>>> index 59df7e42fd53..5cc13f02a5ac 100644
>>>> --- a/drivers/iommu/intel/iommu.c
>>>> +++ b/drivers/iommu/intel/iommu.c
>>>> @@ -1425,7 +1425,8 @@ static void iommu_enable_pci_caps(struct 
>>>> device_domain_info *info)
>>>>          undefined. So always enable PASID support on devices which
>>>>          have it, even if we can't yet know if we're ever going to
>>>>          use it. */
>>>> -    if (info->pasid_supported && !pci_enable_pasid(pdev, 
>>>> info->pasid_supported & ~1))
>>>> +    if (info->pasid_supported &&
>>>> +        !pci_enable_pasid(pdev, info->pasid_supported & ~1, 0))
>>>>           info->pasid_enabled = 1;
>>>>       if (info->pri_supported &&
>>>> diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
>>>> index f9cc2e10b676..3a2d9e0ba1d8 100644
>>>> --- a/drivers/pci/ats.c
>>>> +++ b/drivers/pci/ats.c
>>>> @@ -353,12 +353,15 @@ void pci_pasid_init(struct pci_dev *pdev)
>>>>    * pci_enable_pasid - Enable the PASID capability
>>>>    * @pdev: PCI device structure
>>>>    * @features: Features to enable
>>>> + * @flags: device-specific flags
>>>> + *   - PCI_PASID_XLATED_REQ_ONLY: The PCI device only issues PASID
>>>> + *                                memory requests of translated type.
>>>>    *
>>>>    * Returns 0 on success, negative value on error. This function 
>>>> checks
>>>>    * whether the features are actually supported by the device and 
>>>> returns
>>>>    * an error if not.
>>>>    */
>>>> -int pci_enable_pasid(struct pci_dev *pdev, int features)
>>>> +int pci_enable_pasid(struct pci_dev *pdev, int features, int flags)
>>>>   {
>>>>       u16 control, supported;
>>>>       int pasid = pdev->pasid_cap;
>>>> @@ -382,7 +385,8 @@ int pci_enable_pasid(struct pci_dev *pdev, int 
>>>> features)
>>>>       if (!pasid)
>>>>           return -EINVAL;
>>>> -    if (!pci_acs_path_enabled(pdev, NULL, PCI_ACS_RR | PCI_ACS_UF))
>>>> +    if (!(flags & PCI_PASID_XLATED_REQ_ONLY) &&
>>>> +        !pci_acs_path_enabled(pdev, NULL, PCI_ACS_RR | PCI_ACS_UF))
>>>>           return -EINVAL;
>>>>       pci_read_config_word(pdev, pasid + PCI_PASID_CAP, &supported);
>>
>
diff mbox series

Patch

diff --git a/include/linux/pci-ats.h b/include/linux/pci-ats.h
index df54cd5b15db..750fca736ef4 100644
--- a/include/linux/pci-ats.h
+++ b/include/linux/pci-ats.h
@@ -4,6 +4,8 @@ 
 
 #include <linux/pci.h>
 
+#define PCI_PASID_XLATED_REQ_ONLY	BIT(0)
+
 #ifdef CONFIG_PCI_ATS
 /* Address Translation Service */
 bool pci_ats_supported(struct pci_dev *dev);
@@ -35,12 +37,12 @@  static inline bool pci_pri_supported(struct pci_dev *pdev)
 #endif /* CONFIG_PCI_PRI */
 
 #ifdef CONFIG_PCI_PASID
-int pci_enable_pasid(struct pci_dev *pdev, int features);
+int pci_enable_pasid(struct pci_dev *pdev, int features, int flags);
 void pci_disable_pasid(struct pci_dev *pdev);
 int pci_pasid_features(struct pci_dev *pdev);
 int pci_max_pasids(struct pci_dev *pdev);
 #else /* CONFIG_PCI_PASID */
-static inline int pci_enable_pasid(struct pci_dev *pdev, int features)
+static inline int pci_enable_pasid(struct pci_dev *pdev, int features, int flags)
 { return -EINVAL; }
 static inline void pci_disable_pasid(struct pci_dev *pdev) { }
 static inline int pci_pasid_features(struct pci_dev *pdev)
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index cbeaab55c0db..64a8c03d7dfa 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -1700,7 +1700,7 @@  static int pdev_pri_ats_enable(struct pci_dev *pdev)
 	int ret;
 
 	/* Only allow access to user-accessible pages */
-	ret = pci_enable_pasid(pdev, 0);
+	ret = pci_enable_pasid(pdev, 0, PCI_PASID_XLATED_REQ_ONLY);
 	if (ret)
 		goto out_err;
 
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index ab160198edd6..891bf53c45dc 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2350,7 +2350,7 @@  static int arm_smmu_enable_pasid(struct arm_smmu_master *master)
 	if (num_pasids <= 0)
 		return num_pasids;
 
-	ret = pci_enable_pasid(pdev, features);
+	ret = pci_enable_pasid(pdev, features, 0);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to enable PASID\n");
 		return ret;
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 59df7e42fd53..5cc13f02a5ac 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1425,7 +1425,8 @@  static void iommu_enable_pci_caps(struct device_domain_info *info)
 	   undefined. So always enable PASID support on devices which
 	   have it, even if we can't yet know if we're ever going to
 	   use it. */
-	if (info->pasid_supported && !pci_enable_pasid(pdev, info->pasid_supported & ~1))
+	if (info->pasid_supported &&
+	    !pci_enable_pasid(pdev, info->pasid_supported & ~1, 0))
 		info->pasid_enabled = 1;
 
 	if (info->pri_supported &&
diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index f9cc2e10b676..3a2d9e0ba1d8 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -353,12 +353,15 @@  void pci_pasid_init(struct pci_dev *pdev)
  * pci_enable_pasid - Enable the PASID capability
  * @pdev: PCI device structure
  * @features: Features to enable
+ * @flags: device-specific flags
+ *   - PCI_PASID_XLATED_REQ_ONLY: The PCI device only issues PASID
+ *                                memory requests of translated type.
  *
  * Returns 0 on success, negative value on error. This function checks
  * whether the features are actually supported by the device and returns
  * an error if not.
  */
-int pci_enable_pasid(struct pci_dev *pdev, int features)
+int pci_enable_pasid(struct pci_dev *pdev, int features, int flags)
 {
 	u16 control, supported;
 	int pasid = pdev->pasid_cap;
@@ -382,7 +385,8 @@  int pci_enable_pasid(struct pci_dev *pdev, int features)
 	if (!pasid)
 		return -EINVAL;
 
-	if (!pci_acs_path_enabled(pdev, NULL, PCI_ACS_RR | PCI_ACS_UF))
+	if (!(flags & PCI_PASID_XLATED_REQ_ONLY) &&
+	    !pci_acs_path_enabled(pdev, NULL, PCI_ACS_RR | PCI_ACS_UF))
 		return -EINVAL;
 
 	pci_read_config_word(pdev, pasid + PCI_PASID_CAP, &supported);