[v2] iommupt/vtd: Support dirty tracking on PASID

[PATCH v2 1/4] iommu/vt-d: Block PASID attachment to nested domain with dirty tracking

Posted by Zhenzhong Duan 2 days, 13 hours ago

Kernel lacks dirty tracking support on nested domain attached to PASID,
fails the attachment early if nesting parent domain is dirty tracking
configured, otherwise dirty pages would be lost.

Cc: stable@vger.kernel.org
Fixes: f35f22cc760e ("iommu/vt-d: Access/Dirty bit support for SS domains")
Suggested-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
---
 drivers/iommu/intel/nested.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/intel/nested.c b/drivers/iommu/intel/nested.c
index 2b979bec56ce..16c82ba47d30 100644
--- a/drivers/iommu/intel/nested.c
+++ b/drivers/iommu/intel/nested.c
@@ -148,6 +148,7 @@ static int intel_nested_set_dev_pasid(struct iommu_domain *domain,
 {
 	struct device_domain_info *info = dev_iommu_priv_get(dev);
 	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+	struct iommu_domain *s2_domain = &dmar_domain->s2_domain->domain;
 	struct intel_iommu *iommu = info->iommu;
 	struct dev_pasid_info *dev_pasid;
 	int ret;
@@ -155,10 +156,13 @@ static int intel_nested_set_dev_pasid(struct iommu_domain *domain,
 	if (!pasid_supported(iommu) || dev_is_real_dma_subdevice(dev))
 		return -EOPNOTSUPP;
 
+	if (s2_domain->dirty_ops)
+		return -EINVAL;
+
 	if (context_copied(iommu, info->bus, info->devfn))
 		return -EBUSY;
 
-	ret = paging_domain_compatible(&dmar_domain->s2_domain->domain, dev);
+	ret = paging_domain_compatible(s2_domain, dev);
 	if (ret)
 		return ret;
 
-- 
2.47.3

Re: [PATCH v2 1/4] iommu/vt-d: Block PASID attachment to nested domain with dirty tracking

Posted by Yi Liu 1 day, 16 hours ago

On 3/30/26 18:11, Zhenzhong Duan wrote:
> Kernel lacks dirty tracking support on nested domain attached to PASID,
> fails the attachment early if nesting parent domain is dirty tracking
> configured, otherwise dirty pages would be lost.
> 
> Cc: stable@vger.kernel.org
> Fixes: f35f22cc760e ("iommu/vt-d: Access/Dirty bit support for SS domains")
> Suggested-by: Kevin Tian <kevin.tian@intel.com>
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
> ---
>   drivers/iommu/intel/nested.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)

Good catch. Just one nit. I think the below fix tag is more accurate. SS
dirty was merged before PASID attachment. So this fix should be
backported since the first PASID nested domain attachment.

Fixes: 67f6f56b5912 ("iommu/vt-d: Add set_dev_pasid callback for nested 
domain")

Reviewed-by: Yi Liu <yi.l.liu@intel.com>

> diff --git a/drivers/iommu/intel/nested.c b/drivers/iommu/intel/nested.c
> index 2b979bec56ce..16c82ba47d30 100644
> --- a/drivers/iommu/intel/nested.c
> +++ b/drivers/iommu/intel/nested.c
> @@ -148,6 +148,7 @@ static int intel_nested_set_dev_pasid(struct iommu_domain *domain,
>   {
>   	struct device_domain_info *info = dev_iommu_priv_get(dev);
>   	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
> +	struct iommu_domain *s2_domain = &dmar_domain->s2_domain->domain;
>   	struct intel_iommu *iommu = info->iommu;
>   	struct dev_pasid_info *dev_pasid;
>   	int ret;
> @@ -155,10 +156,13 @@ static int intel_nested_set_dev_pasid(struct iommu_domain *domain,
>   	if (!pasid_supported(iommu) || dev_is_real_dma_subdevice(dev))
>   		return -EOPNOTSUPP;
>   
> +	if (s2_domain->dirty_ops)
> +		return -EINVAL;
> +
>   	if (context_copied(iommu, info->bus, info->devfn))
>   		return -EBUSY;
>   
> -	ret = paging_domain_compatible(&dmar_domain->s2_domain->domain, dev);
> +	ret = paging_domain_compatible(s2_domain, dev);
>   	if (ret)
>   		return ret;
>

RE: [PATCH v2 1/4] iommu/vt-d: Block PASID attachment to nested domain with dirty tracking

Posted by Duan, Zhenzhong 15 hours ago


>-----Original Message-----
>From: Liu, Yi L <yi.l.liu@intel.com>
>Subject: Re: [PATCH v2 1/4] iommu/vt-d: Block PASID attachment to nested
>domain with dirty tracking
>
>On 3/30/26 18:11, Zhenzhong Duan wrote:
>> Kernel lacks dirty tracking support on nested domain attached to PASID,
>> fails the attachment early if nesting parent domain is dirty tracking
>> configured, otherwise dirty pages would be lost.
>>
>> Cc: stable@vger.kernel.org
>> Fixes: f35f22cc760e ("iommu/vt-d: Access/Dirty bit support for SS domains")
>> Suggested-by: Kevin Tian <kevin.tian@intel.com>
>> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
>> ---
>>   drivers/iommu/intel/nested.c | 6 +++++-
>>   1 file changed, 5 insertions(+), 1 deletion(-)
>
>Good catch. Just one nit. I think the below fix tag is more accurate. SS
>dirty was merged before PASID attachment. So this fix should be
>backported since the first PASID nested domain attachment.

Oh, I see, thanks for sharing the history.

>
>Fixes: 67f6f56b5912 ("iommu/vt-d: Add set_dev_pasid callback for nested
>domain")

I'll leave it to Baolu to decide if he want a respin or will pick this directly.

BRs,
Zhenzhong

>
>Reviewed-by: Yi Liu <yi.l.liu@intel.com>
>
>> diff --git a/drivers/iommu/intel/nested.c b/drivers/iommu/intel/nested.c
>> index 2b979bec56ce..16c82ba47d30 100644
>> --- a/drivers/iommu/intel/nested.c
>> +++ b/drivers/iommu/intel/nested.c
>> @@ -148,6 +148,7 @@ static int intel_nested_set_dev_pasid(struct
>iommu_domain *domain,
>>   {
>>   	struct device_domain_info *info = dev_iommu_priv_get(dev);
>>   	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
>> +	struct iommu_domain *s2_domain = &dmar_domain->s2_domain-
>>domain;
>>   	struct intel_iommu *iommu = info->iommu;
>>   	struct dev_pasid_info *dev_pasid;
>>   	int ret;
>> @@ -155,10 +156,13 @@ static int intel_nested_set_dev_pasid(struct
>iommu_domain *domain,
>>   	if (!pasid_supported(iommu) || dev_is_real_dma_subdevice(dev))
>>   		return -EOPNOTSUPP;
>>
>> +	if (s2_domain->dirty_ops)
>> +		return -EINVAL;
>> +
>>   	if (context_copied(iommu, info->bus, info->devfn))
>>   		return -EBUSY;
>>
>> -	ret = paging_domain_compatible(&dmar_domain->s2_domain->domain,
>dev);
>> +	ret = paging_domain_compatible(s2_domain, dev);
>>   	if (ret)
>>   		return ret;
>>

RE: [PATCH v2 1/4] iommu/vt-d: Block PASID attachment to nested domain with dirty tracking

Posted by Tian, Kevin 1 day, 16 hours ago

> From: Duan, Zhenzhong <zhenzhong.duan@intel.com>
> Sent: Monday, March 30, 2026 6:11 PM
> 
> Kernel lacks dirty tracking support on nested domain attached to PASID,
> fails the attachment early if nesting parent domain is dirty tracking
> configured, otherwise dirty pages would be lost.
> 
> Cc: stable@vger.kernel.org
> Fixes: f35f22cc760e ("iommu/vt-d: Access/Dirty bit support for SS domains")
> Suggested-by: Kevin Tian <kevin.tian@intel.com>
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>

Reviewed-by: Kevin Tian <kevin.tian@intel.com>