Re: [PATCH 1/2] iommu/vt-d: Detach domain before using a private one

[Alex Williamson]

On Tue,  6 Aug 2019 08:14:08 +0800
Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> wrote:

> When the default domain of a group doesn't work for a device,
> the iommu driver will try to use a private domain. The domain
> which was previously attached to the device must be detached.
> 
> Cc: Ashok Raj <ashok.raj@xxxxxxxxx>
> Cc: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
> Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
> Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>
> Fixes: 942067f1b6b97 ("iommu/vt-d: Identify default domains replaced with private")
> Reported-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
> Link: https://lkml.org/lkml/2019/8/2/1379
> Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> ---

Tested-by: Alex Williamson <alex.williamson@xxxxxxxxxx>

This series resolves the issue I reported against:
 iommu/vt-d: Cleanup get_valid_domain_for_dev()

Thanks,
Alex

>  drivers/iommu/intel-iommu.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index 3e22fa6ae8c8..37259b7f95a7 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -3449,6 +3449,7 @@ static bool iommu_need_mapping(struct device *dev)
>  				dmar_domain = to_dmar_domain(domain);
>  				dmar_domain->flags |= DOMAIN_FLAG_LOSE_CHILDREN;
>  			}
> +			dmar_remove_one_dev_info(dev);
>  			get_private_domain_for_dev(dev);
>  		}
>  
> @@ -4803,7 +4804,8 @@ static void dmar_remove_one_dev_info(struct device *dev)
>  
>  	spin_lock_irqsave(&device_domain_lock, flags);
>  	info = dev->archdata.iommu;
> -	__dmar_remove_one_dev_info(info);
> +	if (info)
> +		__dmar_remove_one_dev_info(info);
>  	spin_unlock_irqrestore(&device_domain_lock, flags);
>  }
>  
> @@ -5281,6 +5283,7 @@ static int intel_iommu_add_device(struct device *dev)
>  		if (device_def_domain_type(dev) == IOMMU_DOMAIN_IDENTITY) {
>  			ret = iommu_request_dm_for_dev(dev);
>  			if (ret) {
> +				dmar_remove_one_dev_info(dev);
>  				dmar_domain->flags |= DOMAIN_FLAG_LOSE_CHILDREN;
>  				domain_add_dev_info(si_domain, dev);
>  				dev_info(dev,
> @@ -5291,6 +5294,7 @@ static int intel_iommu_add_device(struct device *dev)
>  		if (device_def_domain_type(dev) == IOMMU_DOMAIN_DMA) {
>  			ret = iommu_request_dma_domain_for_dev(dev);
>  			if (ret) {
> +				dmar_remove_one_dev_info(dev);
>  				dmar_domain->flags |= DOMAIN_FLAG_LOSE_CHILDREN;
>  				if (!get_private_domain_for_dev(dev)) {
>  					dev_warn(dev,