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iommu: Fix iommu_probe_device() to attach the right domain

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The general invariant is that all devices in an iommu_group are attached
to group->domain. We missed some cases here where an owned group would not
get the device attached.

Rework this logic so it follows the default domain flow of the
bus_iommu_probe() - call iommu_alloc_default_domain(), then use
__iommu_group_set_domain_internal() to set up all the devices.

Finally always attach the device to the current domain if it is already
set.

This is an unlikely functional issue as iommufd uses iommu_attach_group().
It is possible to hot plug in a new group member, add a vfio driver to it
and then hot add it to an existing iommufd. In this case it is required
that the core code set the iommu_domain properly since iommufd won't call
iommu_attach_group() again.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/9-v5-1b99ae392328+44574-iommu_err_unwind_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Jason Gunthorpe 2023-05-11 01:42:07 -03:00 committed by Joerg Roedel
parent 2f74198ae0
commit e7f85dfbbc
1 changed files with 24 additions and 20 deletions
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44
drivers/iommu/iommu.c
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@ -421,27 +421,31 @@ int iommu_probe_device(struct device *dev)
goto err_release;
}
/*
* Try to allocate a default domain - needs support from the
* IOMMU driver. There are still some drivers which don't
* support default domains, so the return value is not yet
* checked.
*/
mutex_lock(&group->mutex);
iommu_alloc_default_domain(group, dev);
/*
* If device joined an existing group which has been claimed, don't
* attach the default domain.
*/
if (group->default_domain && !group->owner) {
if (group->domain) {
ret = __iommu_device_set_domain(group, dev, group->domain, 0);
if (ret) {
mutex_unlock(&group->mutex);
iommu_group_put(group);
goto err_release;
}
} else if (!group->default_domain) {
/*
* Try to allocate a default domain - needs support from the
* IOMMU driver. There are still some drivers which don't
* support default domains, so the return value is not yet
* checked.
*/
iommu_alloc_default_domain(group, dev);
group->domain = NULL;
if (group->default_domain)
ret = __iommu_group_set_domain(group,
group->default_domain);
/*
* We assume that the iommu driver starts up the device in
* 'set_platform_dma_ops' mode if it does not support default
* domains.
*/
}
if (ret)
goto err_unlock;
iommu_create_device_direct_mappings(group, dev);
@ -454,6 +458,9 @@ int iommu_probe_device(struct device *dev)
return 0;
err_unlock:
mutex_unlock(&group->mutex);
iommu_group_put(group);
err_release:
iommu_release_device(dev);
@ -1665,9 +1672,6 @@ static int iommu_alloc_default_domain(struct iommu_group *group,
{
unsigned int type;
if (group->default_domain)
return 0;
type = iommu_get_def_domain_type(dev) ? : iommu_def_domain_type;
return iommu_group_alloc_default_domain(dev->bus, group, type);