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Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/…
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…git/jgg/iommufd.git
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Stephen Rothwell committed Mar 20, 2023
2 parents 301b051 + 4ed4791 commit 2f5699b
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Showing 8 changed files with 369 additions and 209 deletions.
149 changes: 47 additions & 102 deletions drivers/iommu/iommufd/device.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -15,31 +15,15 @@ MODULE_PARM_DESC(
"Allow IOMMUFD to bind to devices even if the platform cannot isolate "
"the MSI interrupt window. Enabling this is a security weakness.");

/*
* A iommufd_device object represents the binding relationship between a
* consuming driver and the iommufd. These objects are created/destroyed by
* external drivers, not by userspace.
*/
struct iommufd_device {
struct iommufd_object obj;
struct iommufd_ctx *ictx;
struct iommufd_hw_pagetable *hwpt;
/* Head at iommufd_hw_pagetable::devices */
struct list_head devices_item;
/* always the physical device */
struct device *dev;
struct iommu_group *group;
bool enforce_cache_coherency;
};

void iommufd_device_destroy(struct iommufd_object *obj)
{
struct iommufd_device *idev =
container_of(obj, struct iommufd_device, obj);

iommu_device_release_dma_owner(idev->dev);
iommu_group_put(idev->group);
iommufd_ctx_put(idev->ictx);
if (!iommufd_selftest_is_mock_dev(idev->dev))
iommufd_ctx_put(idev->ictx);
}

/**
Expand Down Expand Up @@ -86,7 +70,8 @@ struct iommufd_device *iommufd_device_bind(struct iommufd_ctx *ictx,
goto out_release_owner;
}
idev->ictx = ictx;
iommufd_ctx_get(ictx);
if (!iommufd_selftest_is_mock_dev(dev))
iommufd_ctx_get(ictx);
idev->dev = dev;
idev->enforce_cache_coherency =
device_iommu_capable(dev, IOMMU_CAP_ENFORCE_CACHE_COHERENCY);
Expand Down Expand Up @@ -168,7 +153,8 @@ static int iommufd_device_setup_msi(struct iommufd_device *idev,
* operation from the device (eg a simple DMA) cannot trigger an
* interrupt outside this iommufd context.
*/
if (!iommu_group_has_isolated_msi(idev->group)) {
if (!iommufd_selftest_is_mock_dev(idev->dev) &&
!iommu_group_has_isolated_msi(idev->group)) {
if (!allow_unsafe_interrupts)
return -EPERM;

Expand All @@ -186,19 +172,24 @@ static bool iommufd_hw_pagetable_has_group(struct iommufd_hw_pagetable *hwpt,
{
struct iommufd_device *cur_dev;

lockdep_assert_held(&hwpt->devices_lock);

list_for_each_entry(cur_dev, &hwpt->devices, devices_item)
if (cur_dev->group == group)
return true;
return false;
}

static int iommufd_device_do_attach(struct iommufd_device *idev,
struct iommufd_hw_pagetable *hwpt)
int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt,
struct iommufd_device *idev)
{
phys_addr_t sw_msi_start = PHYS_ADDR_MAX;
int rc;

mutex_lock(&hwpt->devices_lock);
lockdep_assert_held(&hwpt->devices_lock);

if (WARN_ON(idev->hwpt))
return -EINVAL;

/*
* Try to upgrade the domain we have, it is an iommu driver bug to
Expand All @@ -213,19 +204,18 @@ static int iommufd_device_do_attach(struct iommufd_device *idev,
hwpt->domain);
if (!hwpt->enforce_cache_coherency) {
WARN_ON(list_empty(&hwpt->devices));
rc = -EINVAL;
goto out_unlock;
return -EINVAL;
}
}

rc = iopt_table_enforce_group_resv_regions(&hwpt->ioas->iopt, idev->dev,
idev->group, &sw_msi_start);
if (rc)
goto out_unlock;
return rc;

rc = iommufd_device_setup_msi(idev, hwpt, sw_msi_start);
if (rc)
goto out_iova;
goto err_unresv;

/*
* FIXME: Hack around missing a device-centric iommu api, only attach to
Expand All @@ -234,26 +224,35 @@ static int iommufd_device_do_attach(struct iommufd_device *idev,
if (!iommufd_hw_pagetable_has_group(hwpt, idev->group)) {
rc = iommu_attach_group(hwpt->domain, idev->group);
if (rc)
goto out_iova;

if (list_empty(&hwpt->devices)) {
rc = iopt_table_add_domain(&hwpt->ioas->iopt,
hwpt->domain);
if (rc)
goto out_detach;
}
goto err_unresv;
}
return 0;
err_unresv:
iopt_remove_reserved_iova(&hwpt->ioas->iopt, idev->dev);
return rc;
}

void iommufd_hw_pagetable_detach(struct iommufd_hw_pagetable *hwpt,
struct iommufd_device *idev)
{
if (!iommufd_hw_pagetable_has_group(hwpt, idev->group))
iommu_detach_group(hwpt->domain, idev->group);
iopt_remove_reserved_iova(&hwpt->ioas->iopt, idev->dev);
}

static int iommufd_device_do_attach(struct iommufd_device *idev,
struct iommufd_hw_pagetable *hwpt)
{
int rc;

mutex_lock(&hwpt->devices_lock);
rc = iommufd_hw_pagetable_attach(hwpt, idev);
if (rc)
goto out_unlock;

idev->hwpt = hwpt;
refcount_inc(&hwpt->obj.users);
list_add(&idev->devices_item, &hwpt->devices);
mutex_unlock(&hwpt->devices_lock);
return 0;

out_detach:
iommu_detach_group(hwpt->domain, idev->group);
out_iova:
iopt_remove_reserved_iova(&hwpt->ioas->iopt, idev->dev);
out_unlock:
mutex_unlock(&hwpt->devices_lock);
return rc;
Expand All @@ -280,7 +279,10 @@ static int iommufd_device_auto_get_domain(struct iommufd_device *idev,
if (!hwpt->auto_domain)
continue;

if (!iommufd_lock_obj(&hwpt->obj))
continue;
rc = iommufd_device_do_attach(idev, hwpt);
iommufd_put_object(&hwpt->obj);

/*
* -EINVAL means the domain is incompatible with the device.
Expand All @@ -292,24 +294,16 @@ static int iommufd_device_auto_get_domain(struct iommufd_device *idev,
goto out_unlock;
}

hwpt = iommufd_hw_pagetable_alloc(idev->ictx, ioas, idev->dev);
hwpt = iommufd_hw_pagetable_alloc(idev->ictx, ioas, idev, true);
if (IS_ERR(hwpt)) {
rc = PTR_ERR(hwpt);
goto out_unlock;
}
hwpt->auto_domain = true;

rc = iommufd_device_do_attach(idev, hwpt);
if (rc)
goto out_abort;
list_add_tail(&hwpt->hwpt_item, &ioas->hwpt_list);

mutex_unlock(&ioas->mutex);
iommufd_object_finalize(idev->ictx, &hwpt->obj);
return 0;

out_abort:
iommufd_object_abort_and_destroy(idev->ictx, &hwpt->obj);
out_unlock:
mutex_unlock(&ioas->mutex);
return rc;
Expand Down Expand Up @@ -381,28 +375,17 @@ void iommufd_device_detach(struct iommufd_device *idev)
{
struct iommufd_hw_pagetable *hwpt = idev->hwpt;

mutex_lock(&hwpt->ioas->mutex);
mutex_lock(&hwpt->devices_lock);
list_del(&idev->devices_item);
if (!iommufd_hw_pagetable_has_group(hwpt, idev->group)) {
if (list_empty(&hwpt->devices)) {
iopt_table_remove_domain(&hwpt->ioas->iopt,
hwpt->domain);
list_del(&hwpt->hwpt_item);
}
iommu_detach_group(hwpt->domain, idev->group);
}
iopt_remove_reserved_iova(&hwpt->ioas->iopt, idev->dev);
idev->hwpt = NULL;
iommufd_hw_pagetable_detach(hwpt, idev);
mutex_unlock(&hwpt->devices_lock);
mutex_unlock(&hwpt->ioas->mutex);

if (hwpt->auto_domain)
iommufd_object_destroy_user(idev->ictx, &hwpt->obj);
else
refcount_dec(&hwpt->obj.users);

idev->hwpt = NULL;

refcount_dec(&idev->obj.users);
}
EXPORT_SYMBOL_NS_GPL(iommufd_device_detach, IOMMUFD);
Expand Down Expand Up @@ -726,41 +709,3 @@ int iommufd_access_rw(struct iommufd_access *access, unsigned long iova,
return rc;
}
EXPORT_SYMBOL_NS_GPL(iommufd_access_rw, IOMMUFD);

#ifdef CONFIG_IOMMUFD_TEST
/*
* Creating a real iommufd_device is too hard, bypass creating a iommufd_device
* and go directly to attaching a domain.
*/
struct iommufd_hw_pagetable *
iommufd_device_selftest_attach(struct iommufd_ctx *ictx,
struct iommufd_ioas *ioas,
struct device *mock_dev)
{
struct iommufd_hw_pagetable *hwpt;
int rc;

hwpt = iommufd_hw_pagetable_alloc(ictx, ioas, mock_dev);
if (IS_ERR(hwpt))
return hwpt;

rc = iopt_table_add_domain(&hwpt->ioas->iopt, hwpt->domain);
if (rc)
goto out_hwpt;

refcount_inc(&hwpt->obj.users);
iommufd_object_finalize(ictx, &hwpt->obj);
return hwpt;

out_hwpt:
iommufd_object_abort_and_destroy(ictx, &hwpt->obj);
return ERR_PTR(rc);
}

void iommufd_device_selftest_detach(struct iommufd_ctx *ictx,
struct iommufd_hw_pagetable *hwpt)
{
iopt_table_remove_domain(&hwpt->ioas->iopt, hwpt->domain);
refcount_dec(&hwpt->obj.users);
}
#endif
70 changes: 59 additions & 11 deletions drivers/iommu/iommufd/hw_pagetable.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -13,7 +13,17 @@ void iommufd_hw_pagetable_destroy(struct iommufd_object *obj)

WARN_ON(!list_empty(&hwpt->devices));

iommu_domain_free(hwpt->domain);
if (!list_empty(&hwpt->hwpt_item)) {
mutex_lock(&hwpt->ioas->mutex);
list_del(&hwpt->hwpt_item);
mutex_unlock(&hwpt->ioas->mutex);

iopt_table_remove_domain(&hwpt->ioas->iopt, hwpt->domain);
}

if (hwpt->domain)
iommu_domain_free(hwpt->domain);

refcount_dec(&hwpt->ioas->obj.users);
mutex_destroy(&hwpt->devices_lock);
}
Expand All @@ -22,36 +32,74 @@ void iommufd_hw_pagetable_destroy(struct iommufd_object *obj)
* iommufd_hw_pagetable_alloc() - Get an iommu_domain for a device
* @ictx: iommufd context
* @ioas: IOAS to associate the domain with
* @dev: Device to get an iommu_domain for
* @idev: Device to get an iommu_domain for
* @immediate_attach: True if idev should be attached to the hwpt
*
* Allocate a new iommu_domain and return it as a hw_pagetable.
* Allocate a new iommu_domain and return it as a hw_pagetable. The HWPT
* will be linked to the given ioas and upon return the underlying iommu_domain
* is fully popoulated.
*/
struct iommufd_hw_pagetable *
iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
struct device *dev)
struct iommufd_device *idev, bool immediate_attach)
{
struct iommufd_hw_pagetable *hwpt;
int rc;

lockdep_assert_held(&ioas->mutex);

hwpt = iommufd_object_alloc(ictx, hwpt, IOMMUFD_OBJ_HW_PAGETABLE);
if (IS_ERR(hwpt))
return hwpt;

hwpt->domain = iommu_domain_alloc(dev->bus);
if (!hwpt->domain) {
rc = -ENOMEM;
goto out_abort;
}

INIT_LIST_HEAD(&hwpt->devices);
INIT_LIST_HEAD(&hwpt->hwpt_item);
mutex_init(&hwpt->devices_lock);
/* Pairs with iommufd_hw_pagetable_destroy() */
refcount_inc(&ioas->obj.users);
hwpt->ioas = ioas;

hwpt->domain = iommu_domain_alloc(idev->dev->bus);
if (!hwpt->domain) {
rc = -ENOMEM;
goto out_abort;
}

mutex_lock(&hwpt->devices_lock);

/*
* immediate_attach exists only to accommodate iommu drivers that cannot
* directly allocate a domain. These drivers do not finish creating the
* domain until attach is completed. Thus we must have this call
* sequence. Once those drivers are fixed this should be removed.
*/
if (immediate_attach) {
rc = iommufd_hw_pagetable_attach(hwpt, idev);
if (rc)
goto out_unlock;
}

rc = iopt_table_add_domain(&hwpt->ioas->iopt, hwpt->domain);
if (rc)
goto out_detach;
list_add_tail(&hwpt->hwpt_item, &hwpt->ioas->hwpt_list);

if (immediate_attach) {
/* See iommufd_device_do_attach() */
refcount_inc(&hwpt->obj.users);
idev->hwpt = hwpt;
list_add(&idev->devices_item, &hwpt->devices);
}

mutex_unlock(&hwpt->devices_lock);
return hwpt;

out_detach:
if (immediate_attach)
iommufd_hw_pagetable_detach(hwpt, idev);
out_unlock:
mutex_unlock(&hwpt->devices_lock);
out_abort:
iommufd_object_abort(ictx, &hwpt->obj);
iommufd_object_abort_and_destroy(ictx, &hwpt->obj);
return ERR_PTR(rc);
}
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