> From: Christoph Hellwig <hch@xxxxxx>
> Sent: Thursday, August 26, 2021 12:19 AM
>
> The iommu_device field in struct mdev_device has never been used
> since it was added more than 2 years ago.
>
> This is a manual revert of commit 7bd50f0cd2
> ("vfio/type1: Add domain at(de)taching group helpers").
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
> ---
> drivers/vfio/vfio_iommu_type1.c | 133 +++++++-------------------------
> include/linux/mdev.h | 20 -----
> 2 files changed, 26 insertions(+), 127 deletions(-)
>
> diff --git a/drivers/vfio/vfio_iommu_type1.c
> b/drivers/vfio/vfio_iommu_type1.c
> index 92777797578e50..39e2706d0b3f34 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -114,7 +114,6 @@ struct vfio_batch {
> struct vfio_iommu_group {
> struct iommu_group *iommu_group;
> struct list_head next;
> - bool mdev_group; /* An mdev group */
> bool pinned_page_dirty_scope;
> };
>
> @@ -1935,61 +1934,6 @@ static bool vfio_iommu_has_sw_msi(struct
> list_head *group_resv_regions,
> return ret;
> }
>
> -static int vfio_mdev_attach_domain(struct device *dev, void *data)
> -{
> - struct mdev_device *mdev = to_mdev_device(dev);
> - struct iommu_domain *domain = data;
> - struct device *iommu_device;
> -
> - iommu_device = mdev_get_iommu_device(mdev);
> - if (iommu_device) {
> - if (iommu_dev_feature_enabled(iommu_device,
> IOMMU_DEV_FEAT_AUX))
> - return iommu_aux_attach_device(domain,
> iommu_device);
> - else
> - return iommu_attach_device(domain,
> iommu_device);
> - }
> -
> - return -EINVAL;
> -}
> -
> -static int vfio_mdev_detach_domain(struct device *dev, void *data)
> -{
> - struct mdev_device *mdev = to_mdev_device(dev);
> - struct iommu_domain *domain = data;
> - struct device *iommu_device;
> -
> - iommu_device = mdev_get_iommu_device(mdev);
> - if (iommu_device) {
> - if (iommu_dev_feature_enabled(iommu_device,
> IOMMU_DEV_FEAT_AUX))
> - iommu_aux_detach_device(domain, iommu_device);
> - else
> - iommu_detach_device(domain, iommu_device);
> - }
> -
> - return 0;
> -}
> -
> -static int vfio_iommu_attach_group(struct vfio_domain *domain,
> - struct vfio_iommu_group *group)
> -{
> - if (group->mdev_group)
> - return iommu_group_for_each_dev(group->iommu_group,
> - domain->domain,
> - vfio_mdev_attach_domain);
> - else
> - return iommu_attach_group(domain->domain, group-
> >iommu_group);
> -}
> -
> -static void vfio_iommu_detach_group(struct vfio_domain *domain,
> - struct vfio_iommu_group *group)
> -{
> - if (group->mdev_group)
> - iommu_group_for_each_dev(group->iommu_group,
> domain->domain,
> - vfio_mdev_detach_domain);
> - else
> - iommu_detach_group(domain->domain, group-
> >iommu_group);
> -}
> -
> static bool vfio_bus_is_mdev(struct bus_type *bus)
> {
> struct bus_type *mdev_bus;
> @@ -2004,20 +1948,6 @@ static bool vfio_bus_is_mdev(struct bus_type
> *bus)
> return ret;
> }
>
> -static int vfio_mdev_iommu_device(struct device *dev, void *data)
> -{
> - struct mdev_device *mdev = to_mdev_device(dev);
> - struct device **old = data, *new;
> -
> - new = mdev_get_iommu_device(mdev);
> - if (!new || (*old && *old != new))
> - return -EINVAL;
> -
> - *old = new;
> -
> - return 0;
> -}
> -
> /*
> * This is a helper function to insert an address range to iova list.
> * The list is initially created with a single entry corresponding to
> @@ -2278,38 +2208,25 @@ static int vfio_iommu_type1_attach_group(void
> *iommu_data,
> goto out_free;
>
> if (vfio_bus_is_mdev(bus)) {
> - struct device *iommu_device = NULL;
> -
> - group->mdev_group = true;
> -
> - /* Determine the isolation type */
> - ret = iommu_group_for_each_dev(iommu_group,
> &iommu_device,
> - vfio_mdev_iommu_device);
> - if (ret || !iommu_device) {
> - if (!iommu->external_domain) {
> - INIT_LIST_HEAD(&domain->group_list);
> - iommu->external_domain = domain;
> - vfio_update_pgsize_bitmap(iommu);
> - } else {
> - kfree(domain);
> - }
> -
> - list_add(&group->next,
> - &iommu->external_domain->group_list);
> - /*
> - * Non-iommu backed group cannot dirty memory
> directly,
> - * it can only use interfaces that provide dirty
> - * tracking.
> - * The iommu scope can only be promoted with the
> - * addition of a dirty tracking group.
> - */
> - group->pinned_page_dirty_scope = true;
> - mutex_unlock(&iommu->lock);
> -
> - return 0;
> + if (!iommu->external_domain) {
> + INIT_LIST_HEAD(&domain->group_list);
> + iommu->external_domain = domain;
> + vfio_update_pgsize_bitmap(iommu);
> + } else {
> + kfree(domain);
> }
>
> - bus = iommu_device->bus;
> + list_add(&group->next, &iommu->external_domain-
> >group_list);
> + /*
> + * Non-iommu backed group cannot dirty memory directly, it
> can
> + * only use interfaces that provide dirty tracking.
> + * The iommu scope can only be promoted with the addition
> of a
> + * dirty tracking group.
> + */
> + group->pinned_page_dirty_scope = true;
> + mutex_unlock(&iommu->lock);
> +
> + return 0;
> }
>
> domain->domain = iommu_domain_alloc(bus);
> @@ -2324,7 +2241,7 @@ static int vfio_iommu_type1_attach_group(void
> *iommu_data,
> goto out_domain;
> }
>
> - ret = vfio_iommu_attach_group(domain, group);
> + ret = iommu_attach_group(domain->domain, group->iommu_group);
> if (ret)
> goto out_domain;
>
> @@ -2391,15 +2308,17 @@ static int vfio_iommu_type1_attach_group(void
> *iommu_data,
> list_for_each_entry(d, &iommu->domain_list, next) {
> if (d->domain->ops == domain->domain->ops &&
> d->prot == domain->prot) {
> - vfio_iommu_detach_group(domain, group);
> - if (!vfio_iommu_attach_group(d, group)) {
> + iommu_detach_group(domain->domain, group-
> >iommu_group);
> + if (!iommu_attach_group(d->domain,
> + group->iommu_group)) {
> list_add(&group->next, &d->group_list);
> iommu_domain_free(domain->domain);
> kfree(domain);
> goto done;
> }
>
> - ret = vfio_iommu_attach_group(domain, group);
> + ret = iommu_attach_group(domain->domain,
> + group->iommu_group);
> if (ret)
> goto out_domain;
> }
> @@ -2436,7 +2355,7 @@ static int vfio_iommu_type1_attach_group(void
> *iommu_data,
> return 0;
>
> out_detach:
> - vfio_iommu_detach_group(domain, group);
> + iommu_detach_group(domain->domain, group->iommu_group);
> out_domain:
> iommu_domain_free(domain->domain);
> vfio_iommu_iova_free(&iova_copy);
> @@ -2601,7 +2520,7 @@ static void vfio_iommu_type1_detach_group(void
> *iommu_data,
> if (!group)
> continue;
>
> - vfio_iommu_detach_group(domain, group);
> + iommu_detach_group(domain->domain, group-
> >iommu_group);
> update_dirty_scope = !group->pinned_page_dirty_scope;
> list_del(&group->next);
> kfree(group);
> @@ -2689,7 +2608,7 @@ static void vfio_release_domain(struct
> vfio_domain *domain, bool external)
> list_for_each_entry_safe(group, group_tmp,
> &domain->group_list, next) {
> if (!external)
> - vfio_iommu_detach_group(domain, group);
> + iommu_detach_group(domain->domain, group-
> >iommu_group);
> list_del(&group->next);
> kfree(group);
> }
> diff --git a/include/linux/mdev.h b/include/linux/mdev.h
> index 68427e8fadebd6..15d03f6532d073 100644
> --- a/include/linux/mdev.h
> +++ b/include/linux/mdev.h
> @@ -18,7 +18,6 @@ struct mdev_device {
> void *driver_data;
> struct list_head next;
> struct mdev_type *type;
> - struct device *iommu_device;
> bool active;
> };
>
> @@ -27,25 +26,6 @@ static inline struct mdev_device
> *to_mdev_device(struct device *dev)
> return container_of(dev, struct mdev_device, dev);
> }
>
> -/*
> - * Called by the parent device driver to set the device which represents
> - * this mdev in iommu protection scope. By default, the iommu device is
> - * NULL, that indicates using vendor defined isolation.
> - *
> - * @dev: the mediated device that iommu will isolate.
> - * @iommu_device: a pci device which represents the iommu for @dev.
> - */
> -static inline void mdev_set_iommu_device(struct mdev_device *mdev,
> - struct device *iommu_device)
> -{
> - mdev->iommu_device = iommu_device;
> -}
> -
> -static inline struct device *mdev_get_iommu_device(struct mdev_device
> *mdev)
> -{
> - return mdev->iommu_device;
> -}
> -
> unsigned int mdev_get_type_group_id(struct mdev_device *mdev);
> unsigned int mtype_get_type_group_id(struct mdev_type *mtype);
> struct device *mtype_get_parent_dev(struct mdev_type *mtype);
> --
> 2.30.2
