> From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> Sent: Friday, October 30, 2020 12:58 PM
>
> With the IOMMU driver registering iommu_ops for the mdev_bus, the
> IOMMU
> operations on an mdev could be done in the same way as any normal device
> (for example, PCI/PCIe). There's no need to distinguish an mdev from
> others for iommu operations. Remove the unnecessary code.
This is really a nice cleanup as the output of this change! :)
Thanks
Kevin
>
> Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> ---
> drivers/vfio/mdev/mdev_core.c | 18 -----
> drivers/vfio/mdev/mdev_driver.c | 6 ++
> drivers/vfio/mdev/mdev_private.h | 1 -
> drivers/vfio/vfio_iommu_type1.c | 128 +++----------------------------
> include/linux/mdev.h | 14 ----
> 5 files changed, 18 insertions(+), 149 deletions(-)
>
> diff --git a/drivers/vfio/mdev/mdev_core.c
> b/drivers/vfio/mdev/mdev_core.c
> index 6b9ab71f89e7..f4fd5f237c49 100644
> --- a/drivers/vfio/mdev/mdev_core.c
> +++ b/drivers/vfio/mdev/mdev_core.c
> @@ -386,24 +386,6 @@ int mdev_device_remove(struct device *dev)
> return 0;
> }
>
> -int mdev_set_iommu_device(struct device *dev, struct device
> *iommu_device)
> -{
> - struct mdev_device *mdev = to_mdev_device(dev);
> -
> - mdev->iommu_device = iommu_device;
> -
> - return 0;
> -}
> -EXPORT_SYMBOL(mdev_set_iommu_device);
> -
> -struct device *mdev_get_iommu_device(struct device *dev)
> -{
> - struct mdev_device *mdev = to_mdev_device(dev);
> -
> - return mdev->iommu_device;
> -}
> -EXPORT_SYMBOL(mdev_get_iommu_device);
> -
> static int __init mdev_init(void)
> {
> return mdev_bus_register();
> diff --git a/drivers/vfio/mdev/mdev_driver.c
> b/drivers/vfio/mdev/mdev_driver.c
> index 0d3223aee20b..487402f16355 100644
> --- a/drivers/vfio/mdev/mdev_driver.c
> +++ b/drivers/vfio/mdev/mdev_driver.c
> @@ -18,6 +18,9 @@ static int mdev_attach_iommu(struct mdev_device
> *mdev)
> int ret;
> struct iommu_group *group;
>
> + if (iommu_present(&mdev_bus_type))
> + return 0;
> +
> group = iommu_group_alloc();
> if (IS_ERR(group))
> return PTR_ERR(group);
> @@ -33,6 +36,9 @@ static int mdev_attach_iommu(struct mdev_device
> *mdev)
>
> static void mdev_detach_iommu(struct mdev_device *mdev)
> {
> + if (iommu_present(&mdev_bus_type))
> + return;
> +
> iommu_group_remove_device(&mdev->dev);
> dev_info(&mdev->dev, "MDEV: detaching iommu\n");
> }
> diff --git a/drivers/vfio/mdev/mdev_private.h
> b/drivers/vfio/mdev/mdev_private.h
> index 7d922950caaf..efe0aefdb52f 100644
> --- a/drivers/vfio/mdev/mdev_private.h
> +++ b/drivers/vfio/mdev/mdev_private.h
> @@ -31,7 +31,6 @@ struct mdev_device {
> void *driver_data;
> struct list_head next;
> struct kobject *type_kobj;
> - struct device *iommu_device;
> bool active;
> };
>
> diff --git a/drivers/vfio/vfio_iommu_type1.c
> b/drivers/vfio/vfio_iommu_type1.c
> index bb2684cc245e..e231b7070ca5 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -100,7 +100,6 @@ struct vfio_dma {
> struct vfio_group {
> struct iommu_group *iommu_group;
> struct list_head next;
> - bool mdev_group; /* An mdev group */
> bool pinned_page_dirty_scope;
> };
>
> @@ -1675,102 +1674,6 @@ static bool vfio_iommu_has_sw_msi(struct
> list_head *group_resv_regions,
> return ret;
> }
>
> -static struct device *vfio_mdev_get_iommu_device(struct device *dev)
> -{
> - struct device *(*fn)(struct device *dev);
> - struct device *iommu_device;
> -
> - fn = symbol_get(mdev_get_iommu_device);
> - if (fn) {
> - iommu_device = fn(dev);
> - symbol_put(mdev_get_iommu_device);
> -
> - return iommu_device;
> - }
> -
> - return NULL;
> -}
> -
> -static int vfio_mdev_attach_domain(struct device *dev, void *data)
> -{
> - struct iommu_domain *domain = data;
> - struct device *iommu_device;
> -
> - iommu_device = vfio_mdev_get_iommu_device(dev);
> - 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 iommu_domain *domain = data;
> - struct device *iommu_device;
> -
> - iommu_device = vfio_mdev_get_iommu_device(dev);
> - 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_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_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;
> - bool ret = false;
> -
> - mdev_bus = symbol_get(mdev_bus_type);
> - if (mdev_bus) {
> - ret = (bus == mdev_bus);
> - symbol_put(mdev_bus_type);
> - }
> -
> - return ret;
> -}
> -
> -static int vfio_mdev_iommu_device(struct device *dev, void *data)
> -{
> - struct device **old = data, *new;
> -
> - new = vfio_mdev_get_iommu_device(dev);
> - 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
> @@ -1999,7 +1902,7 @@ static int vfio_iommu_type1_attach_group(void
> *iommu_data,
> struct vfio_iommu *iommu = iommu_data;
> struct vfio_group *group;
> struct vfio_domain *domain, *d;
> - struct bus_type *bus = NULL;
> + struct bus_type *bus = NULL, *mdev_bus;
> int ret;
> bool resv_msi, msi_remap;
> phys_addr_t resv_msi_base = 0;
> @@ -2037,15 +1940,10 @@ static int vfio_iommu_type1_attach_group(void
> *iommu_data,
> if (ret)
> 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) {
> + mdev_bus = symbol_get(mdev_bus_type);
> + if (mdev_bus) {
> + if (bus == mdev_bus && !iommu_present(bus)) {
> + symbol_put(mdev_bus_type);
> if (!iommu->external_domain) {
> INIT_LIST_HEAD(&domain->group_list);
> iommu->external_domain = domain;
> @@ -2070,8 +1968,6 @@ static int vfio_iommu_type1_attach_group(void
> *iommu_data,
>
> return 0;
> }
> -
> - bus = iommu_device->bus;
> }
>
> domain->domain = iommu_domain_alloc(bus);
> @@ -2089,7 +1985,7 @@ 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, iommu_group);
> if (ret)
> goto out_domain;
>
> @@ -2157,15 +2053,15 @@ 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,
> iommu_group);
> + if (!iommu_attach_group(d->domain, 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,
> iommu_group);
> if (ret)
> goto out_domain;
> }
> @@ -2202,7 +2098,7 @@ 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, iommu_group);
> out_domain:
> iommu_domain_free(domain->domain);
> vfio_iommu_iova_free(&iova_copy);
> @@ -2385,7 +2281,7 @@ static void vfio_iommu_type1_detach_group(void
> *iommu_data,
> if (!group)
> continue;
>
> - vfio_iommu_detach_group(domain, group);
> + iommu_detach_group(domain->domain, iommu_group);
> update_dirty_scope = !group->pinned_page_dirty_scope;
> list_del(&group->next);
> kfree(group);
> @@ -2466,7 +2362,7 @@ 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 0ce30ca78db0..f7aee86bd2b0 100644
> --- a/include/linux/mdev.h
> +++ b/include/linux/mdev.h
> @@ -12,20 +12,6 @@
>
> struct mdev_device;
>
> -/*
> - * 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.
> - *
> - * Return 0 for success, otherwise negative error value.
> - */
> -int mdev_set_iommu_device(struct device *dev, struct device
> *iommu_device);
> -
> -struct device *mdev_get_iommu_device(struct device *dev);
> -
> /**
> * struct mdev_parent_ops - Structure to be registered for each parent
> device to
> * register the device to mdev module.
> --
> 2.25.1
