[PATCH v6 5/5] vfio/type1: Use mdev bus iommu_ops for IOMMU callbacks

From: Lu Baolu
Date: Fri Oct 30 2020 - 01:05:35 EST


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.

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