[PATCH v11 21/23] vfio: Determine noiommu device in __vfio_register_dev()

Yi Liu
2023-05-13T13:30:02Z

This is to make the cdev path and group path consistent for the noiommu
devices registration. If vfio_noiommu is disabled, such registration
should fail. However, this check is vfio_device_set_group() which is part
of the vfio_group code. If the vfio_group code is compiled out, noiommu
devices would be registered even vfio_noiommu is disabled.

This adds vfio_device_set_noiommu() which can fail and calls it in the
device registration. For now, it never fails as long as
vfio_device_set_group() is successful. But when the vfio_group code is
compiled out, vfio_device_set_noiommu() would fail the noiommu devices
when vfio_noiommu is disabled.

As noiommu devices is checked and there are multiple places which needs
to test noiommu devices, this also adds a flag to mark noiommu devices.
Hence the callers of vfio_device_is_noiommu() can be converted to test
vfio_device->noiommu.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
drivers/vfio/device_cdev.c | 4 ++--
drivers/vfio/group.c | 2 +-
drivers/vfio/iommufd.c | 10 +++++-----
drivers/vfio/vfio.h | 7 ++++---
drivers/vfio/vfio_main.c | 6 +++++-
include/linux/vfio.h | 1 +
6 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/drivers/vfio/device_cdev.c b/drivers/vfio/device_cdev.c
index 3f14edb80a93..6d7f50ee535d 100644
--- a/drivers/vfio/device_cdev.c
+++ b/drivers/vfio/device_cdev.c
@@ -111,7 +111,7 @@ long vfio_device_ioctl_bind_iommufd(struct vfio_device_file *df,
if (df->group)
return -EINVAL;

- if (vfio_device_is_noiommu(device) && !capable(CAP_SYS_RAWIO))
+ if (device->noiommu && !capable(CAP_SYS_RAWIO))
return -EPERM;

ret = vfio_device_block_group(device);
@@ -157,7 +157,7 @@ long vfio_device_ioctl_bind_iommufd(struct vfio_device_file *df,
device->cdev_opened = true;
mutex_unlock(&device->dev_set->lock);

- if (vfio_device_is_noiommu(device))
+ if (device->noiommu)
dev_warn(device->dev, "noiommu device is bound to iommufd by user "
"(%s:%d)\n", current->comm, task_pid_nr(current));
return 0;
diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c
index 7aacbd9d08c9..bf4335bce892 100644
--- a/drivers/vfio/group.c
+++ b/drivers/vfio/group.c
@@ -192,7 +192,7 @@ static int vfio_device_group_open(struct vfio_device_file *df)
vfio_device_group_get_kvm_safe(device);

df->iommufd = device->group->iommufd;
- if (df->iommufd && vfio_device_is_noiommu(device) && device->open_count == 0) {
+ if (df->iommufd && device->noiommu && device->open_count == 0) {
ret = vfio_iommufd_compat_probe_noiommu(device,
df->iommufd);
if (ret)
diff --git a/drivers/vfio/iommufd.c b/drivers/vfio/iommufd.c
index 799ea322a7d4..dfe706f1e952 100644
--- a/drivers/vfio/iommufd.c
+++ b/drivers/vfio/iommufd.c
@@ -71,7 +71,7 @@ int vfio_iommufd_bind(struct vfio_device_file *df)

lockdep_assert_held(&vdev->dev_set->lock);

- if (vfio_device_is_noiommu(vdev))
+ if (vdev->noiommu)
return vfio_iommufd_noiommu_bind(vdev, ictx, &df->devid);

return vdev->ops->bind_iommufd(vdev, ictx, &df->devid);
@@ -86,7 +86,7 @@ int vfio_iommufd_compat_attach_ioas(struct vfio_device *vdev,
lockdep_assert_held(&vdev->dev_set->lock);

/* compat noiommu does not need to do ioas attach */
- if (vfio_device_is_noiommu(vdev))
+ if (vdev->noiommu)
return 0;

ret = iommufd_vfio_compat_ioas_get_id(ictx, &ioas_id);
@@ -103,7 +103,7 @@ void vfio_iommufd_unbind(struct vfio_device_file *df)

lockdep_assert_held(&vdev->dev_set->lock);

- if (vfio_device_is_noiommu(vdev)) {
+ if (vdev->noiommu) {
vfio_iommufd_noiommu_unbind(vdev);
return;
}
@@ -116,7 +116,7 @@ int vfio_iommufd_attach(struct vfio_device *vdev, u32 *pt_id)
{
lockdep_assert_held(&vdev->dev_set->lock);

- if (vfio_device_is_noiommu(vdev))
+ if (vdev->noiommu)
return 0;

return vdev->ops->attach_ioas(vdev, pt_id);
@@ -126,7 +126,7 @@ void vfio_iommufd_detach(struct vfio_device *vdev)
{
lockdep_assert_held(&vdev->dev_set->lock);

- if (!vfio_device_is_noiommu(vdev))
+ if (!vdev->noiommu)
vdev->ops->detach_ioas(vdev);
}

diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
index 50553f67600f..c8579d63b2b9 100644
--- a/drivers/vfio/vfio.h
+++ b/drivers/vfio/vfio.h
@@ -106,10 +106,11 @@ bool vfio_device_has_container(struct vfio_device *device);
int __init vfio_group_init(void);
void vfio_group_cleanup(void);

-static inline bool vfio_device_is_noiommu(struct vfio_device *vdev)
+static inline int vfio_device_set_noiommu(struct vfio_device *device)
{
- return IS_ENABLED(CONFIG_VFIO_NOIOMMU) &&
- vdev->group->type == VFIO_NO_IOMMU;
+ device->noiommu = IS_ENABLED(CONFIG_VFIO_NOIOMMU) &&
+ device->group->type == VFIO_NO_IOMMU;
+ return 0;
}

#if IS_ENABLED(CONFIG_VFIO_CONTAINER)
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index 8c3f26b4929b..8979f320d620 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -289,8 +289,12 @@ static int __vfio_register_dev(struct vfio_device *device,
if (ret)
return ret;

+ ret = vfio_device_set_noiommu(device);
+ if (ret)
+ goto err_out;
+
ret = dev_set_name(&device->device, "%svfio%d",
- vfio_device_is_noiommu(device) ? "noiommu-" : "", device->index);
+ device->noiommu ? "noiommu-" : "", device->index);
if (ret)
goto err_out;

diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index cf9d082a623c..fa13889e763f 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -68,6 +68,7 @@ struct vfio_device {
bool iommufd_attached;
#endif
bool cdev_opened:1;
+ bool noiommu:1;
};

/**
--
2.34.1