[PATCH v5 07/13] iommufd/viommu: Add iommufd_viommu_find_dev helper

Nicolin Chen posted 13 patches 1 month ago
There is a newer version of this series
[PATCH v5 07/13] iommufd/viommu: Add iommufd_viommu_find_dev helper
Posted by Nicolin Chen 1 month ago
This avoids a bigger trouble of exposing struct iommufd_device and struct
iommufd_vdevice in the public header.

Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
 include/linux/iommufd.h        |  8 ++++++++
 drivers/iommu/iommufd/driver.c | 13 +++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h
index 0287a6d00192..dc174d02132b 100644
--- a/include/linux/iommufd.h
+++ b/include/linux/iommufd.h
@@ -184,6 +184,8 @@ static inline int iommufd_vfio_compat_set_no_iommu(struct iommufd_ctx *ictx)
 struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
 					     size_t size,
 					     enum iommufd_object_type type);
+struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu,
+				       unsigned long vdev_id);
 #else /* !CONFIG_IOMMUFD_DRIVER */
 static inline struct iommufd_object *
 _iommufd_object_alloc(struct iommufd_ctx *ictx, size_t size,
@@ -191,6 +193,12 @@ _iommufd_object_alloc(struct iommufd_ctx *ictx, size_t size,
 {
 	return ERR_PTR(-EOPNOTSUPP);
 }
+
+static inline struct device *
+iommufd_viommu_find_dev(struct iommufd_viommu *viommu, unsigned long vdev_id)
+{
+	return NULL;
+}
 #endif /* CONFIG_IOMMUFD_DRIVER */
 
 /*
diff --git a/drivers/iommu/iommufd/driver.c b/drivers/iommu/iommufd/driver.c
index c0876d3f91c7..3604443f82a1 100644
--- a/drivers/iommu/iommufd/driver.c
+++ b/drivers/iommu/iommufd/driver.c
@@ -36,3 +36,16 @@ struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
 	return ERR_PTR(rc);
 }
 EXPORT_SYMBOL_NS_GPL(_iommufd_object_alloc, IOMMUFD);
+
+/* Caller should xa_lock(&viommu->vdevs) to protect the return value */
+struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu,
+				       unsigned long vdev_id)
+{
+	struct iommufd_vdevice *vdev;
+
+	lockdep_is_held(&viommu->vdevs.xa_lock);
+
+	vdev = xa_load(&viommu->vdevs, vdev_id);
+	return vdev ? vdev->idev->dev : NULL;
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_viommu_find_dev, IOMMUFD);
-- 
2.43.0
Re: [PATCH v5 07/13] iommufd/viommu: Add iommufd_viommu_find_dev helper
Posted by Zhangfei Gao 4 weeks ago
On Sat, 26 Oct 2024 at 07:51, Nicolin Chen <nicolinc@nvidia.com> wrote:
>
> This avoids a bigger trouble of exposing struct iommufd_device and struct
> iommufd_vdevice in the public header.
>
> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
> ---
>  include/linux/iommufd.h        |  8 ++++++++
>  drivers/iommu/iommufd/driver.c | 13 +++++++++++++
>  2 files changed, 21 insertions(+)
>
> diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h
> index 0287a6d00192..dc174d02132b 100644
> --- a/include/linux/iommufd.h
> +++ b/include/linux/iommufd.h
> @@ -184,6 +184,8 @@ static inline int iommufd_vfio_compat_set_no_iommu(struct iommufd_ctx *ictx)
>  struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
>                                              size_t size,
>                                              enum iommufd_object_type type);
> +struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu,
> +                                      unsigned long vdev_id);
>  #else /* !CONFIG_IOMMUFD_DRIVER */
>  static inline struct iommufd_object *
>  _iommufd_object_alloc(struct iommufd_ctx *ictx, size_t size,
> @@ -191,6 +193,12 @@ _iommufd_object_alloc(struct iommufd_ctx *ictx, size_t size,
>  {
>         return ERR_PTR(-EOPNOTSUPP);
>  }
> +
> +static inline struct device *
> +iommufd_viommu_find_dev(struct iommufd_viommu *viommu, unsigned long vdev_id)
> +{
> +       return NULL;
> +}
>  #endif /* CONFIG_IOMMUFD_DRIVER */
>
>  /*
> diff --git a/drivers/iommu/iommufd/driver.c b/drivers/iommu/iommufd/driver.c
> index c0876d3f91c7..3604443f82a1 100644
> --- a/drivers/iommu/iommufd/driver.c
> +++ b/drivers/iommu/iommufd/driver.c
> @@ -36,3 +36,16 @@ struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
>         return ERR_PTR(rc);
>  }
>  EXPORT_SYMBOL_NS_GPL(_iommufd_object_alloc, IOMMUFD);
> +
> +/* Caller should xa_lock(&viommu->vdevs) to protect the return value */
> +struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu,
> +                                      unsigned long vdev_id)
> +{
> +       struct iommufd_vdevice *vdev;
> +
> +       lockdep_is_held(&viommu->vdevs.xa_lock);
> +
> +       vdev = xa_load(&viommu->vdevs, vdev_id);
> +       return vdev ? vdev->idev->dev : NULL;
> +}

Got this error?

ld: Unexpected GOT/PLT entries detected!
ld: Unexpected run-time procedure linkages detected!
ld: drivers/iommu/iommufd/driver.o: in function `iommufd_viommu_find_dev':
linux/drivers/iommu/iommufd/driver.c:47: undefined reference to
`lockdep_is_held'
make[2]: *** [scripts/Makefile.vmlinux:34: vmlinux] Error 1
make[1]: *** [/home/linaro/iommufd/linux/Makefile:1166: vmlinux] Error 2
make: *** [Makefile:224: __sub-make] Error 2
Re: [PATCH v5 07/13] iommufd/viommu: Add iommufd_viommu_find_dev helper
Posted by Nicolin Chen 4 weeks ago
On Sun, Oct 27, 2024 at 11:02:31PM +0800, Zhangfei Gao wrote:
> On Sat, 26 Oct 2024 at 07:51, Nicolin Chen <nicolinc@nvidia.com> wrote:
> > +/* Caller should xa_lock(&viommu->vdevs) to protect the return value */
> > +struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu,
> > +                                      unsigned long vdev_id)
> > +{
> > +       struct iommufd_vdevice *vdev;
> > +
> > +       lockdep_is_held(&viommu->vdevs.xa_lock);
> > +
> > +       vdev = xa_load(&viommu->vdevs, vdev_id);
> > +       return vdev ? vdev->idev->dev : NULL;
> > +}
> 
> Got this error?
> 
> ld: Unexpected GOT/PLT entries detected!
> ld: Unexpected run-time procedure linkages detected!
> ld: drivers/iommu/iommufd/driver.o: in function `iommufd_viommu_find_dev':
> linux/drivers/iommu/iommufd/driver.c:47: undefined reference to
> `lockdep_is_held'
> make[2]: *** [scripts/Makefile.vmlinux:34: vmlinux] Error 1
> make[1]: *** [/home/linaro/iommufd/linux/Makefile:1166: vmlinux] Error 2
> make: *** [Makefile:224: __sub-make] Error 2

Should fix it with:
-	lockdep_is_held(&viommu->vdevs.xa_lock);
+	lockdep_assert_held(&viommu->vdevs.xa_lock);

Thanks
Nicolin
RE: [PATCH v5 07/13] iommufd/viommu: Add iommufd_viommu_find_dev helper
Posted by Tian, Kevin 3 weeks, 6 days ago
> From: Nicolin Chen <nicolinc@nvidia.com>
> Sent: Monday, October 28, 2024 6:49 AM
> 
> On Sun, Oct 27, 2024 at 11:02:31PM +0800, Zhangfei Gao wrote:
> > On Sat, 26 Oct 2024 at 07:51, Nicolin Chen <nicolinc@nvidia.com> wrote:
> > > +/* Caller should xa_lock(&viommu->vdevs) to protect the return value
> */
> > > +struct device *iommufd_viommu_find_dev(struct iommufd_viommu
> *viommu,
> > > +                                      unsigned long vdev_id)
> > > +{
> > > +       struct iommufd_vdevice *vdev;
> > > +
> > > +       lockdep_is_held(&viommu->vdevs.xa_lock);
> > > +
> > > +       vdev = xa_load(&viommu->vdevs, vdev_id);
> > > +       return vdev ? vdev->idev->dev : NULL;
> > > +}
> >
> > Got this error?
> >
> > ld: Unexpected GOT/PLT entries detected!
> > ld: Unexpected run-time procedure linkages detected!
> > ld: drivers/iommu/iommufd/driver.o: in function
> `iommufd_viommu_find_dev':
> > linux/drivers/iommu/iommufd/driver.c:47: undefined reference to
> > `lockdep_is_held'
> > make[2]: *** [scripts/Makefile.vmlinux:34: vmlinux] Error 1
> > make[1]: *** [/home/linaro/iommufd/linux/Makefile:1166: vmlinux] Error
> 2
> > make: *** [Makefile:224: __sub-make] Error 2
> 
> Should fix it with:
> -	lockdep_is_held(&viommu->vdevs.xa_lock);
> +	lockdep_assert_held(&viommu->vdevs.xa_lock);
> 

with that,

Reviewed-by: Kevin Tian <kevin.tian@intel.com>