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

[Tian, Kevin]

> From: Nicolin Chen 
> 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  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 

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

[Nicolin Chen]

On Sun, Oct 27, 2024 at 11:02:31PM +0800, Zhangfei Gao wrote:
> On Sat, 26 Oct 2024 at 07:51, Nicolin Chen  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

[Zhangfei Gao]

On Sat, 26 Oct 2024 at 07:51, Nicolin Chen  wrote:
>
> This avoids a bigger trouble of exposing struct iommufd_device and struct
> iommufd_vdevice in the public header.
>
> Signed-off-by: Nicolin Chen 
> ---
>  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