Hi Jean, vfio can be compiled as module, however you use some functions which are not exported. comment inline: [...] > Add two new ioctl for VFIO containers. VFIO_IOMMU_BIND_PROCESS creates a > bond between a container and a process address space, identified by a > device-specific ID named PASID. This allows the device to target DMA > transactions at the process virtual addresses without a need for mapping > and unmapping buffers explicitly in the IOMMU. The process page tables are > shared with the IOMMU, and mechanisms such as PCI ATS/PRI are used to > handle faults. VFIO_IOMMU_UNBIND_PROCESS removes a bond created with > VFIO_IOMMU_BIND_PROCESS. > > Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@xxxxxxx> > --- [...] > +static struct mm_struct *vfio_iommu_get_mm_by_vpid(pid_t vpid) > +{ > + struct mm_struct *mm; > + struct task_struct *task; > + > + rcu_read_lock(); > + task = find_task_by_vpid(vpid); Maybe can use? task = pid_task(find_vpid(params.vpid), PIDTYPE_PID) > + if (task) > + get_task_struct(task); > + rcu_read_unlock(); > + if (!task) > + return ERR_PTR(-ESRCH); > + > + /* Ensure that current has RW access on the mm */ > + mm = mm_access(task, PTRACE_MODE_ATTACH_REALCREDS); You will try to export mm_access, I find Felix have tried to, but seems give up: https://patchwork.kernel.org/patch/9744281/ Thanks Yisheng -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html