Hi, On 23/05/18 10:38, Xu Zaibo wrote: >> +static int vfio_iommu_bind_group(struct vfio_iommu *iommu, >> + struct vfio_group *group, >> + struct vfio_mm *vfio_mm) >> +{ >> + int ret; >> + bool enabled_sva = false; >> + struct vfio_iommu_sva_bind_data data = { >> + .vfio_mm = vfio_mm, >> + .iommu = iommu, >> + .count = 0, >> + }; >> + >> + if (!group->sva_enabled) { >> + ret = iommu_group_for_each_dev(group->iommu_group, NULL, >> + vfio_iommu_sva_init); > Do we need to do *sva_init here or do anything to avoid repeated > initiation? > while another process already did initiation at this device, I think > that current process will get an EEXIST. Right, sva_init() must be called once for any device that intends to use bind(). For the second process though, group->sva_enabled will be true so we won't call sva_init() again, only bind(). Thanks, Jean