Re: [Qemu-devel] [PATCH v9 04/12] vfio iommu: Add support for mediated devices

[Jike Song]

On 10/18/2016 05:22 AM, Kirti Wankhede wrote:
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index 2ba19424e4a1..5d67058a611d 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
[snip]
>  static int vfio_iommu_type1_attach_group(void *iommu_data,
>                                        struct iommu_group *iommu_group)
>  {
>       struct vfio_iommu *iommu = iommu_data;
> -     struct vfio_group *group, *g;
> +     struct vfio_group *group;
>       struct vfio_domain *domain, *d;
>       struct bus_type *bus = NULL;
>       int ret;
> @@ -746,10 +1136,14 @@ static int vfio_iommu_type1_attach_group(void 
> *iommu_data,
>       mutex_lock(&iommu->lock);
>  
>       list_for_each_entry(d, &iommu->domain_list, next) {
> -             list_for_each_entry(g, &d->group_list, next) {
> -                     if (g->iommu_group != iommu_group)
> -                             continue;
> +             if (find_iommu_group(d, iommu_group)) {
> +                     mutex_unlock(&iommu->lock);
> +                     return -EINVAL;
> +             }
> +     }
>  
> +     if (iommu->local_domain) {
> +             if (find_iommu_group(iommu->local_domain, iommu_group)) {
>                       mutex_unlock(&iommu->lock);
>                       return -EINVAL;
>               }
> @@ -769,6 +1163,30 @@ static int vfio_iommu_type1_attach_group(void 
> *iommu_data,
>       if (ret)
>               goto out_free;
>  
> +     if (IS_ENABLED(CONFIG_VFIO_MDEV) && !iommu_present(bus) &&
> +         (bus == &mdev_bus_type)) {

Hi Kirti,

By refering mdev_bus_type directly you are making vfio_iommu_type1.ko depends
on mdev.ko, but in Kconfig doesn't guarantee the dependency. For example,
if CONFIG_VFIO_IOMMU_TYPE1=y and CONFIG_VFIO_MDEV=m, the building will fail.


--
Thanks,
Jike