Re: [PATCH v8 9/9] vfio/type1: Handle different mdev isolation type

From: Alex Williamson
Date: Tue Mar 26 2019 - 13:42:43 EST


On Mon, 25 Mar 2019 09:30:36 +0800
Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> wrote:

> This adds the support to determine the isolation type
> of a mediated device group by checking whether it has
> an iommu device. If an iommu device exists, an iommu
> domain will be allocated and then attached to the iommu
> device. Otherwise, keep the same behavior as it is.
>
> Cc: Ashok Raj <ashok.raj@xxxxxxxxx>
> Cc: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
> Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
> Signed-off-by: Sanjay Kumar <sanjay.k.kumar@xxxxxxxxx>
> Signed-off-by: Liu Yi L <yi.l.liu@xxxxxxxxx>
> Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> Reviewed-by: Jean-Philippe Brucker <jean-philippe.brucker@xxxxxxx>
> ---
> drivers/vfio/vfio_iommu_type1.c | 55 +++++++++++++++++++++++++--------
> 1 file changed, 42 insertions(+), 13 deletions(-)


Acked-by: Alex Williamson <alex.williamson@xxxxxxxxxx>


> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index ccc4165474aa..b91cafcd5181 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -559,7 +559,7 @@ static int vfio_iommu_type1_pin_pages(void *iommu_data,
> mutex_lock(&iommu->lock);
>
> /* Fail if notifier list is empty */
> - if ((!iommu->external_domain) || (!iommu->notifier.head)) {
> + if (!iommu->notifier.head) {
> ret = -EINVAL;
> goto pin_done;
> }
> @@ -641,11 +641,6 @@ static int vfio_iommu_type1_unpin_pages(void *iommu_data,
>
> mutex_lock(&iommu->lock);
>
> - if (!iommu->external_domain) {
> - mutex_unlock(&iommu->lock);
> - return -EINVAL;
> - }
> -
> do_accounting = !IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu);
> for (i = 0; i < npage; i++) {
> struct vfio_dma *dma;
> @@ -1368,13 +1363,40 @@ static void vfio_iommu_detach_group(struct vfio_domain *domain,
> iommu_detach_group(domain->domain, group->iommu_group);
> }
>
> +static bool vfio_bus_is_mdev(struct bus_type *bus)
> +{
> + struct bus_type *mdev_bus;
> + bool ret = false;
> +
> + mdev_bus = symbol_get(mdev_bus_type);
> + if (mdev_bus) {
> + ret = (bus == mdev_bus);
> + symbol_put(mdev_bus_type);
> + }
> +
> + return ret;
> +}
> +
> +static int vfio_mdev_iommu_device(struct device *dev, void *data)
> +{
> + struct device **old = data, *new;
> +
> + new = vfio_mdev_get_iommu_device(dev);
> + if (!new || (*old && *old != new))
> + return -EINVAL;
> +
> + *old = new;
> +
> + return 0;
> +}
> +
> 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;
> struct vfio_domain *domain, *d;
> - struct bus_type *bus = NULL, *mdev_bus;
> + struct bus_type *bus = NULL;
> int ret;
> bool resv_msi, msi_remap;
> phys_addr_t resv_msi_base;
> @@ -1409,23 +1431,30 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
> if (ret)
> goto out_free;
>
> - mdev_bus = symbol_get(mdev_bus_type);
> + if (vfio_bus_is_mdev(bus)) {
> + struct device *iommu_device = NULL;
>
> - if (mdev_bus) {
> - if ((bus == mdev_bus) && !iommu_present(bus)) {
> - symbol_put(mdev_bus_type);
> + group->mdev_group = true;
> +
> + /* Determine the isolation type */
> + ret = iommu_group_for_each_dev(iommu_group, &iommu_device,
> + vfio_mdev_iommu_device);
> + if (ret || !iommu_device) {
> if (!iommu->external_domain) {
> INIT_LIST_HEAD(&domain->group_list);
> iommu->external_domain = domain;
> - } else
> + } else {
> kfree(domain);
> + }
>
> list_add(&group->next,
> &iommu->external_domain->group_list);
> mutex_unlock(&iommu->lock);
> +
> return 0;
> }
> - symbol_put(mdev_bus_type);
> +
> + bus = iommu_device->bus;
> }
>
> domain->domain = iommu_domain_alloc(bus);