A VMID is generated in an IOMMU driver, being called from this
->attach_group() callback. So call ->get_vmid() right after it
creates a new VMID, and call ->set_vmid() before it, to let it
reuse the same VMID.
Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
---
drivers/vfio/vfio.c | 12 ++++++++++++
include/linux/vfio.h | 2 ++
2 files changed, 14 insertions(+)
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index c17b25c127a2..8b7442deca93 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -1080,9 +1080,21 @@ static int __vfio_container_attach_groups(struct vfio_container *container,
int ret = -ENODEV;
list_for_each_entry(group, &container->group_list, container_next) {
+ if (driver->ops->set_vmid && container->vmid != VFIO_IOMMU_VMID_INVALID) {
+ ret = driver->ops->set_vmid(data, container->vmid);
+ if (ret)
+ goto unwind;
+ }
+
ret = driver->ops->attach_group(data, group->iommu_group);
if (ret)
goto unwind;
+
+ if (driver->ops->get_vmid && container->vmid == VFIO_IOMMU_VMID_INVALID) {
+ ret = driver->ops->get_vmid(data, &container->vmid);
+ if (ret)
+ goto unwind;
+ }
}
return ret;
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index b53a9557884a..b43e7cbef4ab 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -126,6 +126,8 @@ struct vfio_iommu_driver_ops {
struct iommu_group *group);
void (*notify)(void *iommu_data,
enum vfio_iommu_notify_type event);
+ int (*set_vmid)(void *iommu_data, u32 vmid);
+ int (*get_vmid)(void *iommu_data, u32 *vmid);
};
extern int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops);
--
2.17.1
