Introduce a new ioctl to allocate a vDEVICE object. Since a vDEVICE object
is a connection of an iommufd_iommufd object and an iommufd_viommu object,
require both as the ioctl inputs and take refcounts in the ioctl handler.
Add to the vIOMMU object a "vdevs" xarray, indexed by a per-vIOMMU virtual
device ID, which can be:
- Virtual StreamID on a nested ARM SMMUv3, an index to a Stream Table
- Virtual DeviceID on a nested AMD IOMMU, an index to a Device Table
- Virtual ID on a nested Intel VT-D IOMMU, an index to a Context Table
Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
---
drivers/iommu/iommufd/iommufd_private.h | 11 +++
include/linux/iommufd.h | 2 +
include/uapi/linux/iommufd.h | 26 +++++++
drivers/iommu/iommufd/main.c | 6 ++
drivers/iommu/iommufd/viommu.c | 91 +++++++++++++++++++++++++
5 files changed, 136 insertions(+)
diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index 0c56a467e440..e160edb22b67 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -409,6 +409,7 @@ struct iommufd_device {
struct iommufd_object obj;
struct iommufd_ctx *ictx;
struct iommufd_group *igroup;
+ struct iommufd_vdevice *vdev;
struct list_head group_item;
/* always the physical device */
struct device *dev;
@@ -523,8 +524,18 @@ static inline int iommufd_hwpt_replace_device(struct iommufd_device *idev,
return iommu_group_replace_domain(idev->igroup->group, hwpt->domain);
}
+static inline struct iommufd_viommu *
+iommufd_get_viommu(struct iommufd_ucmd *ucmd, u32 id)
+{
+ return container_of(iommufd_get_object(ucmd->ictx, id,
+ IOMMUFD_OBJ_VIOMMU),
+ struct iommufd_viommu, obj);
+}
+
int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd);
void iommufd_viommu_destroy(struct iommufd_object *obj);
+int iommufd_vdevice_alloc_ioctl(struct iommufd_ucmd *ucmd);
+void iommufd_vdevice_destroy(struct iommufd_object *obj);
#ifdef CONFIG_IOMMUFD_TEST
int iommufd_test(struct iommufd_ucmd *ucmd);
diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h
index 510fc961a9ad..5a630952150d 100644
--- a/include/linux/iommufd.h
+++ b/include/linux/iommufd.h
@@ -72,6 +72,8 @@ struct iommufd_viommu {
const struct iommufd_viommu_ops *ops;
+ struct xarray vdevs;
+
unsigned int type;
};
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 6ee841a8c79b..3039519d71b7 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -52,6 +52,7 @@ enum {
IOMMUFD_CMD_HWPT_INVALIDATE = 0x8d,
IOMMUFD_CMD_FAULT_QUEUE_ALLOC = 0x8e,
IOMMUFD_CMD_VIOMMU_ALLOC = 0x8f,
+ IOMMUFD_CMD_VDEVICE_ALLOC = 0x90,
};
/**
@@ -894,4 +895,29 @@ struct iommu_viommu_alloc {
__u32 out_viommu_id;
};
#define IOMMU_VIOMMU_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_VIOMMU_ALLOC)
+
+/**
+ * struct iommu_vdevice_alloc - ioctl(IOMMU_VDEVICE_ALLOC)
+ * @size: sizeof(struct iommu_vdevice_alloc)
+ * @viommu_id: vIOMMU ID to associate with the virtual device
+ * @dev_id: The pyhsical device to allocate a virtual instance on the vIOMMU
+ * @__reserved: Must be 0
+ * @virt_id: Virtual device ID per vIOMMU, e.g. vSID of ARM SMMUv3, vDeviceID
+ * of AMD IOMMU, and vID of a nested Intel VT-d to a Context Table.
+ * @out_vdevice_id: Output virtual instance ID for the allocated object
+ * @__reserved2: Must be 0
+ *
+ * Allocate a virtual device instance (for a physical device) against a vIOMMU.
+ * This instance holds the device's information (related to its vIOMMU) in a VM.
+ */
+struct iommu_vdevice_alloc {
+ __u32 size;
+ __u32 viommu_id;
+ __u32 dev_id;
+ __u32 __reserved;
+ __aligned_u64 virt_id;
+ __u32 out_vdevice_id;
+ __u32 __reserved2;
+};
+#define IOMMU_VDEVICE_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_VDEVICE_ALLOC)
#endif
diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c
index cbd0a80b2d67..9a8c3cbecc11 100644
--- a/drivers/iommu/iommufd/main.c
+++ b/drivers/iommu/iommufd/main.c
@@ -302,6 +302,7 @@ union ucmd_buffer {
struct iommu_option option;
struct iommu_vfio_ioas vfio_ioas;
struct iommu_viommu_alloc viommu;
+ struct iommu_vdevice_alloc vdev;
#ifdef CONFIG_IOMMUFD_TEST
struct iommu_test_cmd test;
#endif
@@ -355,6 +356,8 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = {
__reserved),
IOCTL_OP(IOMMU_VIOMMU_ALLOC, iommufd_viommu_alloc_ioctl,
struct iommu_viommu_alloc, out_viommu_id),
+ IOCTL_OP(IOMMU_VDEVICE_ALLOC, iommufd_vdevice_alloc_ioctl,
+ struct iommu_vdevice_alloc, __reserved2),
#ifdef CONFIG_IOMMUFD_TEST
IOCTL_OP(IOMMU_TEST_CMD, iommufd_test, struct iommu_test_cmd, last),
#endif
@@ -493,6 +496,9 @@ static const struct iommufd_object_ops iommufd_object_ops[] = {
[IOMMUFD_OBJ_VIOMMU] = {
.destroy = iommufd_viommu_destroy,
},
+ [IOMMUFD_OBJ_VDEVICE] = {
+ .destroy = iommufd_vdevice_destroy,
+ },
#ifdef CONFIG_IOMMUFD_TEST
[IOMMUFD_OBJ_SELFTEST] = {
.destroy = iommufd_selftest_destroy,
diff --git a/drivers/iommu/iommufd/viommu.c b/drivers/iommu/iommufd/viommu.c
index f512dfb535fd..eb78c928c60f 100644
--- a/drivers/iommu/iommufd/viommu.c
+++ b/drivers/iommu/iommufd/viommu.c
@@ -9,6 +9,8 @@ void iommufd_viommu_destroy(struct iommufd_object *obj)
struct iommufd_viommu *viommu =
container_of(obj, struct iommufd_viommu, obj);
+ xa_destroy(&viommu->vdevs);
+
if (viommu->ops && viommu->ops->free)
viommu->ops->free(viommu);
refcount_dec(&viommu->hwpt->common.obj.users);
@@ -72,6 +74,8 @@ int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd)
*/
viommu->iommu_dev = idev->dev->iommu->iommu_dev;
+ xa_init(&viommu->vdevs);
+
refcount_inc(&viommu->hwpt->common.obj.users);
cmd->out_viommu_id = viommu->obj.id;
@@ -89,3 +93,90 @@ int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd)
iommufd_put_object(ucmd->ictx, &idev->obj);
return rc;
}
+
+void iommufd_vdevice_destroy(struct iommufd_object *obj)
+{
+ struct iommufd_vdevice *old, *vdev =
+ container_of(obj, struct iommufd_vdevice, obj);
+ struct iommufd_viommu *viommu = vdev->viommu;
+ struct iommufd_device *idev = vdev->idev;
+
+ if (viommu->ops && viommu->ops->vdevice_free)
+ viommu->ops->vdevice_free(vdev);
+
+ old = xa_cmpxchg(&viommu->vdevs, vdev->id, vdev, NULL, GFP_KERNEL);
+ if (old)
+ WARN_ON(old != vdev);
+
+ refcount_dec(&viommu->obj.users);
+ refcount_dec(&idev->obj.users);
+ idev->vdev = NULL;
+}
+
+int iommufd_vdevice_alloc_ioctl(struct iommufd_ucmd *ucmd)
+{
+ struct iommu_vdevice_alloc *cmd = ucmd->cmd;
+ struct iommufd_vdevice *vdev, *curr;
+ struct iommufd_viommu *viommu;
+ struct iommufd_device *idev;
+ u64 virt_id = cmd->virt_id;
+ int rc = 0;
+
+ if (virt_id > ULONG_MAX)
+ return -EINVAL;
+
+ viommu = iommufd_get_viommu(ucmd, cmd->viommu_id);
+ if (IS_ERR(viommu))
+ return PTR_ERR(viommu);
+
+ idev = iommufd_get_device(ucmd, cmd->dev_id);
+ if (IS_ERR(idev)) {
+ rc = PTR_ERR(idev);
+ goto out_put_viommu;
+ }
+
+ mutex_lock(&idev->igroup->lock);
+ if (idev->vdev) {
+ rc = -EEXIST;
+ goto out_unlock_igroup;
+ }
+
+ if (viommu->ops && viommu->ops->vdevice_alloc)
+ vdev = viommu->ops->vdevice_alloc(viommu, idev->dev, virt_id);
+ else
+ vdev = __iommufd_vdevice_alloc(ucmd->ictx, sizeof(*vdev));
+ if (IS_ERR(vdev)) {
+ rc = PTR_ERR(vdev);
+ goto out_unlock_igroup;
+ }
+
+ vdev->idev = idev;
+ vdev->id = virt_id;
+ vdev->viommu = viommu;
+
+ idev->vdev = vdev;
+ refcount_inc(&idev->obj.users);
+ refcount_inc(&viommu->obj.users);
+
+ curr = xa_cmpxchg(&viommu->vdevs, virt_id, NULL, vdev, GFP_KERNEL);
+ if (curr) {
+ rc = xa_err(curr) ? : -EBUSY;
+ goto out_abort;
+ }
+
+ cmd->out_vdevice_id = vdev->obj.id;
+ rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
+ if (rc)
+ goto out_abort;
+ iommufd_object_finalize(ucmd->ictx, &vdev->obj);
+ goto out_unlock_igroup;
+
+out_abort:
+ iommufd_object_abort_and_destroy(ucmd->ictx, &vdev->obj);
+out_unlock_igroup:
+ mutex_unlock(&idev->igroup->lock);
+ iommufd_put_object(ucmd->ictx, &idev->obj);
+out_put_viommu:
+ iommufd_put_object(ucmd->ictx, &viommu->obj);
+ return rc;
+}
--
2.43.0
