[PATCH v2 2/3] iommufd/tsm: add vdevice TSM bind/unbind ioctl

Aneesh Kumar K.V (Arm)
2026-03-09T11:17:38Z

Introduce IOMMU_VDEVICE_TSM_OP to allow userspace to issue TSM bind/unbind
operations for an iommufd vdevice.

The new ioctl:
- looks up the vdevice object from vdevice_id
- resolves the associated KVM VM from the vIOMMU KVM file reference
- dispatches bind/unbind via tsm_bind()/tsm_unbind()

Also add common TSM helpers in tsm-core and wire vdevice teardown to unbind
the device from TSM state.

This provides iommufd plumbing to bind a TDI to a confidential guest through
the TSM layer.

Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Will Deacon <will@kernel.org>
Cc: Bjorn Helgaas <helgaas@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Alexey Kardashevskiy <aik@amd.com>
Cc: Samuel Ortiz <sameo@rivosinc.com>
Cc: Xu Yilun <yilun.xu@linux.intel.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Suzuki K Poulose <Suzuki.Poulose@arm.com>
Cc: Steven Price <steven.price@arm.com>
Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
---
drivers/iommu/iommufd/Makefile | 2 +
drivers/iommu/iommufd/iommufd_private.h | 8 +++
drivers/iommu/iommufd/main.c | 3 ++
drivers/iommu/iommufd/tsm.c | 67 +++++++++++++++++++++++++
drivers/iommu/iommufd/viommu.c | 3 ++
drivers/virt/coco/tsm-core.c | 19 +++++++
include/linux/tsm.h | 18 +++++++
include/uapi/linux/iommufd.h | 18 +++++++
8 files changed, 138 insertions(+)
create mode 100644 drivers/iommu/iommufd/tsm.c

diff --git a/drivers/iommu/iommufd/Makefile b/drivers/iommu/iommufd/Makefile
index 71d692c9a8f4..431089089ee9 100644
--- a/drivers/iommu/iommufd/Makefile
+++ b/drivers/iommu/iommufd/Makefile
@@ -10,6 +10,8 @@ iommufd-y := \
vfio_compat.o \
viommu.o

+iommufd-$(CONFIG_TSM) += tsm.o
+
iommufd-$(CONFIG_IOMMUFD_TEST) += selftest.o

obj-$(CONFIG_IOMMUFD) += iommufd.o
diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index 6ac1965199e9..aa1ceed924c2 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -697,6 +697,14 @@ void iommufd_vdevice_destroy(struct iommufd_object *obj);
void iommufd_vdevice_abort(struct iommufd_object *obj);
int iommufd_hw_queue_alloc_ioctl(struct iommufd_ucmd *ucmd);
void iommufd_hw_queue_destroy(struct iommufd_object *obj);
+#ifdef CONFIG_TSM
+int iommufd_vdevice_tsm_op_ioctl(struct iommufd_ucmd *ucmd);
+#else
+static inline int iommufd_vdevice_tsm_op_ioctl(struct iommufd_ucmd *ucmd)
+{
+ return -EOPNOTSUPP;
+}
+#endif

static inline struct iommufd_vdevice *
iommufd_get_vdevice(struct iommufd_ctx *ictx, u32 id)
diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c
index 8c6d43601afb..d73e6b391c6f 100644
--- a/drivers/iommu/iommufd/main.c
+++ b/drivers/iommu/iommufd/main.c
@@ -432,6 +432,7 @@ union ucmd_buffer {
struct iommu_veventq_alloc veventq;
struct iommu_vfio_ioas vfio_ioas;
struct iommu_viommu_alloc viommu;
+ struct iommu_vdevice_tsm_op tsm_op;
#ifdef CONFIG_IOMMUFD_TEST
struct iommu_test_cmd test;
#endif
@@ -493,6 +494,8 @@ 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_TSM_OP, iommufd_vdevice_tsm_op_ioctl,
+ struct iommu_vdevice_tsm_op, vdevice_id),
#ifdef CONFIG_IOMMUFD_TEST
IOCTL_OP(IOMMU_TEST_CMD, iommufd_test, struct iommu_test_cmd, last),
#endif
diff --git a/drivers/iommu/iommufd/tsm.c b/drivers/iommu/iommufd/tsm.c
new file mode 100644
index 000000000000..401469110752
--- /dev/null
+++ b/drivers/iommu/iommufd/tsm.c
@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2026 ARM Ltd.
+ */
+
+#include "iommufd_private.h"
+#include <linux/tsm.h>
+
+/**
+ * iommufd_vdevice_tsm_op_ioctl - Handle vdevice TSM operations
+ * @ucmd: user command data for IOMMU_VDEVICE_TSM_OP
+ *
+ * Currently only supports TSM bind/unbind operations
+ * Resolve @iommu_vdevice_tsm_op::vdevice_id to a vdevice and dispatch the
+ * requested bind/unbind operation through the TSM core.
+ *
+ * Return: 0 on success, or a negative error code on failure.
+ */
+int iommufd_vdevice_tsm_op_ioctl(struct iommufd_ucmd *ucmd)
+{
+ int rc;
+ struct kvm *kvm;
+ struct iommufd_vdevice *vdev;
+ struct iommu_vdevice_tsm_op *cmd = ucmd->cmd;
+
+ if (cmd->flags)
+ return -EOPNOTSUPP;
+
+ vdev = container_of(iommufd_get_object(ucmd->ictx, cmd->vdevice_id,
+ IOMMUFD_OBJ_VDEVICE),
+ struct iommufd_vdevice, obj);
+ if (IS_ERR(vdev))
+ return PTR_ERR(vdev);
+
+ if (!vdev->viommu->kvm_filp) {
+ rc = -ENODEV;
+ goto out_put_vdev;
+ }
+
+ kvm = vdev->viommu->kvm_filp->private_data;
+ if (!kvm) {
+ rc = -ENODEV;
+ goto out_put_vdev;
+ }
+
+ /* tsm layer will take care of parallel calls to tsm_bind/unbind */
+ switch (cmd->op) {
+ case IOMMU_VDEVICE_TSM_BIND:
+ rc = tsm_bind(vdev->idev->dev, kvm, vdev->virt_id);
+ break;
+ case IOMMU_VDEVICE_TSM_UNBIND:
+ rc = tsm_unbind(vdev->idev->dev);
+ break;
+ default:
+ rc = -EINVAL;
+ goto out_put_vdev;
+ }
+
+ if (rc)
+ goto out_put_vdev;
+
+ rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
+
+out_put_vdev:
+ iommufd_put_object(ucmd->ictx, &vdev->obj);
+ return rc;
+}
diff --git a/drivers/iommu/iommufd/viommu.c b/drivers/iommu/iommufd/viommu.c
index 08f8930c86da..8eb7a3441a61 100644
--- a/drivers/iommu/iommufd/viommu.c
+++ b/drivers/iommu/iommufd/viommu.c
@@ -3,6 +3,7 @@
*/
#include "iommufd_private.h"
#include <linux/cleanup.h>
+#include <linux/tsm.h>

#if IS_ENABLED(CONFIG_KVM)
#include <linux/kvm_host.h>
@@ -171,6 +172,8 @@ void iommufd_vdevice_abort(struct iommufd_object *obj)

lockdep_assert_held(&idev->igroup->lock);

+ tsm_unbind(idev->dev);
+
if (vdev->destroy)
vdev->destroy(vdev);
/* xa_cmpxchg is okay to fail if alloc failed xa_cmpxchg previously */
diff --git a/drivers/virt/coco/tsm-core.c b/drivers/virt/coco/tsm-core.c
index ae3617abd2ac..f0e35fc38776 100644
--- a/drivers/virt/coco/tsm-core.c
+++ b/drivers/virt/coco/tsm-core.c
@@ -240,6 +240,25 @@ void tsm_ide_stream_unregister(struct pci_ide *ide)
}
EXPORT_SYMBOL_GPL(tsm_ide_stream_unregister);

+int tsm_bind(struct device *dev, struct kvm *kvm, u64 tdi_id)
+{
+ if (!dev_is_pci(dev))
+ return -EINVAL;
+
+ return pci_tsm_bind(to_pci_dev(dev), kvm, tdi_id);
+}
+EXPORT_SYMBOL_GPL(tsm_bind);
+
+int tsm_unbind(struct device *dev)
+{
+ if (!dev_is_pci(dev))
+ return -EINVAL;
+
+ pci_tsm_unbind(to_pci_dev(dev));
+ return 0;
+}
+EXPORT_SYMBOL_GPL(tsm_unbind);
+
static void tsm_release(struct device *dev)
{
struct tsm_dev *tsm_dev = container_of(dev, typeof(*tsm_dev), dev);
diff --git a/include/linux/tsm.h b/include/linux/tsm.h
index 7f72a154b6b2..9f2a7868021a 100644
--- a/include/linux/tsm.h
+++ b/include/linux/tsm.h
@@ -124,6 +124,24 @@ struct tsm_dev *tsm_register(struct device *parent, struct pci_tsm_ops *ops);
void tsm_unregister(struct tsm_dev *tsm_dev);
struct tsm_dev *find_tsm_dev(int id);
struct pci_ide;
+struct kvm;
int tsm_ide_stream_register(struct pci_ide *ide);
void tsm_ide_stream_unregister(struct pci_ide *ide);
+#ifdef CONFIG_TSM
+int tsm_bind(struct device *dev, struct kvm *kvm, u64 tdi_id);
+int tsm_unbind(struct device *dev);
+
+#else
+
+static inline int tsm_bind(struct device *dev, struct kvm *kvm, u64 tdi_id)
+{
+ return -EINVAL;
+}
+
+static inline int tsm_unbind(struct device *dev)
+{
+ return 0;
+}
+#endif
+
#endif /* __TSM_H */
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index b862c3e57133..653402e7048a 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -57,6 +57,7 @@ enum {
IOMMUFD_CMD_IOAS_CHANGE_PROCESS = 0x92,
IOMMUFD_CMD_VEVENTQ_ALLOC = 0x93,
IOMMUFD_CMD_HW_QUEUE_ALLOC = 0x94,
+ IOMMUFD_CMD_VDEVICE_TSM_OP = 0x95,
};

/**
@@ -1174,6 +1175,23 @@ enum iommu_veventq_flag {
IOMMU_VEVENTQ_FLAG_LOST_EVENTS = (1U << 0),
};

+/**
+ * struct iommu_vdevice_tsm_op - ioctl(IOMMU_VDEVICE_TSM_OP)
+ * @size: sizeof(struct iommu_vdevice_tsm_op)
+ * @op: Either TSM_BIND or TSM_UNBIND
+ * @flags: Must be 0
+ * @vdevice_id: Object handle for the vDevice. Returned from IOMMU_VDEVICE_ALLOC
+ */
+struct iommu_vdevice_tsm_op {
+ __u32 size;
+ __u32 op;
+ __u32 flags;
+ __u32 vdevice_id;
+};
+#define IOMMU_VDEVICE_TSM_OP _IO(IOMMUFD_TYPE, IOMMUFD_CMD_VDEVICE_TSM_OP)
+#define IOMMU_VDEVICE_TSM_BIND 0x1
+#define IOMMU_VDEVICE_TSM_UNBIND 0x2
+
/**
* struct iommufd_vevent_header - Virtual Event Header for a vEVENTQ Status
* @flags: Combination of enum iommu_veventq_flag
--
2.43.0