Add new kAPIs against iommufd_device to support TSM Bind/Unbind
commands issued by CoCo-VM. The TSM bind means VMM does all
preparations for private device assignement, lock down the device by
transiting it to TDISP CONFIG_LOCKED or RUN state (when in RUN state,
TSM could still block any accessing to/from device), so that the device
is ready for attestation by CoCo-VM.
The interfaces are added against IOMMUFD because IOMMUFD builds several
abstract objects applicable for private device assignment, e.g. viommu
for secure iommu & kvm, vdevice for vBDF. IOMMUFD links them up to
finish all configurations required by secure firmware. That also means
TSM Bind interface should be called after viommu & vdevice allocation.
Suggested-by: Jason Gunthorpe <j...@nvidia.com>
Originally-by: Alexey Kardashevskiy <a...@amd.com>
Signed-off-by: Xu Yilun <yilun...@linux.intel.com>
---
drivers/iommu/iommufd/device.c | 84 +++++++++++++++++++++++++
drivers/iommu/iommufd/iommufd_private.h | 6 ++
drivers/iommu/iommufd/viommu.c | 44 +++++++++++++
include/linux/iommufd.h | 3 +
4 files changed, 137 insertions(+)
diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index 37ef6bec2009..984780c66ab2 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -3,6 +3,7 @@
*/
#include <linux/iommu.h>
#include <linux/iommufd.h>
+#include <linux/pci.h>
#include <linux/pci-ats.h>
#include <linux/slab.h>
#include <uapi/linux/iommufd.h>
@@ -1561,3 +1562,86 @@ int iommufd_get_hw_info(struct iommufd_ucmd *ucmd)
iommufd_put_object(ucmd->ictx, &idev->obj);
return rc;
}
+
+/**
+ * iommufd_device_tsm_bind - Move a device to TSM Bind state
+ * @idev: device to attach
+ * @vdev_id: Input a IOMMUFD_OBJ_VDEVICE
+ *
+ * This configures for device Confidential Computing(CC), and moves the device
+ * to the TSM Bind state. Once this completes the device is locked down (TDISP
+ * CONFIG_LOCKED or RUN), waiting for guest's attestation.
+ *
+ * This function is undone by calling iommufd_device_tsm_unbind().
+ */
+int iommufd_device_tsm_bind(struct iommufd_device *idev, u32 vdevice_id)
+{
+ struct iommufd_vdevice *vdev;
+ int rc;
+
+ if (!dev_is_pci(idev->dev))
+ return -ENODEV;
+
+ vdev = container_of(iommufd_get_object(idev->ictx, vdevice_id,
IOMMUFD_OBJ_VDEVICE),
+ struct iommufd_vdevice, obj);
+ if (IS_ERR(vdev))
+ return PTR_ERR(vdev);
+
+ if (vdev->dev != idev->dev) {
+ rc = -EINVAL;
+ goto out_put_vdev;
+ }
+
+ mutex_lock(&idev->igroup->lock);
+ if (idev->vdev) {
+ rc = -EEXIST;
+ goto out_unlock;
+ }
+
+ rc = iommufd_vdevice_tsm_bind(vdev);
+ if (rc)
+ goto out_unlock;
+
+ idev->vdev = vdev;
+ refcount_inc(&vdev->obj.users);
+ mutex_unlock(&idev->igroup->lock);
+
+ /*
+ * Pairs with iommufd_device_tsm_unbind() - catches caller bugs
attempting
+ * to destroy a bound device.
+ */
+ refcount_inc(&idev->obj.users);
+ goto out_put_vdev;
+
+out_unlock:
+ mutex_unlock(&idev->igroup->lock);
+out_put_vdev:
+ iommufd_put_object(idev->ictx, &vdev->obj);
+ return rc;
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_device_tsm_bind, "IOMMUFD");
+
+/**
+ * iommufd_device_tsm_unbind - Move a device out of TSM bind state
+ * @idev: device to detach
+ *
+ * Undo iommufd_device_tsm_bind(). This removes all Confidential Computing
+ * configurations, Once this completes the device is unlocked (TDISP
+ * CONFIG_UNLOCKED).
+ */
+void iommufd_device_tsm_unbind(struct iommufd_device *idev)
+{
+ mutex_lock(&idev->igroup->lock);
+ if (!idev->vdev) {
+ mutex_unlock(&idev->igroup->lock);
+ return;
+ }
+
+ iommufd_vdevice_tsm_unbind(idev->vdev);
+ refcount_dec(&idev->vdev->obj.users);
+ idev->vdev = NULL;
+ mutex_unlock(&idev->igroup->lock);
+
+ refcount_dec(&idev->obj.users);
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_device_tsm_unbind, "IOMMUFD");
diff --git a/drivers/iommu/iommufd/iommufd_private.h
b/drivers/iommu/iommufd/iommufd_private.h
index 297e4e2a12d1..29af8616e4aa 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -430,6 +430,7 @@ struct iommufd_device {
/* protect iopf_enabled counter */
struct mutex iopf_lock;
unsigned int iopf_enabled;
+ struct iommufd_vdevice *vdev;
};
static inline struct iommufd_device *
@@ -615,8 +616,13 @@ struct iommufd_vdevice {
struct iommufd_viommu *viommu;
struct device *dev;
u64 id; /* per-vIOMMU virtual ID */
+ struct mutex tsm_lock;
+ bool tsm_bound;
};
+int iommufd_vdevice_tsm_bind(struct iommufd_vdevice *vdev);
+void iommufd_vdevice_tsm_unbind(struct iommufd_vdevice *vdev);
+
#ifdef CONFIG_IOMMUFD_TEST
int iommufd_test(struct iommufd_ucmd *ucmd);
void iommufd_selftest_destroy(struct iommufd_object *obj);
diff --git a/drivers/iommu/iommufd/viommu.c b/drivers/iommu/iommufd/viommu.c
index 2fcef3f8d1a5..296143e21368 100644
--- a/drivers/iommu/iommufd/viommu.c
+++ b/drivers/iommu/iommufd/viommu.c
@@ -4,6 +4,7 @@
#if IS_ENABLED(CONFIG_KVM)
#include <linux/kvm_host.h>
#endif
+#include <linux/pci-tsm.h>
#include "iommufd_private.h"
@@ -193,11 +194,13 @@ int iommufd_vdevice_alloc_ioctl(struct iommufd_ucmd *ucmd)
goto out_put_idev;
}
+ vdev->ictx = ucmd->ictx; //This is a unrelated fix for vdevice alloc
vdev->id = virt_id;
vdev->dev = idev->dev;
get_device(idev->dev);
vdev->viommu = viommu;
refcount_inc(&viommu->obj.users);
+ mutex_init(&vdev->tsm_lock);
curr = xa_cmpxchg(&viommu->vdevs, virt_id, NULL, vdev, GFP_KERNEL);
if (curr) {
@@ -220,3 +223,44 @@ int iommufd_vdevice_alloc_ioctl(struct iommufd_ucmd *ucmd)
iommufd_put_object(ucmd->ictx, &viommu->obj);
return rc;
}
+
+int iommufd_vdevice_tsm_bind(struct iommufd_vdevice *vdev)
+{
+ struct kvm *kvm;
+ int rc;
+
+ mutex_lock(&vdev->tsm_lock);
+ if (vdev->tsm_bound) {
+ rc = -EEXIST;
+ goto out_unlock;
+ }
+
+ kvm = vdev->viommu->kvm;
+ if (!kvm) {
+ rc = -ENOENT;
+ goto out_unlock;
+ }
+
+ rc = pci_tsm_bind(to_pci_dev(vdev->dev), kvm, vdev->id);
+ if (rc)
+ goto out_unlock;
+
+ vdev->tsm_bound = true;
+
+out_unlock:
+ mutex_unlock(&vdev->tsm_lock);
+ return rc;
+}
+
+void iommufd_vdevice_tsm_unbind(struct iommufd_vdevice *vdev)
+{
+ mutex_lock(&vdev->tsm_lock);
+ if (!vdev->tsm_bound)
+ goto out_unlock;
+
+ pci_tsm_unbind(to_pci_dev(vdev->dev));
+ vdev->tsm_bound = false;
+
+out_unlock:
+ mutex_unlock(&vdev->tsm_lock);
+}
diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h
index 2712421802b9..5f9a286232ac 100644
--- a/include/linux/iommufd.h
+++ b/include/linux/iommufd.h
@@ -63,6 +63,9 @@ int iommufd_device_replace(struct iommufd_device *idev,
ioasid_t pasid,
u32 *pt_id);
void iommufd_device_detach(struct iommufd_device *idev, ioasid_t pasid);
+int iommufd_device_tsm_bind(struct iommufd_device *idev, u32 vdevice_id);
+void iommufd_device_tsm_unbind(struct iommufd_device *idev);
+
struct iommufd_ctx *iommufd_device_to_ictx(struct iommufd_device *idev);
u32 iommufd_device_to_id(struct iommufd_device *idev);
--
2.25.1
