[PATCH v5 08/14] iommufd/viommu: Add iommufd_viommu_report_event helper

Nicolin Chen
2025-01-07T17:11:15Z

Similar to iommu_report_device_fault, this allows IOMMU drivers to report
vIOMMU events from threaded IRQ handlers to user space hypervisors.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
include/linux/iommufd.h | 11 +++++++++
drivers/iommu/iommufd/driver.c | 43 ++++++++++++++++++++++++++++++++++
2 files changed, 54 insertions(+)

diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h
index a6dd9f8edcf3..55e71dca3664 100644
--- a/include/linux/iommufd.h
+++ b/include/linux/iommufd.h
@@ -11,6 +11,7 @@
#include <linux/refcount.h>
#include <linux/types.h>
#include <linux/xarray.h>
+#include <uapi/linux/iommufd.h>

struct device;
struct file;
@@ -194,6 +195,9 @@ struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu,
unsigned long vdev_id);
unsigned long iommufd_viommu_get_vdev_id(struct iommufd_viommu *viommu,
struct device *dev);
+int iommufd_viommu_report_event(struct iommufd_viommu *viommu,
+ enum iommu_veventq_type type, void *event_data,
+ size_t data_len);
#else /* !CONFIG_IOMMUFD_DRIVER_CORE */
static inline struct iommufd_object *
_iommufd_object_alloc(struct iommufd_ctx *ictx, size_t size,
@@ -213,6 +217,13 @@ iommufd_viommu_get_vdev_id(struct iommufd_viommu *viommu, struct device *dev)
{
return 0;
}
+
+static inline int iommufd_viommu_report_event(struct iommufd_viommu *viommu,
+ enum iommu_veventq_type type,
+ void *event_data, size_t data_len)
+{
+ return -EOPNOTSUPP;
+}
#endif /* CONFIG_IOMMUFD_DRIVER_CORE */

/*
diff --git a/drivers/iommu/iommufd/driver.c b/drivers/iommu/iommufd/driver.c
index e5d7397c0a6c..b03ceb016bee 100644
--- a/drivers/iommu/iommufd/driver.c
+++ b/drivers/iommu/iommufd/driver.c
@@ -69,5 +69,48 @@ unsigned long iommufd_viommu_get_vdev_id(struct iommufd_viommu *viommu,
}
EXPORT_SYMBOL_NS_GPL(iommufd_viommu_get_vdev_id, "IOMMUFD");

+/*
+ * Typically called in driver's threaded IRQ handler.
+ * The @type and @event_data must be defined in include/uapi/linux/iommufd.h
+ */
+int iommufd_viommu_report_event(struct iommufd_viommu *viommu,
+ enum iommu_veventq_type type, void *event_data,
+ size_t data_len)
+{
+ struct iommufd_veventq *veventq;
+ struct iommufd_vevent *vevent;
+ int rc = 0;
+
+ if (!viommu)
+ return -ENODEV;
+ if (WARN_ON_ONCE(!viommu->ops || !viommu->ops->supports_veventq ||
+ !viommu->ops->supports_veventq(type)))
+ return -EOPNOTSUPP;
+ if (WARN_ON_ONCE(!data_len || !event_data))
+ return -EINVAL;
+
+ down_read(&viommu->veventqs_rwsem);
+
+ veventq = iommufd_viommu_find_veventq(viommu, type);
+ if (!veventq) {
+ rc = -EOPNOTSUPP;
+ goto out_unlock_veventqs;
+ }
+
+ vevent = kmalloc(struct_size(vevent, event_data, data_len), GFP_KERNEL);
+ if (!vevent) {
+ rc = -ENOMEM;
+ goto out_unlock_veventqs;
+ }
+ memcpy(vevent->event_data, event_data, data_len);
+ vevent->data_len = data_len;
+
+ iommufd_vevent_handler(veventq, vevent);
+out_unlock_veventqs:
+ up_read(&viommu->veventqs_rwsem);
+ return rc;
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_viommu_report_event, "IOMMUFD");
+
MODULE_DESCRIPTION("iommufd code shared with builtin modules");
MODULE_LICENSE("GPL");
--
2.43.0