+
+ /* Get a file descriptor for the device */
+ device = ioctl(group, VFIO_GROUP_GET_DEVICE_FD, "0000:06:0d.0");
+
+ ....
+
+ /* Gratuitous device reset and go... */
+ ioctl(device, VFIO_DEVICE_RESET);
+
+ /* Make sure EEH is supported */
+ ioctl(container, VFIO_CHECK_EXTENSION, VFIO_EEH);
+
+ /* Enable the EEH functionality on the device */
+ pe_op.op = VFIO_EEH_PE_ENABLE;
+ ioctl(container, VFIO_EEH_PE_OP, &pe_op);
+
+ /* You're suggested to create additional data struct to represent
+ * PE, and put child devices belonging to same IOMMU group to the
+ * PE instance for later reference.
+ */
+
+ /* Check the PE's state and make sure it's in functional state */
+ pe_op.op = VFIO_EEH_PE_GET_STATE;
+ ioctl(container, VFIO_EEH_PE_OP, &pe_op);
+
+ /* Save device state using pci_save_state().
+ * EEH should be enabled on the specified device.
+ */
+
+ ....
+
+ /* When 0xFF's returned from reading PCI config space or IO BARs
+ * of the PCI device. Check the PE's state to see if that has been
+ * frozen.
+ */
+ ioctl(container, VFIO_EEH_PE_OP, &pe_op);
+
+ /* Waiting for pending PCI transactions to be completed and don't
+ * produce any more PCI traffic from/to the affected PE until
+ * recovery is finished.
+ */
+
+ /* Enable IO for the affected PE and collect logs. Usually, the
+ * standard part of PCI config space, AER registers are dumped
+ * as logs for further analysis.
+ */
+ pe_op.op = VFIO_EEH_PE_UNFREEZE_IO;
+ ioctl(container, VFIO_EEH_PE_OP, &pe_op);
+
+ /*
+ * Issue PE reset: hot or fundamental reset. Usually, hot reset
+ * is enough. However, the firmware of some PCI adapters would
+ * require fundamental reset.
+ */
+ pe_op.op = VFIO_EEH_PE_RESET_HOT;
+ ioctl(container, VFIO_EEH_PE_OP, &pe_op);
+ pe_op.op = VFIO_EEH_PE_RESET_DEACTIVATE;
+ ioctl(container, VFIO_EEH_PE_OP, &pe_op);
+
+ /* Configure the PCI bridges for the affected PE */
+ pe_op.op = VFIO_EEH_PE_CONFIGURE;
+ ioctl(container, VFIO_EEH_PE_OP, &pe_op);
+
+ /* Restored state we saved at initialization time. pci_restore_state()
+ * is good enough as an example.
+ */
+
+ /* Hopefully, error is recovered successfully. Now, you can resume to
+ * start PCI traffic to/from the affected PE.
+ */
+
+ ....