[PATCH] vfio-pci: report recovery event after device recovery successful

[Hogan Wang <hogan.wang@huawei.com>]

As you all know, device faults are classified into the following
types: unrecoverable error and recoverable error. vfio-pci drvier
will report error event to user-space process while device occur
hardware errors, and still report the other error event after deivce
recovery successful. So the user-space process just like qemu can not
identify the event is an hardware error event or a device recovery
successful event. So in order to solve this problem, add an eventfd
named recov_trigger to report device recovery successful event, the
user-space process can make a decision whether to process the recovery
event or not.

Signed-off-by: Hogan Wang <hogan.wang@huawei.com>
---
 drivers/vfio/pci/vfio_pci_core.c  | 13 +++++++++++--
 drivers/vfio/pci/vfio_pci_intrs.c | 19 +++++++++++++++++++
 include/linux/vfio_pci_core.h     |  1 +
 include/uapi/linux/vfio.h         |  1 +
 4 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index b7bb16f92ac6..2360cb44aa36 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -483,6 +483,10 @@ void vfio_pci_core_close_device(struct vfio_device *core_vdev)
 		eventfd_ctx_put(vdev->err_trigger);
 		vdev->err_trigger = NULL;
 	}
+	if (vdev->recov_trigger) {
+		eventfd_ctx_put(vdev->recov_trigger);
+		vdev->recov_trigger = NULL;
+	}
 	if (vdev->req_trigger) {
 		eventfd_ctx_put(vdev->req_trigger);
 		vdev->req_trigger = NULL;
@@ -1922,8 +1926,13 @@ pci_ers_result_t vfio_pci_core_aer_err_detected(struct pci_dev *pdev,
 
 	mutex_lock(&vdev->igate);
 
-	if (vdev->err_trigger)
-		eventfd_signal(vdev->err_trigger, 1);
+	if (state == pci_channel_io_normal) {
+		if (vdev->recov_trigger)
+			eventfd_signal(vdev->recov_trigger, 1);
+	} else {
+		if (vdev->err_trigger)
+			eventfd_signal(vdev->err_trigger, 1);
+	}
 
 	mutex_unlock(&vdev->igate);
 
diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c
index 6069a11fb51a..be76ff76c361 100644
--- a/drivers/vfio/pci/vfio_pci_intrs.c
+++ b/drivers/vfio/pci/vfio_pci_intrs.c
@@ -624,6 +624,17 @@ static int vfio_pci_set_err_trigger(struct vfio_pci_core_device *vdev,
 					       count, flags, data);
 }
 
+static int vfio_pci_set_recov_trigger(struct vfio_pci_core_device *vdev,
+				    unsigned index, unsigned start,
+				    unsigned count, uint32_t flags, void *data)
+{
+	if (index != VFIO_PCI_ERR_IRQ_INDEX || start != 0 || count > 1)
+		return -EINVAL;
+
+	return vfio_pci_set_ctx_trigger_single(&vdev->recov_trigger,
+					       count, flags, data);
+}
+
 static int vfio_pci_set_req_trigger(struct vfio_pci_core_device *vdev,
 				    unsigned index, unsigned start,
 				    unsigned count, uint32_t flags, void *data)
@@ -684,6 +695,14 @@ int vfio_pci_set_irqs_ioctl(struct vfio_pci_core_device *vdev, uint32_t flags,
 			break;
 		}
 		break;
+	case VFIO_PCI_RECOV_IRQ_INDEX:
+		switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
+		case VFIO_IRQ_SET_ACTION_TRIGGER:
+			if (pci_is_pcie(vdev->pdev))
+				func = vfio_pci_set_recov_trigger;
+			break;
+		}
+		break;
 	}
 
 	if (!func)
diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h
index 74a4a0f17b28..d94addb18118 100644
--- a/include/linux/vfio_pci_core.h
+++ b/include/linux/vfio_pci_core.h
@@ -128,6 +128,7 @@ struct vfio_pci_core_device {
 	struct pci_saved_state	*pm_save;
 	int			ioeventfds_nr;
 	struct eventfd_ctx	*err_trigger;
+	struct eventfd_ctx	*recov_trigger;
 	struct eventfd_ctx	*req_trigger;
 	struct list_head	dummy_resources_list;
 	struct mutex		ioeventfds_lock;
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index fea86061b44e..f88a6ca62c49 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -621,6 +621,7 @@ enum {
 	VFIO_PCI_MSIX_IRQ_INDEX,
 	VFIO_PCI_ERR_IRQ_INDEX,
 	VFIO_PCI_REQ_IRQ_INDEX,
+	VFIO_PCI_RECOV_IRQ_INDEX,
 	VFIO_PCI_NUM_IRQS
 };
 
-- 
2.33.0