Support serious device error recovery
Signed-off-by: Cao jin <caoj.fnst@xxxxxxxxxxxxxx>
---
drivers/vfio/pci/vfio_pci.c | 70 +++++++++++++++++++++++++++++++++++--
drivers/vfio/pci/vfio_pci_private.h | 2 ++
2 files changed, 70 insertions(+), 2 deletions(-)
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 712a849..752af20 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -534,6 +534,15 @@ static long vfio_pci_ioctl(void *device_data,
{
struct vfio_pci_device *vdev = device_data;
unsigned long minsz;
+ int ret;
+
+ if (vdev->aer_recovering && (cmd == VFIO_DEVICE_SET_IRQS ||
+ cmd == VFIO_DEVICE_RESET || cmd == VFIO_DEVICE_PCI_HOT_RESET)) {
+ ret = wait_for_completion_interruptible(
+ &vdev->aer_completion);
+ if (ret)
+ return ret;
+ }
if (cmd == VFIO_DEVICE_GET_INFO) {
struct vfio_device_info info;
@@ -953,6 +962,15 @@ static ssize_t vfio_pci_rw(void *device_data, char __user *buf,
{
unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
struct vfio_pci_device *vdev = device_data;
+ int ret;
+
+ /* block all kinds of access during host recovery */
+ if (vdev->aer_recovering) {
+ ret = wait_for_completion_interruptible(
+ &vdev->aer_completion);
+ if (ret)
+ return ret;
+ }
if (index >= VFIO_PCI_NUM_REGIONS + vdev->num_regions)
return -EINVAL;
@@ -1117,6 +1135,7 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
vdev->irq_type = VFIO_PCI_NUM_IRQS;
mutex_init(&vdev->igate);
spin_lock_init(&vdev->irqlock);
+ init_completion(&vdev->aer_completion);
ret = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev);
if (ret) {
@@ -1176,6 +1195,9 @@ static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev,
{
struct vfio_pci_device *vdev;
struct vfio_device *device;
+ u32 uncor_status;
+ unsigned int aer_cap_offset;
+ int ret;
device = vfio_device_get_from_dev(&pdev->dev);
if (device == NULL)
@@ -1187,10 +1209,29 @@ static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev,
return PCI_ERS_RESULT_DISCONNECT;
}
+ /*
+ * get device's uncorrectable error status as soon as possible,
+ * and signal it to user space. The later we read it, the possibility
+ * the register value is mangled grows.
+ */
+ aer_cap_offset = pci_find_ext_capability(vdev->pdev, PCI_EXT_CAP_ID_ERR);
+ ret = pci_read_config_dword(vdev->pdev, aer_cap_offset +
+ PCI_ERR_UNCOR_STATUS, &uncor_status);
+ if (ret)
+ return PCI_ERS_RESULT_DISCONNECT;
+
+ pr_info("device %d got AER detect notification. uncorrectable error status = 0x%x\n", pdev->devfn, uncor_status);//to be removed
mutex_lock(&vdev->igate);
- if (vdev->err_trigger)
- eventfd_signal(vdev->err_trigger, 1);
+ vdev->aer_recovering = true;
+ reinit_completion(&vdev->aer_completion);
+
+ if (vdev->err_trigger && uncor_status) {
+ pr_info("device %d signal uncor status 0x%x to user",
+ pdev->devfn, uncor_status);
+ /* signal uncorrectable error status to user space */
+ eventfd_signal(vdev->err_trigger, uncor_status);
+ }
mutex_unlock(&vdev->igate);
@@ -1199,8 +1240,33 @@ static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev,
return PCI_ERS_RESULT_CAN_RECOVER;
}
+static void vfio_pci_aer_resume(struct pci_dev *pdev)
+{
+ struct vfio_pci_device *vdev;
+ struct vfio_device *device;
+
+ device = vfio_device_get_from_dev(&pdev->dev);
+ if (device == NULL)
+ return;
+
+ vdev = vfio_device_data(device);
+ if (vdev == NULL) {
+ vfio_device_put(device);
+ return;
+ }
+
+ mutex_lock(&vdev->igate);
+ vdev->aer_recovering = false;
+ mutex_unlock(&vdev->igate);
+
+ complete_all(&vdev->aer_completion);
+
+ vfio_device_put(device);
+}
+
static const struct pci_error_handlers vfio_err_handlers = {
.error_detected = vfio_pci_aer_err_detected,
+ .resume = vfio_pci_aer_resume,
};
static struct pci_driver vfio_pci_driver = {
diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h
index 8a7d546..ba8471f 100644
--- a/drivers/vfio/pci/vfio_pci_private.h
+++ b/drivers/vfio/pci/vfio_pci_private.h
@@ -83,6 +83,8 @@ struct vfio_pci_device {
bool bardirty;
bool has_vga;
bool needs_reset;
+ bool aer_recovering;
+ struct completion aer_completion;
struct pci_saved_state *pci_saved_state;
int refcnt;
struct eventfd_ctx *err_trigger;
--
1.8.3.1
--
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