From: Abhimanyu Saini <absa...@amd.com>
When DPDK app is running in the VF, it sometimes rings the doorbell
before dev_config has had a chance to complete and hence it misses
the event. As workaround, ring the doorbell when vDPA reports the
notify_area to QEMU.
Fixes: 5e7596ba7cb3 ("vdpa/sfc: introduce Xilinx vDPA driver")
Cc: sta...@dpdk.org
Signed-off-by: Vijay Kumar Srivastava <vsriv...@xilinx.com>
Signed-off-by: Abhimanyu Saini <absa...@amd.com>
---
drivers/vdpa/sfc/sfc_vdpa_ops.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/drivers/vdpa/sfc/sfc_vdpa_ops.c b/drivers/vdpa/sfc/sfc_vdpa_ops.c
index b3d9b6c..63aa52d 100644
--- a/drivers/vdpa/sfc/sfc_vdpa_ops.c
+++ b/drivers/vdpa/sfc/sfc_vdpa_ops.c
@@ -794,6 +794,8 @@
int vfio_dev_fd;
efx_rc_t rc;
unsigned int bar_offset;
+ volatile void *doorbell;
+ struct rte_pci_device *pci_dev;
struct rte_vdpa_device *vdpa_dev;
struct sfc_vdpa_ops_data *ops_data;
struct vfio_region_info reg = { .argsz = sizeof(reg) };
@@ -856,6 +858,18 @@
sfc_vdpa_info(dev, "vDPA ops get_notify_area :: offset : 0x%" PRIx64,
*offset);
+ pci_dev = sfc_vdpa_adapter_by_dev_handle(dev)->pdev;
+ doorbell = (uint8_t *)pci_dev->mem_resource[reg.index].addr + *offset;
+
+ /*
+ * virtio-net driver in VM sends queue notifications before
+ * vDPA has a chance to setup the queues and notification area,
+ * and hence the HW misses these doorbell notifications.
+ * Since, it is safe to send duplicate doorbell, send another
+ * doorbell from vDPA driver as workaround for this timing issue.
+ */
+ rte_write16(qid, doorbell);
+
return 0;
}
--
1.8.3.1
