Re: [dpdk-dev] [PATCH 07/10] vdpa/sfc: add support to get queue notify area info

From: Vijay Kumar Srivastava <redacted>

Implement the vDPA ops get_notify_area to get the notify
area info of the queue.

Signed-off-by: Vijay Kumar Srivastava <redacted>
---
 drivers/vdpa/sfc/sfc_vdpa_ops.c | 166 ++++++++++++++++++++++++++++++++++++++--
 drivers/vdpa/sfc/sfc_vdpa_ops.h |   2 +
 2 files changed, 162 insertions(+), 6 deletions(-)

diff --git a/drivers/vdpa/sfc/sfc_vdpa_ops.c b/drivers/vdpa/sfc/sfc_vdpa_ops.c

+static int
+sfc_vdpa_get_notify_area(int vid, int qid, uint64_t *offset, uint64_t *size)
+{
+	int ret;
+	efx_nic_t *nic;
+	int vfio_dev_fd;
+	efx_rc_t rc;
+	unsigned int bar_offset;
+	struct rte_vdpa_device *vdpa_dev;
+	struct sfc_vdpa_ops_data *ops_data;
+	struct vfio_region_info reg = { .argsz = sizeof(reg) };
+	const efx_nic_cfg_t *encp;
+	int max_vring_cnt;
+	int64_t len;
+	void *dev;
+
+	vdpa_dev = rte_vhost_get_vdpa_device(vid);
+
+	ops_data = sfc_vdpa_get_data_by_dev(vdpa_dev);
+	if (ops_data == NULL)
+		return -1;
+
+	dev = ops_data->dev_handle;
+
+	vfio_dev_fd = sfc_vdpa_adapter_by_dev_handle(dev)->vfio_dev_fd;
+	max_vring_cnt =
+		(sfc_vdpa_adapter_by_dev_handle(dev)->max_queue_count * 2);
+
+	nic = sfc_vdpa_adapter_by_dev_handle(ops_data->dev_handle)->nic;
+	encp = efx_nic_cfg_get(nic);
+
+	if (qid >= max_vring_cnt) {
+		sfc_vdpa_err(dev, "invalid qid : %d", qid);
+		return -1;
+	}
+
+	if (ops_data->vq_cxt[qid].enable != B_TRUE) {
+		sfc_vdpa_err(dev, "vq is not enabled");
+		return -1;
+	}
+
+	rc = efx_virtio_get_doorbell_offset(ops_data->vq_cxt[qid].vq,
+					    &bar_offset);
+	if (rc != 0) {
+		sfc_vdpa_err(dev, "failed to get doorbell offset: %s",
+			     rte_strerror(rc));
+		return rc;
+	}
+
+	reg.index = sfc_vdpa_adapter_by_dev_handle(dev)->mem_bar.esb_rid;
+	ret = ioctl(vfio_dev_fd, VFIO_DEVICE_GET_REGION_INFO, &reg);
+	if (ret != 0) {
+		sfc_vdpa_err(dev, "could not get device region info: %s",
+			     strerror(errno));
+		return ret;
+	}
+
+	*offset = reg.offset + bar_offset;
+
+	len = (1U << encp->enc_vi_window_shift) / 2;
+	if (len >= sysconf(_SC_PAGESIZE))
+		*size = sysconf(_SC_PAGESIZE);
+	else
+		return -1;

+
+	sfc_vdpa_info(dev, "vDPA ops get_notify_area :: offset : 0x%" PRIx64,
+		      *offset);
+
+	return 0;
+}
+