[PATCH v4 6/7] vdpa: add new attribute VDPA_ATTR_DEV_MIN_VQ_SIZE

[Wu Zongyong <wuzongyong@linux.alibaba.com>]

This attribute advertises the min value of virtqueue size. The value is
0 by default.

Signed-off-by: Wu Zongyong <wuzongyong@linux.alibaba.com>
---
 drivers/vdpa/vdpa.c       | 5 +++++
 include/uapi/linux/vdpa.h | 1 +
 2 files changed, 6 insertions(+)

diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index 1dc121a07a93..6ed79fba33e4 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -492,6 +492,7 @@ vdpa_dev_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, u32 seq
 	      int flags, struct netlink_ext_ack *extack)
 {
 	u16 max_vq_size;
+	u16 min_vq_size = 0;
 	u32 device_id;
 	u32 vendor_id;
 	void *hdr;
@@ -508,6 +509,8 @@ vdpa_dev_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, u32 seq
 	device_id = vdev->config->get_device_id(vdev);
 	vendor_id = vdev->config->get_vendor_id(vdev);
 	max_vq_size = vdev->config->get_vq_num_max(vdev);
+	if (vdev->config->get_vq_num_min)
+		min_vq_size = vdev->config->get_vq_num_min(vdev);
 
 	err = -EMSGSIZE;
 	if (nla_put_string(msg, VDPA_ATTR_DEV_NAME, dev_name(&vdev->dev)))
@@ -520,6 +523,8 @@ vdpa_dev_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, u32 seq
 		goto msg_err;
 	if (nla_put_u16(msg, VDPA_ATTR_DEV_MAX_VQ_SIZE, max_vq_size))
 		goto msg_err;
+	if (nla_put_u16(msg, VDPA_ATTR_DEV_MIN_VQ_SIZE, min_vq_size))
+		goto msg_err;
 
 	genlmsg_end(msg, hdr);
 	return 0;
diff --git a/include/uapi/linux/vdpa.h b/include/uapi/linux/vdpa.h
index 66a41e4ec163..e3b87879514c 100644
--- a/include/uapi/linux/vdpa.h
+++ b/include/uapi/linux/vdpa.h
@@ -32,6 +32,7 @@ enum vdpa_attr {
 	VDPA_ATTR_DEV_VENDOR_ID,		/* u32 */
 	VDPA_ATTR_DEV_MAX_VQS,			/* u32 */
 	VDPA_ATTR_DEV_MAX_VQ_SIZE,		/* u16 */
+	VDPA_ATTR_DEV_MIN_VQ_SIZE,		/* u16 */
 
 	/* new attributes must be added above here */
 	VDPA_ATTR_MAX,
-- 
2.31.1