[PATCH 10/10] vDPA: report virtio-blk flush info to user space

[Zhu Lingshan <lingshan.zhu@intel.com>]

This commit reports whether a virtio-blk device
support cache flush command to user space

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
---
 drivers/vdpa/vdpa.c       | 14 ++++++++++++++
 include/uapi/linux/vdpa.h |  1 +
 2 files changed, 15 insertions(+)

diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index d6fd3cadc44f..95e1440dbfaa 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -1095,6 +1095,17 @@ static int vdpa_dev_blk_ro_config_fill(struct sk_buff *msg, u64 features)
 	return 0;
 }
 
+static int vdpa_dev_blk_flush_config_fill(struct sk_buff *msg, u64 features)
+{
+	u8 flush;
+
+	flush = ((features & BIT_ULL(VIRTIO_BLK_F_FLUSH)) == 0) ? 0 : 1;
+	if (nla_put_u8(msg, VDPA_ATTR_DEV_BLK_CFG_FLUSH, flush))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
 static int vdpa_dev_blk_config_fill(struct vdpa_device *vdev,
 				    struct sk_buff *msg)
 {
@@ -1136,6 +1147,9 @@ static int vdpa_dev_blk_config_fill(struct vdpa_device *vdev,
 	if (vdpa_dev_blk_ro_config_fill(msg, features_device))
 		return -EMSGSIZE;
 
+	if (vdpa_dev_blk_flush_config_fill(msg, features_device))
+		return -EMSGSIZE;
+
 	return 0;
 }
 
diff --git a/include/uapi/linux/vdpa.h b/include/uapi/linux/vdpa.h
index 4be8e3a15874..43c51698195c 100644
--- a/include/uapi/linux/vdpa.h
+++ b/include/uapi/linux/vdpa.h
@@ -71,6 +71,7 @@ enum vdpa_attr {
 	VDPA_ATTR_DEV_BLK_CFG_MAX_WRITE_ZEROES_SEC,	/* u32 */
 	VDPA_ATTR_DEV_BLK_CFG_MAX_WRITE_ZEROES_SEG,	/* u32 */
 	VDPA_ATTR_DEV_BLK_CFG_READ_ONLY,		/* u8 */
+	VDPA_ATTR_DEV_BLK_CFG_FLUSH,		/* u8 */
 
 	/* new attributes must be added above here */
 	VDPA_ATTR_MAX,
-- 
2.39.3