vDPA: report virtio-block max segment size to user space

This commit allows reporting the max size of any
single segment of virtio-block devices to user space.

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Message-Id: <20240218185606.13509-3-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index 613bec31f59e1ca73f241519c9999b4b1dc55858..db355d4683bac069638f7693b75b3f401b0baac4 100644 (file)
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -956,6 +956,20 @@ vdpa_dev_blk_capacity_config_fill(struct sk_buff *msg,
                                 val_u64, VDPA_ATTR_PAD);
 }
 
+static int
+vdpa_dev_blk_seg_size_config_fill(struct sk_buff *msg, u64 features,
+                                 const struct virtio_blk_config *config)
+{
+       u32 val_u32;
+
+       if ((features & BIT_ULL(VIRTIO_BLK_F_SIZE_MAX)) == 0)
+               return 0;
+
+       val_u32 = __virtio32_to_cpu(true, config->size_max);
+
+       return nla_put_u32(msg, VDPA_ATTR_DEV_BLK_CFG_SEG_SIZE, val_u32);
+}
+
 static int vdpa_dev_blk_config_fill(struct vdpa_device *vdev,
                                    struct sk_buff *msg)
 {
@@ -973,6 +987,9 @@ static int vdpa_dev_blk_config_fill(struct vdpa_device *vdev,
        if (vdpa_dev_blk_capacity_config_fill(msg, &config))
                return -EMSGSIZE;
 
+       if (vdpa_dev_blk_seg_size_config_fill(msg, features_device, &config))
+               return -EMSGSIZE;
+
        return 0;
 }
 

diff --git a/include/uapi/linux/vdpa.h b/include/uapi/linux/vdpa.h
index 1bf69226cb96fcd8b1f536cfee652cb8d415a7ff..586bce3c906a8eb6c31db5d8d4ecf8a94ce76c79 100644 (file)
--- a/include/uapi/linux/vdpa.h
+++ b/include/uapi/linux/vdpa.h
@@ -57,6 +57,7 @@ enum vdpa_attr {
        VDPA_ATTR_DEV_FEATURES,                 /* u64 */
 
        VDPA_ATTR_DEV_BLK_CFG_CAPACITY,         /* u64 */
+       VDPA_ATTR_DEV_BLK_CFG_SEG_SIZE,         /* u32 */
 
        /* new attributes must be added above here */
        VDPA_ATTR_MAX,