vDPA: report virtio-block discarding configuration to user space

This commit reports virtio-blk discarding configuration
to user space,includes:
1) the maximum discard sectors
2) maximum number of discard segments for the block driver to use
3) the alignment for splitting a discarding request

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Message-Id: <20240218185606.13509-8-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 76b2e31d6229a75f3d39148f308a1cd191982e53..9348818b8bf9d313b7dbecc8a563125cfa5e2dfd 100644 (file)
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -1041,6 +1041,29 @@ static int vdpa_dev_blk_topology_config_fill(struct sk_buff *msg, u64 features,
        return 0;
 }
 
+static int vdpa_dev_blk_discard_config_fill(struct sk_buff *msg, u64 features,
+                                      const struct virtio_blk_config *config)
+{
+       u32 val_u32;
+
+       if ((features & BIT_ULL(VIRTIO_BLK_F_DISCARD)) == 0)
+               return 0;
+
+       val_u32 = __virtio32_to_cpu(true, config->max_discard_sectors);
+       if (nla_put_u32(msg, VDPA_ATTR_DEV_BLK_CFG_MAX_DISCARD_SEC, val_u32))
+               return -EMSGSIZE;
+
+       val_u32 = __virtio32_to_cpu(true, config->max_discard_seg);
+       if (nla_put_u32(msg, VDPA_ATTR_DEV_BLK_CFG_MAX_DISCARD_SEG, val_u32))
+               return -EMSGSIZE;
+
+       val_u32 = __virtio32_to_cpu(true, config->discard_sector_alignment);
+       if (nla_put_u32(msg, VDPA_ATTR_DEV_BLK_CFG_DISCARD_SEC_ALIGN, val_u32))
+               return -EMSGSIZE;
+
+       return 0;
+}
+
 static int vdpa_dev_blk_config_fill(struct vdpa_device *vdev,
                                    struct sk_buff *msg)
 {
@@ -1073,6 +1096,9 @@ static int vdpa_dev_blk_config_fill(struct vdpa_device *vdev,
        if (vdpa_dev_blk_topology_config_fill(msg, features_device, &config))
                return -EMSGSIZE;
 
+       if (vdpa_dev_blk_discard_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 5cc70614c97a624fb2af17b35462c26e8150f435..30887931a2208727910431c2c4e7052d94135e7d 100644 (file)
--- a/include/uapi/linux/vdpa.h
+++ b/include/uapi/linux/vdpa.h
@@ -65,6 +65,9 @@ enum vdpa_attr {
        VDPA_ATTR_DEV_BLK_CFG_ALIGN_OFFSET,     /* u8 */
        VDPA_ATTR_DEV_BLK_CFG_MIN_IO_SIZE,      /* u16 */
        VDPA_ATTR_DEV_BLK_CFG_OPT_IO_SIZE,      /* u32 */
+       VDPA_ATTR_DEV_BLK_CFG_MAX_DISCARD_SEC,  /* u32 */
+       VDPA_ATTR_DEV_BLK_CFG_MAX_DISCARD_SEG,  /* u32 */
+       VDPA_ATTR_DEV_BLK_CFG_DISCARD_SEC_ALIGN,/* u32 */
 
        /* new attributes must be added above here */
        VDPA_ATTR_MAX,