@@ -733,6 +733,35 @@ static int blkio_virtio_blk_connect(BlockDriverState *bs, QDict *options,
}
ret = blkio_connect(s->blkio);
+ /*
+ * If the libblkio driver doesn't support the `fd` property, blkio_connect()
+ * will fail with -EINVAL. So let's try calling blkio_connect() again by
+ * directly setting `path`.
+ */
+ if (fd_supported && ret == -EINVAL) {
+ qemu_close(fd);
+
+ /*
+ * We need to clear the `fd` property we set previously by setting
+ * it to -1.
+ */
+ ret = blkio_set_int(s->blkio, "fd", -1);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "failed to set fd: %s",
+ blkio_get_error_msg());
+ return ret;
+ }
+
+ ret = blkio_set_str(s->blkio, "path", path);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "failed to set path: %s",
+ blkio_get_error_msg());
+ return ret;
+ }
+
+ ret = blkio_connect(s->blkio);
+ }
+
if (ret < 0) {
error_setg_errno(errp, -ret, "blkio_connect failed: %s",
blkio_get_error_msg());
libblkio 1.3.0 added support of "fd" property for virtio-blk-vhost-vdpa driver. In QEMU, starting from commit cad2ccc395 ("block/blkio: use qemu_open() to support fd passing for virtio-blk") we are using `blkio_get_int(..., "fd")` to check if the "fd" property is supported for all the virtio-blk-* driver. Unfortunately that property is also available for those driver that do not support it, such as virtio-blk-vhost-user. So, `blkio_get_int()` is not enough to check whether the driver supports the `fd` property or not. This is because the virito-blk common libblkio driver only checks whether or not `fd` is set during `blkio_connect()` and fails with -EINVAL for those transports that do not support it (all except vhost-vdpa for now). So let's handle the `blkio_connect()` failure, retrying it using `path` directly. Fixes: cad2ccc395 ("block/blkio: use qemu_open() to support fd passing for virtio-blk") Suggested-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> --- Notes: v2: - reworked retrying blkio_connect() [Stefan] block/blkio.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+)