VFS: Unable to mount root fs on unknown-block

[ 1.736146] List of all partitions:
[ 1.736921] fd00 256000 vda
[ 1.736928] driver: virtio_blk
[ 1.737723] No filesystem could mount root, tried:
[ 1.737723]
[ 1.738136] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(253,0)
[ 1.738660] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.4.0-rc2+ #49
[ 1.739073] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 1.739582] Call Trace:
[ 1.739740]
[ 1.739875] dump_stack_lvl+0x32/0x50
[ 1.740105] panic+0x108/0x310
[ 1.740297] mount_block_root+0x179/0x2c0
[ 1.740547] ? rdinit_setup+0x40/0x40
[ 1.740769] prepare_namespace+0x10c/0x180
[ 1.741017] kernel_init_freeable+0x354/0x450
[ 1.741327] ? rest_init+0xd0/0xd0
[ 1.741552] kernel_init+0x16/0x130
[ 1.741784] ret_from_fork+0x1f/0x30
[ 1.742018]
[ 1.742319] Kernel Offset: 0x17e00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[ 1.743034] ---[ end Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(253,0) ]---

这种问题要看对应的挂载的文件系统是否被buildin，或者能被模块找到。