Re: [PATCH v13 00/13] Introduce VDUSE - vDPA Device in Userspace

[Liuxiangdong]

Hi, Yongji.

I tried vduse with null-blk:

  $ qemu-storage-daemon \
      --chardev socket,id=charmonitor,path=/tmp/qmp.sock,server,nowait \
      --monitor chardev=charmonitor \
      --blockdev 
driver=host_device,cache.direct=on,aio=native,filename=/dev/nullb0,node-name=disk0 
\
      --export 
type=vduse-blk,id=test,node-name=disk0,writable=on,name=vduse-null,num-queues=16,queue-size=128

The qemu-storage-daemon is yours 
(https://github.com/bytedance/qemu/tree/vduse)

And then, how can we use this vduse-null (dev/vduse/vduse-null) in vm(QEMU)?

Because qemu-storage-daemon open this vduse-null in vduse_dev_init(), 
all the operations which open this dev
will report "failed to open '/dev/vduse/vduse-null': Device or resource 
busy".

Or something I understood wrong?

Thanks!
Xiangdong Liu