ublk-qcow2 work with kvm guests

[ferodevil]

just like https://static.sched.com/hosted_files/kvmforum2020/9c/KVMForum_2020_io_uring_passthrough_Stefano_Garzarella.pdf, make io_uring SQ/CQ ring share between ublk-qcow2 and virtio-blk driver, to make performace best

[ming1]

Hello,

Can you explain a bit that this is one issue or improvement? Also I appreciate that you may provide more details.

Actually ublk-qcow2 has nothing in common with virtio-blk driver, not sure how to share io_uring. ublk-qcow2 backend is implemented totally in userspace with io_uring, and it does not use virtio-blk at all.

Thanks, Ming

[ferodevil]

hi,Ming

ublk-qcow2 or qemu-nbd used in host environment, and ublk-qcow2 result Better performance; how can it combine with qemu or virtual machine to make guest perform better?

1. replace qemu qcow2 logic？
2. just like spdk，share buffer with virtual machine？

Thanks

[ming1]

ublk-qcow2 is supposed to be used in host environment(such as container, ...), and not for guest.