[feature] support SPDK

[caiwenzh]

Why you need it?

vhost-user-blk/scsi. is a high efficient way to transport data for virtual environments. Open-local currently doesn't support vhost-user-blk/scsi.

How it could be?

The Storage Performance Development Kit (SPDK) can provide vhost support. To support vhost-user-blk/scsi in open-local node CSI driver should communicate with SPDK. Following is a brief description :

.  NodeStageVolume / NodeUnStageVolume
    n/a
.  NodePublishVolume
    -  Create bdev
        # scripts/rpc.py bdev_aio_create <path_to_host_block_dev> <bdev_name>
        # scripts/rpc.py bdev_lvol_create_lvstore <bdev_name> <lvs_name >
        # scripts/rpc.py bdev_lvol_create  <lvol_name> <size> -l <lvs_name>
    -  Create vhost device
        # scripts/rpc.py vhost_create_blk_controller --cpumask 0x1 vhostblk0 <bdev_name>
        # mknod /var/run/kata-containers/vhost-user/block/devices/vhostblk0 b 241 0
        # mount --bind [...] /var/run/kata-containers/vhost-user/block/devices/vhostblk0 <target_path>
.  NodeUnPublishVolume
       # umount <target_path>
       # scripts/rpc.py bdev_lvol_delete  <lvol_name>
       # rm /var/run/kata-containers/vhost-user/block/devices/vhostblk0

besides, we need add a field in nlsc and nls to indicate if the storage is provided by SPDK.

Other related information

[jiangliu]

It's a great idea to enable spdk for vm based container runtimes. BTW, does it work for native runC container runtime?

[caiwenzh]

It's a great idea to enable spdk for vm based container runtimes. BTW, does it work for native runC container runtime?
No. we only introduce SPDK vhost currently, so it doesn't support runC.

[caiwenzh]

SPDK also support network storage (iSCSI and NVME-oF). Need it to be supported?

[jiangliu]

SPDK also support network storage (iSCSI and NVME-oF). Need it to be supported?

NVME-OF is great，especially with ns support. We could do much things funny with NVME ns.

[jiangliu]

It's a great idea to enable spdk for vm based container runtimes. BTW, does it work for native runC container runtime?
No. we only introduce SPDK vhost currently, so it doesn't support runC.

Thanks for explanation, that makes sense.

[TheBeatles1994]

fixed by #153