Jason Wang
2020-Dec-01 06:25 UTC
[External] Re: [PATCH 0/7] Introduce vdpa management tool
On 2020/11/30 ??3:07, Yongji Xie wrote:>>> Thanks for adding me, Jason! >>> >>> Now I'm working on a v2 patchset for VDUSE (vDPA Device in Userspace) >>> [1]. This tool is very useful for the vduse device. So I'm considering >>> integrating this into my v2 patchset. But there is one problem? >>> >>> In this tool, vdpa device config action and enable action are combined >>> into one netlink msg: VDPA_CMD_DEV_NEW. But in vduse case, it needs to >>> be splitted because a chardev should be created and opened by a >>> userspace process before we enable the vdpa device (call >>> vdpa_register_device()). >>> >>> So I'd like to know whether it's possible (or have some plans) to add >>> two new netlink msgs something like: VDPA_CMD_DEV_ENABLE and >>> VDPA_CMD_DEV_DISABLE to make the config path more flexible. >>> >> Actually, we've discussed such intermediate step in some early >> discussion. It looks to me VDUSE could be one of the users of this. >> >> Or I wonder whether we can switch to use anonymous inode(fd) for VDUSE >> then fetching it via an VDUSE_GET_DEVICE_FD ioctl? >> > Yes, we can. Actually the current implementation in VDUSE is like > this. But seems like this is still a intermediate step. The fd should > be binded to a name or something else which need to be configured > before.The name could be specified via the netlink. It looks to me the real issue is that until the device is connected with a userspace, it can't be used. So we also need to fail the enabling if it doesn't opened. Thanks> > Thanks, > Yongji >