[dpdk-dev] [PATCH v3 0/7] virtio_user as an alternative exception path
bruce.richardson at intel.com
Mon Jan 9 15:06:34 CET 2017
On Wed, Jan 04, 2017 at 03:59:19AM +0000, Jianfeng Tan wrote:
> - Drop the patch to postpone driver ok sending patch, superseded it
> with a bug fix to disable all virtqueues and re-init the device.
> (you might wonder why not just send reset owner msg. Under my test,
> it causes spinlock deadlock problem when killing the program).
> - Avoid compiling error on 32-bit system for pointer convert.
> - Fix a bug in patch "abstract virtio user backend ops", vhostfd is
> not properly assigned.
> - Fix a "MQ cannot be used" bug in v2, which is related to strip
> some feature bits that vhost kernel does not recognize.
> - Update release note.
> v2: (Lots of them are from yuanhan's comment)
> - Add offloding feature.
> - Add multiqueue support.
> - Add a new patch to postpone the sending of driver ok notification.
> - Put fix patch ahead of the whole patch series.
> - Split original 0001 patch into 0003 and 0004 patches.
> - Remove the original vhost_internal design, just add those into
> struct virtio_user_dev for simplicity.
> - Reword "control" to "send_request".
> - Reword "host_features" to "device_features".
> In v16.07, we upstreamed a virtual device, virtio_user (with vhost-user
> as the backend). The path to go with a vhost-kernel backend has been
> dropped for bad performance comparing to vhost-user and code simplicity.
> But after a second thought, virtio_user + vhost-kernel is a good
> candidate as an exceptional path, such as KNI, which exchanges packets
> with kernel networking stack.
> - maintenance: vhost-net (kernel) is upstreamed and extensively used
> kernel module. We don't need any out-of-tree module like KNI.
> - performance: as with KNI, this solution would use one or more
> kthreads to send/receive packets from user space DPDK applications,
> which has little impact on user space polling thread (except that
> it might enter into kernel space to wake up those kthreads if
> - features: vhost-net is born to be a networking solution, which has
> lots of networking related featuers, like multi queue, tso, multi-seg
> mbuf, etc.
> Signed-off-by: Jianfeng Tan <jianfeng.tan at intel.com>
Sounds great. However, I think we'll need a how-to doc for this to help
people get it up and running as a KNI replacement for packets to/from
the kernel. Any plans to draw up such a doc? It would be good to include
it in this patchset.
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