[RFC] vhost: introduce mdev based hardware vhost backend

2018-04-02 Thread Tiwei Bie
This patch introduces a mdev (mediated device) based hardware vhost backend. This backend is an abstraction of the various hardware vhost accelerators (potentially any device that uses virtio ring can be used as a vhost accelerator). Some generic mdev parent ops are provided for accelerator drivers

Re: [RFC] vhost: introduce mdev based hardware vhost backend

2018-04-09 Thread Jason Wang
On 2018年04月02日 23:23, Tiwei Bie wrote: This patch introduces a mdev (mediated device) based hardware vhost backend. This backend is an abstraction of the various hardware vhost accelerators (potentially any device that uses virtio ring can be used as a vhost accelerator). Some generic mdev pare

Re: [RFC] vhost: introduce mdev based hardware vhost backend

2018-04-09 Thread Tiwei Bie
On Tue, Apr 10, 2018 at 10:52:52AM +0800, Jason Wang wrote: > On 2018年04月02日 23:23, Tiwei Bie wrote: > > This patch introduces a mdev (mediated device) based hardware > > vhost backend. This backend is an abstraction of the various > > hardware vhost accelerators (potentially any device that uses >

Re: [RFC] vhost: introduce mdev based hardware vhost backend

2018-04-10 Thread Jason Wang
On 2018年04月10日 12:57, Tiwei Bie wrote: On Tue, Apr 10, 2018 at 10:52:52AM +0800, Jason Wang wrote: On 2018年04月02日 23:23, Tiwei Bie wrote: This patch introduces a mdev (mediated device) based hardware vhost backend. This backend is an abstraction of the various hardware vhost accelerators (pot

Re: [RFC] vhost: introduce mdev based hardware vhost backend

2018-04-19 Thread Michael S. Tsirkin
On Tue, Apr 10, 2018 at 03:25:45PM +0800, Jason Wang wrote: > > > > One problem is that, different virtio ring compatible devices > > > > may have different device interfaces. That is to say, we will > > > > need different drivers in QEMU. It could be troublesome. And > > > > that's what this patch

Re: [RFC] vhost: introduce mdev based hardware vhost backend

2018-04-19 Thread Tiwei Bie
On Thu, Apr 19, 2018 at 09:40:23PM +0300, Michael S. Tsirkin wrote: > On Tue, Apr 10, 2018 at 03:25:45PM +0800, Jason Wang wrote: > > > > > One problem is that, different virtio ring compatible devices > > > > > may have different device interfaces. That is to say, we will > > > > > need different

Re: [RFC] vhost: introduce mdev based hardware vhost backend

2018-04-19 Thread Michael S. Tsirkin
On Fri, Apr 20, 2018 at 11:28:07AM +0800, Tiwei Bie wrote: > On Thu, Apr 19, 2018 at 09:40:23PM +0300, Michael S. Tsirkin wrote: > > On Tue, Apr 10, 2018 at 03:25:45PM +0800, Jason Wang wrote: > > > > > > One problem is that, different virtio ring compatible devices > > > > > > may have different d

RE: [RFC] vhost: introduce mdev based hardware vhost backend

2018-04-19 Thread Liang, Cunming
gt; k...@vger.kernel.org; virtualizat...@lists.linux-foundation.org; > netdev@vger.kernel.org; Daly, Dan ; Liang, Cunming > ; Wang, Zhihong ; Tan, > Jianfeng ; Wang, Xiao W ; > Tian, Kevin > Subject: Re: [RFC] vhost: introduce mdev based hardware vhost backend > > On Thu, Apr 19,

Re: [RFC] vhost: introduce mdev based hardware vhost backend

2018-04-19 Thread Jason Wang
On 2018年04月20日 02:40, Michael S. Tsirkin wrote: On Tue, Apr 10, 2018 at 03:25:45PM +0800, Jason Wang wrote: One problem is that, different virtio ring compatible devices may have different device interfaces. That is to say, we will need different drivers in QEMU. It could be troublesome. And t

Re: [RFC] vhost: introduce mdev based hardware vhost backend

2018-04-20 Thread Michael S. Tsirkin
edhat.com; Duyck, Alexander H ; > > virtio-...@lists.oasis-open.org; linux-ker...@vger.kernel.org; > > k...@vger.kernel.org; virtualizat...@lists.linux-foundation.org; > > netdev@vger.kernel.org; Daly, Dan ; Liang, Cunming > > ; Wang, Zhihong ; Tan, > > Jianfeng ; Wang

Re: [RFC] vhost: introduce mdev based hardware vhost backend

2018-04-20 Thread Michael S. Tsirkin
On Fri, Apr 20, 2018 at 11:52:47AM +0800, Jason Wang wrote: > > The biggest issue is that you let userspace poke at the > > device which is also allowed by the IOMMU to poke at > > kernel memory (needed for kernel driver to work). > > I don't quite get. The userspace driver could be built on top o

Re: [virtio-dev] Re: [RFC] vhost: introduce mdev based hardware vhost backend

2018-04-10 Thread Paolo Bonzini
On 10/04/2018 06:57, Tiwei Bie wrote: >> So you just move the abstraction layer from qemu to kernel, and you still >> need different drivers in kernel for different device interfaces of >> accelerators. This looks even more complex than leaving it in qemu. As you >> said, another idea is to impleme

RE: [virtio-dev] Re: [RFC] vhost: introduce mdev based hardware vhost backend

2018-04-10 Thread Liang, Cunming
; open.org; linux-ker...@vger.kernel.org; k...@vger.kernel.org; > virtualizat...@lists.linux-foundation.org; netdev@vger.kernel.org; Daly, Dan > ; Liang, Cunming ; Wang, > Zhihong ; Tan, Jianfeng ; > Wang, Xiao W > Subject: Re: [virtio-dev] Re: [RFC] vhost: introduce mdev based hardware &

Re: [virtio-dev] Re: [RFC] vhost: introduce mdev based hardware vhost backend

2018-04-10 Thread Michael S. Tsirkin
; > Zhihong ; Tan, Jianfeng ; > > Wang, Xiao W > > Subject: Re: [virtio-dev] Re: [RFC] vhost: introduce mdev based hardware > > vhost backend > > > > On 10/04/2018 06:57, Tiwei Bie wrote: > > >> So you just move the abstraction layer from qemu to kernel, and yo

RE: [virtio-dev] Re: [RFC] vhost: introduce mdev based hardware vhost backend

2018-04-10 Thread Liang, Cunming
; virtio-...@lists.oasis-open.org; linux-ker...@vger.kernel.org; > k...@vger.kernel.org; virtualizat...@lists.linux-foundation.org; > netdev@vger.kernel.org; Daly, Dan ; Wang, Zhihong > ; Tan, Jianfeng ; Wang, Xiao > W > Subject: Re: [virtio-dev] Re: [RFC] vhost: introduce mdev based hardw

RE: [virtio-dev] Re: [RFC] vhost: introduce mdev based hardware vhost backend

2018-04-10 Thread Tian, Kevin
> From: Liang, Cunming > Sent: Tuesday, April 10, 2018 10:24 PM > [...] > > > > As others said, we do not need to go overeboard. A couple of small > vendor- > > specific quirks in qemu isn't a big deal. > > It's quite challenge to identify it's small or not, there's no uniform metric. > > It's o

Re: [virtio-dev] Re: [RFC] vhost: introduce mdev based hardware vhost backend

2018-04-10 Thread Stefan Hajnoczi
On Tue, Apr 10, 2018 at 09:23:53AM +, Liang, Cunming wrote: > If QEMU is going to build a user space driver framework there, we're open > mind on that, even leveraging DPDK as the underlay library. Looking forward > to more others' comments from community. There is already an NVMe VFIO drive

Re: [virtio-dev] Re: [RFC] vhost: introduce mdev based hardware vhost backend

2018-04-10 Thread Jason Wang
@lists.oasis- open.org; linux-ker...@vger.kernel.org; k...@vger.kernel.org; virtualizat...@lists.linux-foundation.org; netdev@vger.kernel.org; Daly, Dan ; Liang, Cunming ; Wang, Zhihong ; Tan, Jianfeng ; Wang, Xiao W Subject: Re: [virtio-dev] Re: [RFC] vhost: introduce mdev based hardware vhost backend

Re: [virtio-dev] Re: [RFC] vhost: introduce mdev based hardware vhost backend

2018-04-10 Thread Jason Wang
-...@lists.oasis-open.org;linux-ker...@vger.kernel.org; k...@vger.kernel.org;virtualizat...@lists.linux-foundation.org; netdev@vger.kernel.org; Daly, Dan; Wang, Zhihong ; Tan, Jianfeng; Wang, Xiao W Subject: Re: [virtio-dev] Re: [RFC] vhost: introduce mdev based hardware vhost backend On Tue, Apr