On Thu, May 18, 2023 at 08:47:22AM +0800, zhenwei pi wrote: > On 5/17/23 18:39, Michael S. Tsirkin wrote: > > On Wed, May 17, 2023 at 04:35:55PM +0800, zhenwei pi wrote: > > > > > > > > > On 5/17/23 15:46, Christoph Hellwig wrote: > > > > On Wed, May 17, 2023 at 03:43:03PM +0800, zhenwei pi wrote: > > > > > I have a plan to introduce 'Virtio Over Fabrics'(TCP&RDMA) as Virtio > > > > > transport, as mentioned in cover letter of this series: > > > > > 3 weeks ago, I posted a proposal 'Virtio Over Fabrics': > > > > > https://lists.oasis-open.org/archives/virtio-comment/202304/msg00442.html > > > > > > > > Just don't do it. Please define your own protocols over RDMA or TCP > > > > for exactly the operations you need (for many they will already exist) > > > > instead of piggyg backing on virtio and making everyone else pay the > > > > price. > > > > > > > > > > Hi > > > > > > 1, `virtqueue_add_inbuf` in current version: > > > static inline int virtqueue_add_inbuf(struct virtqueue *vq, > > > struct scatterlist *sg, > > > unsigned int num, > > > void *data, > > > gfp_t gfp) > > > { > > > if (likely(!vq->abstract)) > > > return vring_virtqueue_add_sgs(vq, &sg, num, 0, 1, data, > > > NULL, gfp); > > > > > > return vq->add_sgs(vq, &sg, num, 0, 1, data, NULL, gfp); > > > } > > > > > > And disassemble 'virtinput_queue_evtbuf': > > > static void virtinput_queue_evtbuf(struct virtio_input *vi, > > > struct virtio_input_event *evtbuf) > > > { > > > struct scatterlist sg[1]; > > > > > > sg_init_one(sg, evtbuf, sizeof(*evtbuf)); > > > virtqueue_add_inbuf(vi->evt, sg, 1, evtbuf, GFP_ATOMIC); > > > } > > > > > > I notice that two instructions are newly added for vring like: > > > 24d: 80 78 35 00 cmpb $0x0,0x35(%rax) > > > 251: 75 3f jne 292 > > > > > > Is it an expensive price... > > > > Can we somehow only override the kick method? > > Then take the ring and send it over ... > > > > Could you please take a look at this code? > https://github.com/pizhenwei/linux/blob/virtio-of-github/drivers/virtio/virtio_fabrics.c#LL861C13-L861C23 what am I looking at here? Looks like at least vof_handle_vq duplicates some code from vringh. But besides that yes, that's the idea. > > > > > 2, Storage/FS specific remote protocol is quite popular, otherwise I'm not > > > familiar with other device protocols. For example, I need a remote crypto > > > device to accelerate HTTPS ... With Virtio Over Fabrics, I have a chance to > > > attach a virtio-crypto device to do this work. > > > > > > -- > > > zhenwei pi > > > > -- > zhenwei pi _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
