search for: virtio_nvme

Hi all, These 2 patches added virtio-nvme to kernel and qemu, basically modified from virtio-blk and nvme code. As title said, request for your comments. Play it in Qemu with: -drive file=disk.img,format=raw,if=none,id=D22 \ -device virtio-nvme-pci,drive=D22,serial=1234,num_queues=4 The goal is to have a full NVMe stack from VM guest(virtio-nvme) to host(vhost_nvme) to LIO NVMe-over-fabrics

Hi all, These 2 patches added virtio-nvme to kernel and qemu, basically modified from virtio-blk and nvme code. As title said, request for your comments. Play it in Qemu with: -drive file=disk.img,format=raw,if=none,id=D22 \ -device virtio-nvme-pci,drive=D22,serial=1234,num_queues=4 The goal is to have a full NVMe stack from VM guest(virtio-nvme) to host(vhost_nvme) to LIO NVMe-over-fabrics

...or you think the > performance will be significantly better than virtio-blk/virtio-scsi? It simply passes through NVMe commands. Right now performance is poor. Performance tunning is on my todo list. It should be as good as virtio-blk/virtio-scsi. > > At first glance it seems like the virtio_nvme guest driver is just > another block driver like virtio_blk, so I'm not clear why a > virtio-nvme device makes sense. I think the future "LIO NVMe target" only speaks NVMe protocol. Nick(CCed), could you correct me if I'm wrong? For SCSI stack, we have: virtio-scsi(guest)...

...or you think the > performance will be significantly better than virtio-blk/virtio-scsi? It simply passes through NVMe commands. Right now performance is poor. Performance tunning is on my todo list. It should be as good as virtio-blk/virtio-scsi. > > At first glance it seems like the virtio_nvme guest driver is just > another block driver like virtio_blk, so I'm not clear why a > virtio-nvme device makes sense. I think the future "LIO NVMe target" only speaks NVMe protocol. Nick(CCed), could you correct me if I'm wrong? For SCSI stack, we have: virtio-scsi(guest)...

...that you want to pass through, or you think the > >> performance will be significantly better than virtio-blk/virtio-scsi? > > > > It simply passes through NVMe commands. > > I understand that. My question is why the guest needs to send NVMe commands? > > If the virtio_nvme.ko guest driver only sends read/write/flush then > there's no advantage over virtio-blk. > > There must be something you are trying to achieve which is not > possible with virtio-blk or virtio-scsi. What is that? I actually learned from your virtio-scsi work. http://www.linux-kvm...

...that you want to pass through, or you think the > >> performance will be significantly better than virtio-blk/virtio-scsi? > > > > It simply passes through NVMe commands. > > I understand that. My question is why the guest needs to send NVMe commands? > > If the virtio_nvme.ko guest driver only sends read/write/flush then > there's no advantage over virtio-blk. > > There must be something you are trying to achieve which is not > possible with virtio-blk or virtio-scsi. What is that? I actually learned from your virtio-scsi work. http://www.linux-kvm...

...hese 2 patches added virtio-nvme to kernel and qemu, > > > > basically modified from virtio-blk and nvme code. > > > > > > > > As title said, request for your comments. > > <SNIP> > > > > > > > At first glance it seems like the virtio_nvme guest driver is just > > > another block driver like virtio_blk, so I'm not clear why a > > > virtio-nvme device makes sense. > > > > I think the future "LIO NVMe target" only speaks NVMe protocol. > > > > Nick(CCed), could you correct me if...

...hese 2 patches added virtio-nvme to kernel and qemu, > > > > basically modified from virtio-blk and nvme code. > > > > > > > > As title said, request for your comments. > > <SNIP> > > > > > > > At first glance it seems like the virtio_nvme guest driver is just > > > another block driver like virtio_blk, so I'm not clear why a > > > virtio-nvme device makes sense. > > > > I think the future "LIO NVMe target" only speaks NVMe protocol. > > > > Nick(CCed), could you correct me if...

...; > These 2 patches added virtio-nvme to kernel and qemu, >> > > basically modified from virtio-blk and nvme code. >> > > >> > > As title said, request for your comments. > > <SNIP> > >> > >> > At first glance it seems like the virtio_nvme guest driver is just >> > another block driver like virtio_blk, so I'm not clear why a >> > virtio-nvme device makes sense. >> >> I think the future "LIO NVMe target" only speaks NVMe protocol. >> >> Nick(CCed), could you correct me if I'm...

...; > These 2 patches added virtio-nvme to kernel and qemu, >> > > basically modified from virtio-blk and nvme code. >> > > >> > > As title said, request for your comments. > > <SNIP> > >> > >> > At first glance it seems like the virtio_nvme guest driver is just >> > another block driver like virtio_blk, so I'm not clear why a >> > virtio-nvme device makes sense. >> >> I think the future "LIO NVMe target" only speaks NVMe protocol. >> >> Nick(CCed), could you correct me if I'm...

...; to host(vhost_nvme) to LIO NVMe-over-fabrics target. Why is a virtio-nvme guest device needed? I guess there must either be NVMe-only features that you want to pass through, or you think the performance will be significantly better than virtio-blk/virtio-scsi? At first glance it seems like the virtio_nvme guest driver is just another block driver like virtio_blk, so I'm not clear why a virtio-nvme device makes sense. > Now there are lots of duplicated code with linux/nvme-core.c and qemu/nvme.c. > The ideal result is to have a multi level NVMe stack(similar as SCSI). > So we can re-use...

...ther >> be NVMe-only features that you want to pass through, or you think the >> performance will be significantly better than virtio-blk/virtio-scsi? > > It simply passes through NVMe commands. I understand that. My question is why the guest needs to send NVMe commands? If the virtio_nvme.ko guest driver only sends read/write/flush then there's no advantage over virtio-blk. There must be something you are trying to achieve which is not possible with virtio-blk or virtio-scsi. What is that? Stefan

...ough, or you think the >> >> performance will be significantly better than virtio-blk/virtio-scsi? >> > >> > It simply passes through NVMe commands. >> >> I understand that. My question is why the guest needs to send NVMe commands? >> >> If the virtio_nvme.ko guest driver only sends read/write/flush then >> there's no advantage over virtio-blk. >> >> There must be something you are trying to achieve which is not >> possible with virtio-blk or virtio-scsi. What is that? > > I actually learned from your virtio-scsi wo...

...el and qemu, > > > > > basically modified from virtio-blk and nvme code. > > > > > > > > > > As title said, request for your comments. > > > > <SNIP> > > > > > > > > > > At first glance it seems like the virtio_nvme guest driver is just > > > > another block driver like virtio_blk, so I'm not clear why a > > > > virtio-nvme device makes sense. > > > > > > I think the future "LIO NVMe target" only speaks NVMe protocol. > > > > > > Nick(...

...t kernel.org> wrote: > > > These 2 patches added virtio-nvme to kernel and qemu, > > > basically modified from virtio-blk and nvme code. > > > > > > As title said, request for your comments. <SNIP> > > > > At first glance it seems like the virtio_nvme guest driver is just > > another block driver like virtio_blk, so I'm not clear why a > > virtio-nvme device makes sense. > > I think the future "LIO NVMe target" only speaks NVMe protocol. > > Nick(CCed), could you correct me if I'm wrong? > > For...

...t; basically modified from virtio-blk and nvme code. > > > > > > > > > > > > As title said, request for your comments. > > > > > > <SNIP> > > > > > > > > > > > > > At first glance it seems like the virtio_nvme guest driver is just > > > > > another block driver like virtio_blk, so I'm not clear why a > > > > > virtio-nvme device makes sense. > > > > > > > > I think the future "LIO NVMe target" only speaks NVMe protocol. > > > &...

...t; basically modified from virtio-blk and nvme code. > > > > > > > > > > > > As title said, request for your comments. > > > > > > <SNIP> > > > > > > > > > > > > > At first glance it seems like the virtio_nvme guest driver is just > > > > > another block driver like virtio_blk, so I'm not clear why a > > > > > virtio-nvme device makes sense. > > > > > > > > I think the future "LIO NVMe target" only speaks NVMe protocol. > > > &...