search for: io_req

Hi, This is the first attempt to add a new qemu nvme backend using in-kernel nvme target. Most code are ported from qemu-nvme and also borrow code from Hannes Reinecke's rts-megasas. It's similar as vhost-scsi, but doesn't use virtio. The advantage is guest can run unmodified NVMe driver. So guest can be any OS that has a NVMe driver. The goal is to get as good performance as

Hi, This is the first attempt to add a new qemu nvme backend using in-kernel nvme target. Most code are ported from qemu-nvme and also borrow code from Hannes Reinecke's rts-megasas. It's similar as vhost-scsi, but doesn't use virtio. The advantage is guest can run unmodified NVMe driver. So guest can be any OS that has a NVMe driver. The goal is to get as good performance as

...NvmeSQueue *sq; hwaddr addr; + nvme_update_cq_head(cq); + if (nvme_cq_full(cq)) { break; } @@ -350,6 +361,8 @@ static void nvme_init_sq(NvmeSQueue *sq, NvmeCtrl *n, uint64_t dma_addr, QTAILQ_INSERT_TAIL(&(sq->req_list), &sq->io_req[i], entry); } sq->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, nvme_process_sq, sq); + sq->db_addr = 0; + sq->eventidx_addr = 0; assert(n->cq[cqid]); cq = n->cq[cqid]; @@ -430,6 +443,8 @@ static void nvme_init_cq(NvmeCQueue *cq, NvmeCtrl *n, uint64_t dma_addr,...

Hi Rob & Mihai, I wrote vhost-nvme patches on top of Christoph's NVMe target. vhost-nvme still uses mmio. So the guest OS can run unmodified NVMe driver. But the tests I have done didn't show competitive performance compared to virtio-blk/virtio-scsi. The bottleneck is in mmio. Your nvme vendor extension patches reduces greatly the number of MMIO writes. So I'd like to push it

Hi Rob & Mihai, I wrote vhost-nvme patches on top of Christoph's NVMe target. vhost-nvme still uses mmio. So the guest OS can run unmodified NVMe driver. But the tests I have done didn't show competitive performance compared to virtio-blk/virtio-scsi. The bottleneck is in mmio. Your nvme vendor extension patches reduces greatly the number of MMIO writes. So I'd like to push it