Hello everyone, This RFC implements packed ring support in virtio driver. Some functional tests have been done with Jason's packed ring implementation in vhost (RFC v5): https://lwn.net/Articles/755862/ Both of ping and netperf worked as expected. TODO: - Refinements (for code and commit log); - More tests and bug fixes if any; - Send the formal patch set; RFC v5 -> RFC v6: - Avoid tracking addr/len/flags when DMA API isn't used (MST/Jason); - Define wrap counter as bool (Jason); - Use ALIGN() in vring_init_packed() (Jason); - Avoid using pointer to track `next` in detach_buf_packed() (Jason); - Add comments for barriers (Jason); - Don't enable RING_PACKED on ccw for now (noticed by Jason); - Refine the memory barrier in virtqueue_poll(); - Add a missing memory barrier in virtqueue_enable_cb_delayed_packed(); - Remove the hacks in virtqueue_enable_cb_prepare_packed(); RFC v4 -> RFC v5: - Save DMA addr, etc in desc state (Jason); - Track used wrap counter; RFC v3 -> RFC v4: - Make ID allocation support out-of-order (Jason); - Various fixes for EVENT_IDX support; RFC v2 -> RFC v3: - Split into small patches (Jason); - Add helper virtqueue_use_indirect() (Jason); - Just set id for the last descriptor of a list (Jason); - Calculate the prev in virtqueue_add_packed() (Jason); - Fix/improve desc suppression code (Jason/MST); - Refine the code layout for XXX_split/packed and wrappers (MST); - Fix the comments and API in uapi (MST); - Remove the BUG_ON() for indirect (Jason); - Some other refinements and bug fixes; RFC v1 -> RFC v2: - Add indirect descriptor support - compile test only; - Add event suppression supprt - compile test only; - Move vring_packed_init() out of uapi (Jason, MST); - Merge two loops into one in virtqueue_add_packed() (Jason); - Split vring_unmap_one() for packed ring and split ring (Jason); - Avoid using '%' operator (Jason); - Rename free_head -> next_avail_idx (Jason); - Add comments for virtio_wmb() in virtqueue_add_packed() (Jason); - Some other refinements and bug fixes; Thanks! Tiwei Bie (5): virtio: add packed ring definitions virtio_ring: support creating packed ring virtio_ring: add packed ring support virtio_ring: add event idx support in packed ring virtio_ring: enable packed ring drivers/s390/virtio/virtio_ccw.c | 8 + drivers/virtio/virtio_ring.c | 1361 ++++++++++++++++++++++------ include/linux/virtio_ring.h | 8 +- include/uapi/linux/virtio_config.h | 5 +- include/uapi/linux/virtio_ring.h | 36 + 5 files changed, 1141 insertions(+), 277 deletions(-) -- 2.17.0 _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
