• DPDK Ring and ivshmem
    • DPDK Ring
    • ivshmem
      • ivshmem使用示例

    DPDK Ring and ivshmem

    DPDK Ring

    DPDK Ring提供了一个FIFO无锁队列，支持丰富的队列操作，比如

    • Multi-consumer or single-consumer dequeue
    • Multi-producer or single-producer enqueue
    • Bulk dequeue - Dequeues the specified count of objects if successful; otherwise fails
    • Bulk enqueue - Enqueues the specified count of objects if successful; otherwise fails
    • Burst dequeue - Dequeue the maximum available objects if the specified count cannot be fulfilled
    • Burst enqueue - Enqueue the maximum available objects if the specified count cannot be fulfilled

    Ring和共享内存 - 图1

    ivshmem

    ivshmem则通过把内存映射成虚拟机PCI设备提供了虚拟机间(host-to-guest or guest-to-guest)共享内存的机制。

    Ring和共享内存 - 图2

    DPDK ivshmem:

    Ring和共享内存 - 图3

    ivshmem使用示例

    1. # on the host
    2. mount tmpfs /dev/shm -t tmpfs -osize=32m
    3. ivshmem_server -m 64 -p/tmp/nahanni &
    5. # start VM
    6. qemu-system-x86_64  -hda mg -L /pc-bios/ --smp 4 –chardev socket,path=/tmp/nahanni,id=nahanni-device ivshmem,chardev=nahanni,size=32m,msi=off -serial telnet:0.0.0.0:4000,server,nowait,nodelay-enable-kvm&
    8. # inside VM
    9. modprobe kvm_ivshmem
    10. cat/proc/devices | grep kvm_ivshmem
    11. mknod-mode=666 /dev/ivshmem c 245 0

    参考文档

    • DPDK Ring Library
    • DPDK IVSHMEM Library