Hello Chenbo, On Thu, Jan 14, 2021 at 7:19 AM Chenbo Xia <chenbo....@intel.com> wrote: > > This series enables DPDK to be an alternative I/O device emulation library of > building virtualized devices in separate processes outside QEMU. It introduces > a new library for device emulation (librte_vfio_user). > > *librte_vfio_user* library is an implementation of VFIO-over-socket[1] (also > known as vfio-user) which is a protocol that allows a device to be virtualized > in a separate process outside of QEMU. > > Background & Motivation > ----------------------- > The disaggregated/multi-process QEMU is using VFIO-over-socket/vfio-user > as the main transport mechanism to disaggregate IO services from QEMU[2]. > Vfio-user essentially implements the VFIO device model presented to the > user process by a set of messages over a unix-domain socket. The main > difference between application using vfio-user and application using vfio > kernel module is that device manipulation is based on socket messages for > vfio-user but system calls for vfio kernel module. The vfio-user devices > consist of a generic VFIO device type, living in QEMU, which is called the > client[3], and the core device implementation (emulated device), living > outside of QEMU, which is called the server. With emulated devices removed > from QEMU enabled by vfio-user implementation, other places should be > introduced to accommodate virtualized/emulated device. This series introduces > vfio-user support in DPDK to enable DPDK as one of the living places for > emulated device except QEMU. > > This series introduce the server and client implementation of vfio-user > protocol. > The server plays the role as emulated devices and the client is the device > consumer. With this implementation, DPDK will be enabled to be both device > provider and consumer. > > Design overview > --------------- > > +--------------+ +--------------+ > | +----------+ | | +----------+ | > | | Generic | | | | Emulated | | > | | vfio-dev | | | | device | | > | +----------+ | | +----|-----+ | > | +----------+ | | +----|-----+ | > | | vfio-user| | | | vfio-user| | > | | client | |<--->| | server | | > | +----------+ | | +----------+ | > | QEMU/DPDK | | DPDK | > +--------------+ +--------------+ > > - Generic vfio-dev. > It is the generic vfio framework in vfio applications like QEMU or DPDK. > Applications can keep the most of vfio device management and plug in a > vfio-user device type. Note that in current implementation, we have not > yet integrated client vfio-user into kernel vfio in DPDK but it is viable > and good to do so. > > - vfio-user client. > For DPDK, it is part of librte_vfio_user implementation to provide ways to > manipulate a vfio-user based emulated devices. This manipulation is very > similar with kernel vfio (i.e., syscalls like ioctl, mmap and pread/pwrite). > It is a base for vfio-user device consumer. > > - vfio-user server. > It is server part of librte_vfio_user. It provides ways to emulate your own > device. A device provider could only care about device layout that VFIO > defines but does not need to know how it communicates with vfio-user client. > > - Emulated device. > It is emulated device of any type (e.g., network, crypto and etc.). > > References > ---------- > [1]: > https://patchew.org/QEMU/20201130161229.23164-1-thanos.maka...@nutanix.com/ > [2]: https://wiki.qemu.org/Features/MultiProcessQEMU > [3]: https://github.com/oracle/qemu/tree/vfio-user-v0.2 > > ---------------------------------- > v2: > - Clean up non-static inline function (Stephen) > - Naturally pack vfio-user message payload and header (Stephen) > - Make function definiton align with coding style (Beilei) > - Clean up duplicate code in vfio-user server APIs (Beilei) > - Fix some typos
GHA (called by the robot) caught various issues: - doc: https://github.com/ovsrobot/dpdk/runs/1700373705?check_suite_focus=true#step:14:3407 - clang: https://github.com/ovsrobot/dpdk/runs/1700373722?check_suite_focus=true#step:14:1050 - i386: https://github.com/ovsrobot/dpdk/runs/1700373747?check_suite_focus=true#step:14:2607 - aarch64: https://github.com/ovsrobot/dpdk/runs/1700373764?check_suite_focus=true#step:14:2848 and https://github.com/ovsrobot/dpdk/runs/1700373770?check_suite_focus=true#step:14:2880 -- David Marchand
