From: "Edgar E. Iglesias" <[email protected]> This adds virtio-msg, a new virtio transport. Virtio-msg works by exchanging messages over a bus and doesn't rely on trapping and emulation making it a good fit for a number of applications such as AMP, real-time and safety applications.
Together with the new transport, this series adds a PCI device that implements an AMP setup much like it could look if two SoC's would use virtio-msg across a PCI link. Current gaps and limitations: No support for SHM regions yet. Temporarily uses PCI Vendor Xilinx / Device 0x9039. The virtio-msg draft spec: https://github.com/Linaro/virtio-msg-spec/ QEMU with these patches: https://github.com/edgarigl/qemu/tree/edgar/virtio-msg-rfc Linux with virtio-msg support: https://github.com/edgarigl/linux/tree/edgari/virtio-msg-6.17 To try it, first build Linux with the following enabled: CONFIG_VIRTIO_MSG=y CONFIG_VIRTIO_MSG_AMP=y CONFIG_VIRTIO_MSG_AMP_PCI=y Boot linux on QEMU with a virtio-msg-amp-pci device, in this example with a virtio-net device attached to it: -device virtio-msg-amp-pci -device virtio-net-device,netdev=n0 -netdev user,id=n0 If you're running on a QEMU machine that has virtio-mmio enabled, e.g ARM virt, you'll need to specify the virtio-bus for the device, otherwise QEMU will connect it to virtio-mmio. For ARM virt machines: -device virtio-msg-amp-pci -device virtio-net-device,netdev=n0,bus=/gpex-pcihost/pcie.0/virtio-msg-amp-pci/fifo0/virtio-msg/bus0/virtio-msg-dev -netdev user,id=n0 Cheers, Edgar ChangeLog: v1 -> v2: * Clamp get_features block count. * Remove virtio notify_queue in favor of per queue vectors. * Enable NOTIFICATION_DATA. * Drop unpexpected responses rather than assert. * Fix msg handler bounds check. * Guard handlers against missing devices. * Respond to bus pings. * Add BUS_GET_DEVICES. * Fix use of uninitialized var in virtio_msg_reset_hold. * Fix EVENT_CONFIG message length. * amp-pci: Fix fifo offset computation. * amp-pci: Don't notify when dropping messages. * Document virtio_queue_get_rings. * Add virtio-msg-amp-pci.rst to index.rst. Edgar E. Iglesias (4): virtio: Add virtio_queue_get_rings virtio: Add the virtio-msg transport hw/misc: Add generic virtio-msg AMP PCI device docs: Describe virtio-msg-amp-pci docs/system/devices/virtio/index.rst | 1 + .../devices/virtio/virtio-msg-amp-pci.rst | 92 ++ hw/misc/Kconfig | 7 + hw/misc/meson.build | 1 + hw/misc/virtio-msg-amp-pci.c | 361 +++++++ hw/virtio/Kconfig | 4 + hw/virtio/meson.build | 5 + hw/virtio/virtio-msg-bus.c | 89 ++ hw/virtio/virtio-msg.c | 986 ++++++++++++++++++ hw/virtio/virtio.c | 16 + include/hw/virtio/spsc_queue.h | 213 ++++ include/hw/virtio/virtio-msg-bus.h | 95 ++ include/hw/virtio/virtio-msg-prot.h | 949 +++++++++++++++++ include/hw/virtio/virtio-msg.h | 56 + include/hw/virtio/virtio.h | 14 + 15 files changed, 2889 insertions(+) create mode 100644 docs/system/devices/virtio/virtio-msg-amp-pci.rst create mode 100644 hw/misc/virtio-msg-amp-pci.c create mode 100644 hw/virtio/virtio-msg-bus.c create mode 100644 hw/virtio/virtio-msg.c create mode 100644 include/hw/virtio/spsc_queue.h create mode 100644 include/hw/virtio/virtio-msg-bus.h create mode 100644 include/hw/virtio/virtio-msg-prot.h create mode 100644 include/hw/virtio/virtio-msg.h -- 2.43.0
