vDPA network devices allow high-performance networking in a virtual machine by providing a wire-speed data path. These devices require a vendor-specific host driver but the data path follows the virtio specification.
The support for vDPA devices was recently added to qemu. This allows libvirt to support these devices. This patchset requires that the device is configured on the host with the appropriate vendor-specific driver. This will create a chardev on the host at e.g. /dev/vhost-vdpa-0. That chardev path can then be used to define a new interface with type=3D'vdpa'. Note that in order for hot-unplug to work properly, you may need to apply a qemu patch[1] for now. Without the patch, qemu will not close the fd properly and any subsequent attempts to use the vdpa chardev will fail like this: virsh # attach-device guest1 vdpa.xml error: Failed to attach device from vdpa.xml error: Unable to open '/dev/vhost-vdpa-0' for vdpa device: Device or reso= urce busy [1] https://lists.nongnu.org/archive/html/qemu-devel/2020-09/msg06374.html Changes in v5: - rebased to latest master - fixed a case where qemuDomainObjExitMonitor() was not called on an error p= ath - Improved the nodedev xml. It now includes the path to the chardev in /dev - also updated the nodedev xml schema - added sample nodedev-dumpxml output to the commit message of patch #6 Jonathon Jongsma (6): conf: Add support for vDPA network devices qemu: add vhost-vdpa capability qemu: add vdpa support qemu: add monitor functions for handling file descriptors qemu: support hotplug of vdpa devices Include vdpa devices in node device list docs/formatdomain.rst | 24 +++ docs/formatnode.html.in | 9 + docs/schemas/domaincommon.rng | 15 ++ docs/schemas/nodedev.rng | 10 + include/libvirt/libvirt-nodedev.h | 1 + src/conf/domain_conf.c | 31 ++++ src/conf/domain_conf.h | 4 + src/conf/netdev_bandwidth_conf.c | 1 + src/conf/node_device_conf.c | 14 ++ src/conf/node_device_conf.h | 11 +- src/conf/virnodedeviceobj.c | 4 +- src/libxl/libxl_conf.c | 1 + src/libxl/xen_common.c | 1 + src/lxc/lxc_controller.c | 1 + src/lxc/lxc_driver.c | 3 + src/lxc/lxc_process.c | 1 + src/node_device/node_device_udev.c | 53 ++++++ src/qemu/qemu_capabilities.c | 2 + src/qemu/qemu_capabilities.h | 1 + src/qemu/qemu_command.c | 36 +++- src/qemu/qemu_command.h | 3 +- src/qemu/qemu_domain.c | 6 +- src/qemu/qemu_hotplug.c | 75 +++++++- src/qemu/qemu_interface.c | 25 +++ src/qemu/qemu_interface.h | 2 + src/qemu/qemu_migration.c | 10 +- src/qemu/qemu_monitor.c | 93 ++++++++++ src/qemu/qemu_monitor.h | 41 +++++ src/qemu/qemu_monitor_json.c | 173 ++++++++++++++++++ src/qemu/qemu_monitor_json.h | 12 ++ src/qemu/qemu_process.c | 2 + src/qemu/qemu_validate.c | 15 ++ src/vmx/vmx.c | 1 + .../caps_5.1.0.x86_64.xml | 1 + .../caps_5.2.0.x86_64.xml | 1 + tests/qemuhotplugmock.c | 9 + tests/qemuhotplugtest.c | 16 ++ .../qemuhotplug-interface-vdpa.xml | 4 + .../qemuhotplug-base-live+interface-vdpa.xml | 57 ++++++ .../net-vdpa.x86_64-latest.args | 38 ++++ tests/qemuxml2argvdata/net-vdpa.xml | 28 +++ tests/qemuxml2argvmock.c | 11 +- tests/qemuxml2argvtest.c | 1 + tests/qemuxml2xmloutdata/net-vdpa.xml | 34 ++++ tests/qemuxml2xmltest.c | 1 + tools/virsh-domain.c | 1 + tools/virsh-nodedev.c | 3 + 47 files changed, 870 insertions(+), 16 deletions(-) create mode 100644 tests/qemuhotplugtestdevices/qemuhotplug-interface-vdpa.x= ml create mode 100644 tests/qemuhotplugtestdomains/qemuhotplug-base-live+interf= ace-vdpa.xml create mode 100644 tests/qemuxml2argvdata/net-vdpa.x86_64-latest.args create mode 100644 tests/qemuxml2argvdata/net-vdpa.xml create mode 100644 tests/qemuxml2xmloutdata/net-vdpa.xml --=20 2.26.2