Control virtqueue is used by networking device for accepting various commands from the driver. It's a must to support advanced configurations.
Rx filtering event is issues by qemu when device's MAC address changed once and the previous one has not been queried by external agents. Shadow VirtQueue (SVQ) already makes possible tracking the state of virtqueues, effectively intercepting them so qemu can track what regions of memory are dirty because device action and needs migration. However, this does not solve networking device state seen by the driver because CVQ messages, like changes on MAC addresses from the driver. This series uses SVQ infraestructure to intercept networking control messages used by the device. This way, qemu is able to update VirtIONet device model and react to them. In particular, this series enables rx filter change notification. This is a pre-requisite to achieve net vdpa device with CVQ live migration. It's a stripped down version of [1], with error paths checked and no migration enabled. First patch solves a memory leak if the device is able to trick qemu to think it has returned more buffers than svq size. This should not be possible, but we're a bit safer this way. Next nine patches reorder and clean code base so its easier to apply later ones. No functional change should be noticed from these changes. Patches from 11 to 16 enable SVQ API to make other parts of qemu to interact with it. In particular, they will be used by vhost-vdpa net to handle CVQ messages. Patches 17 to 19 enable the update of the virtio-net device model for each CVQ message acknoledged by the device. Last patches enable x-svq parameter, forbidding device migration since it is not restored in the destination's vdpa device yet. This will be added in later series, using this work. Comments are welcome. [1] https://patchwork.kernel.org/project/qemu-devel/cover/20220706184008.1649478-1-epere...@redhat.com/ Eugenio Pérez (22): vhost: Return earlier if used buffers overrun vhost: move descriptor translation to vhost_svq_vring_write_descs vdpa: Clean vhost_vdpa_dev_start(dev, false) virtio-net: Expose ctrl virtqueue logic vhost: Decouple vhost_svq_add_split from VirtQueueElement vhost: Reorder vhost_svq_last_desc_of_chain vhost: Add SVQElement vhost: Move last chain id to SVQ element vhost: Add opaque member to SVQElement vdpa: Small rename of error labels vhost: add vhost_svq_push_elem vhost: Add vhost_svq_inject vhost: add vhost_svq_poll vhost: Add custom used buffer callback vhost: Add svq avail_handler callback vhost: add detach SVQ operation vdpa: Export vhost_vdpa_dma_map and unmap calls vdpa: manual forward CVQ buffers vdpa: Buffer CVQ support on shadow virtqueue vdpa: Extract get features part from vhost_vdpa_get_max_queue_pairs vdpa: Add device migration blocker vdpa: Add x-svq to NetdevVhostVDPAOptions qapi/net.json | 9 +- hw/virtio/vhost-shadow-virtqueue.h | 64 +++- include/hw/virtio/vhost-vdpa.h | 8 + include/hw/virtio/virtio-net.h | 4 + hw/net/virtio-net.c | 84 ++--- hw/virtio/vhost-shadow-virtqueue.c | 287 +++++++++++++---- hw/virtio/vhost-vdpa.c | 63 ++-- net/vhost-vdpa.c | 473 ++++++++++++++++++++++++++++- 8 files changed, 855 insertions(+), 137 deletions(-) -- 2.31.1