The goal of these patches are to add support to a variety of virtio and vhost devices for the VIRTIO_F_NOTIFICATION_DATA transport feature. This feature indicates that a driver will pass extra data (instead of just a virtqueue's index) when notifying the corresponding device.
The data passed in by the driver when this feature is enabled varies in format depending on if the device is using a split or packed virtqueue layout: Split VQ - Upper 16 bits: shadow_avail_idx - Lower 16 bits: virtqueue index Packed VQ - Upper 16 bits: 1-bit wrap counter & 15-bit shadow_avail_idx - Lower 16 bits: virtqueue index Also, due to the limitations of ioeventfd not being able to carry the extra provided by the driver, ioeventfd is left disabled for any devices using this feature. A significant aspect of this effort has been to maintain compatibility across different backends. As such, the feature is offered by backend devices only when supported, with fallback mechanisms where backend support is absent. Jonah Palmer (8): virtio/virtio-pci: Handle extra notification data virtio-pci: Lock ioeventfd state with VIRTIO_F_NOTIFICATION_DATA virtio-mmio: Handle extra notification data virtio-mmio: Lock ioeventfd state with VIRTIO_F_NOTIFICATION_DATA virtio-ccw: Handle extra notification data virtio-ccw: Lock ioeventfd state with VIRTIO_F_NOTIFICATION_DATA vhost/vhost-user: Add VIRTIO_F_NOTIFICATION_DATA to vhost feature bits virtio: Add VIRTIO_F_NOTIFICATION_DATA property definition hw/block/vhost-user-blk.c | 1 + hw/net/vhost_net.c | 2 ++ hw/s390x/s390-virtio-ccw.c | 16 ++++++++++++---- hw/s390x/virtio-ccw.c | 6 ++++-- hw/scsi/vhost-scsi.c | 1 + hw/scsi/vhost-user-scsi.c | 1 + hw/virtio/vhost-user-fs.c | 2 +- hw/virtio/vhost-user-vsock.c | 1 + hw/virtio/virtio-mmio.c | 15 +++++++++++---- hw/virtio/virtio-pci.c | 16 +++++++++++----- hw/virtio/virtio.c | 18 ++++++++++++++++++ include/hw/virtio/virtio.h | 5 ++++- net/vhost-vdpa.c | 1 + 13 files changed, 68 insertions(+), 17 deletions(-) -- 2.39.3
