qmp: decode feature & status bits in virtio-status

qmp: decode feature & status bits in virtio-status

Display feature names instead of bitmaps for host, guest, and
backend for VirtIODevices.

Display status names instead of bitmaps for VirtIODevices.

Display feature names instead of bitmaps for backend, protocol,
acked, and features (hdev->features) for vhost devices.

Decode features according to device ID. Decode statuses
according to configuration status bitmap (config_status_map).
Decode vhost user protocol features according to vhost user
protocol bitmap (vhost_user_protocol_map).

Transport features are on the first line. Undecoded bits (if
any) are stored in a separate field.

[Jonah: Several changes made to this patch from prev. version (v14):
 - Moved all device features mappings to hw/virtio/virtio.c
 - Renamed device features mappings (less generic)
 - Generalized @FEATURE_ENTRY macro for all device mappings
 - Virtio device feature map definitions include descriptions of
   feature bits
 - Moved @VHOST_USER_F_PROTOCOL_FEATURES feature bit from transport
   feature map to vhost-user-supported device feature mappings
   (blk, fs, i2c, rng, net, gpu, input, scsi, vsock)
 - New feature bit added for virtio-vsock: @VIRTIO_VSOCK_F_SEQPACKET
 - New feature bit added for virtio-iommu: @VIRTIO_IOMMU_F_BYPASS_CONFIG
 - New feature bit added for virtio-mem: @VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE
 - New virtio transport feature bit added: @VIRTIO_F_IN_ORDER
 - Added device feature map definition for virtio-rng
]

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jonah Palmer <jonah.palmer@oracle.com>
Message-Id: <1660220684-24909-4-git-send-email-jonah.palmer@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>