Re: [PATCH] vdpa/mlx5: set_features should allow reset to zero

On Wed, Feb 24, 2021 at 04:26:43PM +0800, Jason Wang wrote:

    Basically on first guest access QEMU would tell kernel whether
    guest is using the legacy or the modern interface.
    E.g. virtio_pci_config_read/virtio_pci_config_write will call ioctl(ENABLE_LEGACY, 1)
    while virtio_pci_common_read will call ioctl(ENABLE_LEGACY, 0)


But this trick work only for PCI I think?

Thanks

ccw has a revision it can check. mmio does not have transitional devices
at all.

-- 
MST