• Tiwei Bie's avatar
    virtio: support VIRTIO_F_ORDER_PLATFORM · 45383fb0
    Tiwei Bie authored
    This patch introduces the support for VIRTIO_F_ORDER_PLATFORM.
    If this feature is negotiated, the driver must use the barriers
    suitable for hardware devices. Otherwise, the device and driver
    are assumed to be implemented in software, that is they can be
    assumed to run on identical CPUs in an SMP configuration. Thus
    a weaker form of memory barriers is sufficient to yield better
    performance.
    
    It is recommended that an add-in card based PCI device offers
    this feature for portability. The device will fail to operate
    further or will operate in a slower emulation mode if this
    feature is offered but not accepted.
    Signed-off-by: default avatarTiwei Bie <tiwei.bie@intel.com>
    Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
    45383fb0
virtio_ring.c 60.6 KB