• Ian Campbell's avatar
    xen network backend driver · f942dc25
    Ian Campbell authored
    netback is the host side counterpart to the frontend driver in
    drivers/net/xen-netfront.c. The PV protocol is also implemented by
    frontend drivers in other OSes too, such as the BSDs and even Windows.
    
    The patch is based on the driver from the xen.git pvops kernel tree but
    has been put through the checkpatch.pl wringer plus several manual
    cleanup passes and review iterations. The driver has been moved from
    drivers/xen/netback to drivers/net/xen-netback.
    
    One major change from xen.git is that the guest transmit path (i.e. what
    looks like receive to netback) has been significantly reworked to remove
    the dependency on the out of tree PageForeign page flag (a core kernel
    patch which enables a per page destructor callback on the final
    put_page). This page flag was used in order to implement a grant map
    based transmit path (where guest pages are mapped directly into SKB
    frags). Instead this version of netback uses grant copy operations into
    regular memory belonging to the backend domain. Reinstating the grant
    map functionality is something which I would like to revisit in the
    future.
    
    Note that this driver depends on 2e820f58 "xen/irq: implement
    bind_interdomain_evtchn_to_irqhandler for backend drivers" which is in
    linux next via the "xen-two" tree and is intended for the 2.6.39 merge
    window:
            git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git
    
     stable/backends
    this branch has only that single commit since 2.6.38-rc2 and is safe for
    cross merging into the net branch.
    Signed-off-by: default avatarIan Campbell <ian.campbell@citrix.com>
    Reviewed-by: default avatarBen Hutchings <bhutchings@solarflare.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    f942dc25