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    macvtap: limit head length of skb allocated · 16a3fa28
    Jason Wang 提交于
    We currently use hdr_len as a hint of head length which is advertised by
    guest. But when guest advertise a very big value, it can lead to an 64K+
    allocating of kmalloc() which has a very high possibility of failure when host
    memory is fragmented or under heavy stress. The huge hdr_len also reduce the
    effect of zerocopy or even disable if a gso skb is linearized in guest.
    
    To solves those issues, this patch introduces an upper limit (PAGE_SIZE) of the
    head, which guarantees an order 0 allocation each time.
    
    Cc: Stefan Hajnoczi <stefanha@redhat.com>
    Cc: Michael S. Tsirkin <mst@redhat.com>
    Signed-off-by: NJason Wang <jasowang@redhat.com>
    Signed-off-by: NDavid S. Miller <davem@davemloft.net>
    16a3fa28
macvtap.c 29.2 KB