• MMIO exits are more expensive in KVM or Xen than in QEMU because they 
    involve, at least, privilege transitions.  However, MMIO write 
    operations can be effectively batched if those writes do not have side 
    effects.
    
    Good examples of this include VGA pixel operations when in a planar 
    mode.  As it turns out, we can get a nice boost in other areas too.  
    Laurent mentioned a 9.7% performance boost in iperf with the coalesced 
    MMIO changes for the e1000 when he originally posted this work for KVM.
    
    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
    
    
    
    git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5961 c046a42c-6fe2-441c-8c8c-71466251a162
    aliguori authored
     
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  • We're currently ignoring the e1000 VLAN tagging, stripping and filtering
    features in the e1000 emulation.  This patch adds backing for the
    relevant registers and provides a software implementation of the
    acceleration, such that a guest can make use of VLANs.
    
    This is mostly (only?) useful for a guest on a bridge (not user mode
    networking).  The only caveat beyond that is that you need to make sure
    the host NIC isn't doing it's own tagging, stripping, or filtering.
    This generally means the host NIC on the bridge should not be part of a
    VLAN.
    
    Signed-off-by: Alex Williamson <alex.williamson@hp.com>
    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
    
    
    
    git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5766 c046a42c-6fe2-441c-8c8c-71466251a162
    aliguori authored
     
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  • This patch fixes endianness issues in the e1000 nic emulation, which
    currently only works on little endian hosts with little endian targets.
    
    Byte swapping does not depend on host endianness, so this patch remove
    the use of cpu_to_le32 and le32_to_cpu functions. It depends on the path
    from the CPU to the device, which is currently and *wrongly* implemented
    in Qemu as a byteswap on big endian targets. This patch does the same
    as in other devices emulation as all the currently implemented targets
    work with this implementation.
    
    
    git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4046 c046a42c-6fe2-441c-8c8c-71466251a162
    aurel32 authored
     
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